Possible Ice Storm (Ryan)

SCENARIO DISCUSSION (DECEMBER 24-26 WINTER STORM)

I am somewhat on board for a disruptive winter storm (in the form of ice) beginning late Christmas Eve and ending very early Friday Afternoon on I-95, with areas west seeing a change to rain in the afternoon. The reason I think that is storm something to watch is the usual model act to underestimate the CAD situation. A prime example is obviously the Dec 9-12 event where the days in which MD was hit the CAD won out and LWX was forced to issue WWA's for the area. Some areas received 4 inches of snow in that case. In this storm, the upper levels will be warm, but the low levels will play an especially large hold on things this time. Another reason besides the usually underestimation of the CAD setup is the High pressure positioning. The High is being modeled as a 1038-1040 per the GFS. On the other hand, the NAM model has a high much further NE than the GFS. I am not liking either model's depiction of this storm. The snowpack that is currently here in the region will also play a large part in the system. Models don't usually factor this into their solutions while in reality, snow pack can mean 1-3 degrees on the temperatures. Snowpack also creates overnight lows that are cooler than expected. This brings me to the next factor, the nowcasting before now actually occurs. Let's be sure to monitor the actual lows tonight and tomorrow night and compare them to the forecast. If the lows are lower than forecast, it could be game on. There are things that do not support this storm though. One of those things is the fact that the warm air plume will be quite strong and it could take the surface temps right up. However, in this storm, it will be more likely for forecasters to bust on predicting less ice and getting more than predicting some and getting none.

In the Midwest, this will be a major blizzard and flooding threat for the Missouri Valley. Many areas in MN, SD, NE, WI, ND, and a few others will get over a foot of snow and high winds. The areas to the southeast of those states such as IA, IL, MI, KS, etc. will see wintry precip then going over to rain, with a large event still in store.

As of now, the intermountain west is getting hit hard by thsi storm system, and Denver, CO could be its next place of impact. All of the western mountains are seeing over a foot of snow and lower snow levels to boot.

The details of the track and definite impact will be posted on my site as soon as things become clearer. Thats all for me as of now, I'll have more soon.

Snow becoming heavier, Forecast (RYAN)

Hello again everyone, its Ryan with a Snowstorm Update. The snowstorm is becoming very paralyzing for the Mid-Atlantic/Northeast. Here in Dundalk, MD, there is heavy snow falling with 11'' on the ground. We are under Blizzard Warnings/Winter Storm Warnings as well.

My expected snowfall totals for the storm(from last night, Dec 17: 9PM)

WASHINGTON D.C.:20-25''
BALTIMORE: 20-25''
Dundalk, MD: 18-24''
Perry Hall, MD: 17-21''
Parkville, MD: 16-20''

There are plenty of things going on here with winds over 30mph and possible thundersnow developing. The snowfall rates will be increasing in the next few hours with 1-3'' through 4PM.

Here is the accumulation timeline for BALTIMORE:

10'' by 11AM
12'' by 12PM
15'' by 3PM
18'' by 5PM
20'' by 8PM
All these totals have a span of 1'' either way, and I will have more updates throughout this Record Breaking Blizzard.

Rain (RYAN)

All today's storm ending up being was a bit of rain with isolated spots of ice to the N and NW of DC/BAL metros. The storm ended up like this instead of a snow event because of the delayed timing until today rather than a more favorable day like yesterday.

I will update tomorrow possibly on this weekend's threat. (Good pattern setting up).

Update on Weekend storm (RYAN)

For this weekends storm, the update for you snow lovers is no good, which shows the much lower possibility of snow affecting the region.

Early Indications for some selected areas:

DUNDALK, MD
The precipitation could start out as a snow/sleet mix but in the matter of a few hours the precip should change to rain or freezing rain. The depiction will have to rest on the surface temperatures in this area along with any potential CAD. ACCUMULATIONS (SNOW C-1'') (Sleet T-0.1'') Ice (0.01-0.05'') (Rain .25-.4)

PERRY HALL, MD
For Perry Hall, the forecast is about the same however with the location being a bit north, there could be another hour or so of wintry precip, with the accumulations being the same as Dundalk. ACCUMULATIONS (SAME AS ABOVE)

JARRETTSVILLE, MD
The forecast has many similarities as well, but in this area, there could be 1-3 extra hours of wintry precip than Dundalk and Perry Hall due to a more north location which results in colder air, along with the possibility of stronger CAD. ACCUMULATIONS (SNOW:1-2'') (SLEET: 0.1-0.2") (ICE: 0.01-0.10'') (RAIN:0.1-0.2")

Coming up later will be updates as the models aren't handling the situation correctly and this forecast could drastically change, stay tuned.

First Call 12/11-13/09 (RYAN)

We have an interesting pattern setting up for the possible snowstorm this weekend. A low pressure entering the US off California has been in the models for several days now. Suppression has been a continuous factor in the implications of the storm, but the models have come around to showing the storm as a threat for 40 S mainly. Some of the models however, including a few residual runs show 40 N getting in on the snow action as well.

Here are some of the basic factors that first need to be examined: The HWO from the National Weather Service in Baltimore, MD/Washington D.C./Sterling, Va.
Disco: A LOW PRESSURE HAS THE POTENTIAL TO PRODUCE ACCUMULATING SNOW ON
SATURDAY INTO SUNDAY.

This is in relation to the NWS HWO which had accumulating snow in it before the 0-6’’ event this past weekend (Dundalk received 2’’.)

The AFD from LWX: LOPRES PASSES S OF AREA LT SAT INTO SUN...BRINGING RISK FOR
ACCUMULATING SNOW TO PORTIONS OF THE CWA. HIGH RMN WELL BELOW
NORMAL THRU MON.

I interpret this by looking at the weather models that DC/BAL are in good shape but Southern MD could face P-type issues.

Now a look at the models (GFS 12z,most reliable run)

850's for layer/temps
102 hours:

108:

114:

120:

126:

After viewing these models: I made a track of the precipitation in relation to the low pressure track:


I also completed a map in which shows the possible QPF areal coverage:

Finally, I made up a map of where I think snow will occur along with the rain and ice threats:

As to the setup, here is a 500mb vort image from 114 when the precip moves in our area of DC/BAL:

Some may some that the pattern at this time is quite zonal, and it is but the Polar Vortex position in Canada and a developing Greenland block will possibly let this storm works it magic and spread the precipitation.

At this point, it is unclear as to whether the storm will move up the eastern seaboard and impact I-95 directly from the storm.

This is only a first call and I will have quite a bit of more developed analysis when some details of this system become a bit clearer.

1st Call (Now a US forecaster) RYAN

Its Ryan again, and I am here to announce I am expanding some of my forecasting to include the US(the big storms) I am even doing some international work :)

With that in mind, my first wide out US map:


I will have an ice and possibly rain map in my final call.

Snowstorm Amounts, Ice Storm Possible (RYAN)

The snowstorm that occurred yesterday had surprises for many in the DC/BAL area. Some amounts to note were:
Perry Hall, MD: 1''
Dundalk, MD: 2''
Woodlawn, MD: 5.5''
Damascus, MD: 6''

This storm was covered on the accuweather.com forums. From now on, they will be discussed there, but this blog is once again active.

There is the potential for an ICE STORM this Tuesday Night into Wednesday Morning.

EARLY HINTS:

The national weather services Hazardous weather outlook for Central MD

A MIX OF WINTRY PRECIPITATION IS LIKELY TUESDAY NIGHT THROUGH
EARLY WEDNESDAY MORNING IN AREAS ALONG AND WEST OF INTERSTATE 95.
WHILE IT IS TOO SOON TO CATEGORICALLY DETERMINE THE EXACT
PRECIPITATION TYPE...THERE IS A GOOD CHANCE FOR IT TO BE FREEZING
RAIN AND SLEET.

Analysis: This shows that the NWS is hinted in on the chance for a Winter Storm, with Ice Storm being the one to focus on.

Our Synopsis from MDWX(How it could play out): The low coming across the Great Plains of the central US will gain strentgh and this could set up a claassic CAD(cold air damming) situation east of the Blue Ridge Mountains to I-95. It is too early to hone in on the exact timing of the precip, or how long it will last, but one thing is for sure; Wednesday afternoon the precip will change to all rain with temps in the 40's.

NWS Forecast for this period(Baltimore MD):
Tuesday Night: Freezing rain and sleet likely. Cloudy, with a low around 30. Chance of precipitation is 70%. New precipitation amounts between a half and three quarters of an inch possible.

Wednesday: Freezing rain and sleet likely before 9am, then rain likely. Cloudy, with a high near 42. Chance of precipitation is 70%.

Analysis: The bolded areas are my focus, and especially how there could be 1/2-3/4'' of precip in the freezing rain/sleet categories. What this means: A large Ice Storm with big effects is definitely a possibiliy and precip chances are already 70%, so this is something that HAS to be watched closely.

Next Update: This evening.

Official Winter 2009-2010 Forecast/Discussion

http://forums.accuweather.com/index.php?s=&showtopic=11883&view=findpost&p=582537

October 2009 Forecast/Discussion

October 2009 Forecast/Discussion

Temperature

Precipitation

Pattern

This month, I am expecting more of a +NAO pattern to set up which will allow for ridging on the east coast and some of the inland areas of the MidAtl/NE to get some good rainfall and the west should get into a temporary cooler/wetter pattern due to the effects of the PDO. I am also expecting a -EPO to set up and give the Great Lakes area some cool times.

Overall, this is what I am expecting by the parts of the month.

Oct 1-7, we are still in a -NAO pattern and are getting cool conditions on the east coast, though the west will be cool as at this time there will be a TZT pattern, NAO is negative, EPO is around neutral, AO is around neutral, and PNA is neutral.

Oct 8-14, a more zonal pattern develops at this time, NAO is around neutral, AO is positive, EPO is around neutral, and PNA is negative.

Oct 15-27, a +NAO is forming here and will give warmer temperatures to the East coast, by this time, the EPO shall be negative and the Great Lakes should have a cooler and potentially wetter pattern along with the west coast, the progressive pattern continues, NAO is positive, AO is positive, EPO is negative, PNA is neutral.

Oct 28-31, the pattern breaks and we go back to a more zonal flow, but this time we are still in a +NAO and the main storm track is shifted into the North country while the south is warm/dry, NAO is positive, AO is positive, EPO is negative, PNA is negative.

So there are my monthly thoughts, I will give more specific details in the October pattern thread.

Comments would be appreciated.

Final Winter 2009-2010 Discussion/Forecast

Winter 2009-2010 Forecast ''An Active Winter Ahead''!

Over the last 6 months, I have been watching the telleconnectors and factors of ENSO, QBO, SOI, PDO, etc and have used them and favored climatology and thinking with effort to make this forecast, Enjoy!
　
Part 1:Telleconnectors and Factors

ENSO[El Nino Southern Oscillation]

Since the previous Winter of 2008-2009, an El Nino has been forming, it has since gotten to a Weak category with some spots hitting Moderate like values at time, but has overall stayed weak. Here are the past and current weekly SST departures.
1:Weekly SST Map
The current values are as follows, Nino 1+2=+0.3C, Nino 3=+0.8C, Nino 3+4=+0.9C, Nino 4=+0.8C, trimonthly/average=+0.7C, as you can see, there has been no major warming in the last couple of months and SST values have either holded suit or have cooled slightly. Here is my prediction for the trimonthly SST values.

2:Trimonthly SST Prediction Map

As you can see, I am predicting that Weak El Nino conditions will be dominant through now until Wintertime, we may approach Moderate El Nino values in NDJ, but will most likely stay Weak, by spring, we should have neutral conditions. Unless we see another major warm pool soon, Moderate El Nino should not be reached. I would say right now that we are much more likely to have a West-Based El Nino then an East-Based because East-Based would favor warmer SST's.

PDO [Pacific Decadal Oscillation]
This year we are in a multidecadal -PDO year which gives bad chances for a Moderate to Strong El Nino and gives a better chance for a Neutral to La Nina like year. The PDO lately seems to be rising toward positive as waters in the eastern pacific coastline seem to be warming to a more +PDO like environment, this should help keep the El Nino going. A +PDO also gives us west coast ridging with warm waters and cool GOM and atlantic waters with a favorable south and east [+PNA]. I would say that positive may be accomplished, but since we are in a multidecadal year, this will most likely be around neutral. For clarification, this is what a PDO does in its phases.

3:PDO phases and SST correlation
Here is the current SST anamolies
4:Current SST anamolies

SOI [Southern Oscillation Index]
The SOI lately has been flip flopping between positive and negative, it is currently positive, when the SOI is positive, it helps keeps the equalatteral Pacific cooler than in its -SOI mode, SOI should continue switching between negative and positive in the next several months. Irrigardless, it has been supporting a Weaker El Nino as well.

Climatology

Normally, an El Nino, the warm phase of SST's puts warmer waters in the pacific ocean, especially areas around the equator. An El Nino favors warmth on the Western US coast, western Canada, and alaska with this able to spread into the Northern US while cooler and wetter conditions further to the south and east in the GOM area persist, here is a demonstration of a regular El Nino [Moderate to Strong]

5:Regular El Nino Winter Conditions

A Mod-Strong El Nino would block artic air from entering the US and would keep most of the North US warm with a rather strong High pressure near the Pacific coast while the Pacific Jet Stream is forced southward giving a further south track, the GOM area becomes an area of moisture filled storms in the Winter and give off there own cold in this case.
Now in a Weak El Nino, the area of high pressure in the Northwest is weakened and can be pushed northward giving more of a widespread stormtrack and not as warm conditions while the GOM is a breeding ground for moisture and very well affects the Gulf Coast states with this and forms lows riding up the coast affecting the East Coast in a Weak El Nino, with the more north storm track, more Miller B storms forming off the Mid Atlantic coast are found. El Nino's tend to favor a overall warmer Nov/Dec and a cooler Jan/Feb for the country.

Part 2:The Forecast

November 2009

From what I have been looking at, this November looks to favor normal El Nino means as it will still be trying to strenghen. I see the high pressure area strong and slightly further east this month giving the West, North, and Mid Country areas Above average Temperatures, the storm track will be further south this month affecting mainly the extreme southeast and Florida with storms mainly going OTS after it, pattern favors a Neutral NAO, Neutral AO, Positive PNA, and Negative EPO.

6:November 2009 Temperature Anamolies
7:November 2009 Precipitation Percent of Normal
8:November 2009 500mb Pattern

December 2009

I do know that El Nino's favor warm Temperatures in this month but for this Weak borderline Moderate El Nino, I am expecting that the high pressure area will be further north allowing for more cold and wet potential into the Southern US, the GOM will be now starting to get more moisture and there will be likely more and stronger storms forming in the GOM affecting the gulf coast with Above average precip and these storms will either go OTS or ride up the coast affecting the Mid Atlantic/Northeast, especially the eastern regions, these storms will once again create cooler conditions, pattern favors a Neutral NAO, Negative AO, Positive PNA, Negative EPO.

9:December 2009 Temperature Anamolies
10:December 2009 Precipitation Percent of Normal
11:December 2009 500mb Pattern

January 2010

In El Nino's, January can tend to be a turning point in the pattern, by January, we should start to see the El Nino weaken a little bit. I am going for a weaker high pressure area and once again further north, this month I believe the convection of the Gulf Of Mexico will really fire up and we very well could get a Wet/Snowy month for the Gulf Coast and East Coast, some areas may approach 150% of average precipitation. There will be lots of cold in these storms so the Mid Atlantic/Northeast should be on the lookout for some major snow with these storms, there is a high potential for a Noreaster with Heavy Snow this month as well as strong winds and Blizzard like charecteristics, I am also seeing a good chance of Miller B storms this month with the area of Low Pressure and development, like January 2005. Pattern favors a Negative NAO, Negative AO, a Positive PNA, and a Negative EPO, I am also expecting that the atmosphere may look Neutralish for the ENSO at times.

12:January 2010 Temperature Anamolies
13:January 2010 Precipitation Percent of Normal
14:January 2010 500mb Pattern

February 2010

February El Nino's favor to be one of the coolest months of the Winter, I am expecting that the El Nino will continue to weaken during this time. I am expecting that the western high will be mainly a nonfactor at this moment and the Northwest will start to get more precipitation, the South and East will continue to deal with many storms and ample moisture with coastal storms and more possible Miller B's, by this time we may have a Neutral to even Weak La Nina like pattern and have some overunning storms forming inland as we have a higher possibility of a -PNA this month, so it is likely that the Ohio Valley, and the Southern Great Lakes end up with colder and wetter/snowier conditions this month. Pattern favors a Negative NAO, Negative AO, Positive-Neutral PNA, and a Negative EPO. Ice potential is higher this month in storms.

15:February 2010 Temperature Anamolies
16:February 2010 Precipitation Percent of Normal
17:February 2010 500mb Pattern

March 2010

March's tend to be variable in weather since they normally come off an ENSO, the El Nino by this time will be gone and we will be in a Neutral State. I am forecasting that the axis of moisture will spread northward as the GOM starts to wind down due to the steering, I expect this month to be more of a inland track month which will favor the West, the Mid Country, and the Ohio Valley areas with above average precipitation, overunning events will be found this month. Pattern favors a Neutral NAO, Neutral AO, Neutral-Negative PNA, and a Negative EPO.

18:March 2010 Temperature Anamolies
19:March 2010 Precipitation Percent Of Normal
20:March 2010 500mb Pattern
　
Overall Temperatures
Temperatures this winter will be above average in the west and below average in the east with some months giving other patterns, but this will be the average.

21:Winter 2009-2010 Temperature Anamolies

Overall Rainfall
Rainfall will be below average in the west and above average in the east with some months giving other patterns, but this will be average.

22:Winter 2009-2010 Rainfall Percent Of Normal

Overall Snowfall
Snowfall will be below average in the west and above average in the east, especially in January and February where the storms will be cold enough to give heavy snowfall.

23:Winter 2009-2010 Snowfall Percent Of Normal

Other Information

Most of the storms near the major cities could be a rain or a rain/snow mix due to climatology and patterns, the above average snow will come from major storms in January and February.
All months will have cold fronts and warm fronts coming through the area time after time giving some precipitation.
The area of ice this winter will be from the Mid Region, through the Ohio Valley, and then into the Mid Atlantic when we get overunning events during a -PNA pattern, CAD may be a factor this winter as well.

City By City Forecast's
[Closest to Whole Number]

Washington DC:
Nov:+1
Dec:0
Jan:-3
Feb:-2
Mar:-1
Average:-1
Snowfall Percent:125%
Total Snowfall:20-25

New York City NY:
Nov:+1
Dec:0
Jan:-3
Feb:-1
Mar:-1
Average:-0.8
Snowfall Percent:100-125%
Total Snowfall:30-35

Chicago IL:
Nov:+2
Dec:+1
Jan:0
Feb:-1
Mar:-1
Average:+0.2
Snowfall Percent:100%

Dallas TX:
Nov:+1
Dec:0
Jan:-1
Feb:-3
Mar:-1
Average:-0.8
Snowfall Percent:100-125%

Denver CO:
Nov:+2
Dec:+1
Jan:0
Feb:-1
Mar:-2
Average:0
Snowfall Percent:75-100%

Seattle WA:
Nov:+4
Dec:+3
Jan:+1
Feb:+1
Mar:-1
Average:~1.67
Snowfall Percent:50-75%

That is my forecast, I will make more specific month by month forecast's once we get close to the month.

The numbers which come in order from 1 to 23 represent the images which are avaliable on the accuweather forums.

Comments would be appreciated!

Updated Winter 2009-2010 Forecast [September]

Mid September Winter 2009-2010 Forecast Update

I have noticed and done more research and it seems like it would be enough to update my forecast.
　
In the last couple of weeks, I have seen that the El Nino is struggling to strenghen and is starting to become more basin wide instead of East Based, here are the current SST values, Nino 1+2=0.5, Nino 3=0.8, Nino 3+4=0.9, Nino 4=0.8, in the last few weeks, Nino regions 1+2 and 3 have cooled off while regions 3+4 and 4 have remained consistent or slightly warmed up. This pattern right now is being caused because of the multidecedal -PDO, which tends to keep the SST's cooler, especially in the eastern regions.

Overall the changes I will make is to say the max SST values should be in the +1.0C to +1.5C range with overall Weak-Moderate El Nino conditions, IF we can have a strong -PDO and a consistent +SOI, this could weaken down to a Neutral event at any time. For the temperatures and precipitation, I moved the axis of cold/wet/snowy conditions and warm/dry conditions further north and west of the oringinal forecast. I also now would say that the most common type of precip this winter in the 1-95 should actually be rain or a mix of the 2, the snowfall will mainly come from strong and cold storms, wouldn't be suprised if we had a few inland storms as the NAO/AO/PNA will be fluctuating a lot this winter.

Comments would be appreciated.

September 9-12 2009 Verification

Final Forecast map on the top, Actual Rainfall on the Bottom, most likely slightly off.

Selected rainfall amounts.

Richmond, VA [KRIC]:0.04

Washington, DC [KDCA]:0.80

Baltimore, MD [KBWI]:1.71

New York City, NY [KNYC]:0.84

Boston, MA [KBOS]:1.81

My Location [PHMDWX]:3.43

Best Models:GFS/ECM

Grading

Precipitation:B:Was too widespread with amounts, but some locations verified great.

Track:A:Expected it to go through New Jersey

Overall:B/A:Did Well.

Comments, Suggestions, and Complements would be Appreciated.

September 8-11 Final Discussion/Forecast

September 8-11 Coastal Rain Storm Final Discussion/Forecast

Quite a bit has changed in guidance and forecast in the last 24 hours. The storm is now just off the North Carolina coast around Cape Hatteras, which is on track with the previous forecast. The 12z/18z NAM give the mid atlantic a lot of rain as it moves the storm slow, it dissapates it further south hence not much rain gets into New England. The 12z/18z GFS have a further east rain swath with the delmarva and eastern Mid Atlantic getting the most rain as this model is faster with the storm and makes the second low heading right near or just on the coast.
12z HPC model discussion.

LOW MOVING UP THE MID ATLANTIC COAST/SECOND CIRCULATION IN THE OH VALLEY/APPALACHIANS... PREFERENCE: A BLEND OF THE 12Z GFS/09Z SREFMEAN/12Z UKMET THE INITIALIZED LOW FURTHER EAST LEADS TO THE LOW STAYING EAST OF THE 00Z FORECASTS OF THE NAM/GFS/UKMET/ECMWF THROUGH THE FORECAST CYCLE...WITH ONE SFC-700 MB LOW OFF THE COAST AND ANOTHER 700 MB LOW INLAND OVER THE APPALACHIANS/OH VALLEY. THE 15Z ANALYSIS SHOWS THE LOW POSITION ABT 50 NM NORTH OF THE NAM FORECAST LOW...SO ADJUSTING THE NAM FCSTS CORRESPONDINGLY NORTH APPEARS TO BE IN ORDER. THE 12Z NAM/UKMET ARE SLOWER MOVING THE LOW NORTH OVER THE COASTAL WATERS ON DAY ONE/EARLY DAY TWO WITH BETTER CLUSTERING AMONG THE 06Z-12Z GFS/00Z-12Z UKMET/00Z-12Z ECMWF ON DAY TWO...WITH THE 09Z SREF MEAN CLOSE TO THE NAM SOLUTION. ON DAY THREE...THE ECMWF HAD THE MOST WESTWARD PROGRESSION ACROSS PA WITH THE SFC LOW...AND THE CANADIAN FURTHEST NORTH. I RECOMMENDED GIVING LESS WEIGHT TO THE CANADIAN GLOBAL SINCE THE STRONG HIGH OVER NEW ENGLAND SHOULD BLOCK NORTHWARD MOVEMENT. WITH THE HIGH MOVING OFF THE NEW ENGLAND COAST...THE RAPID INLAND MOVEMENT OF THE ECMWF APPEARS TO BE OVERDONE. THE MODELS WERE IN GOOD AGREEMENT ON DAY ONE WITH THE EXISTING CIRCULATION IN THE OH VALLEY AT 700 MB DRIFTING SOUTH INTO KY ON DAY ONE AND SHEARING OUT. BIGGER DIFFERENCES DEVELOP ON DAY TWO-THREE AS THE MODELS DIFFER AS TO THE EVOLUTION OF THE CLOSED LOW OVER THE MID ATLANTIC AND WHETHER IT CROSSES THE APPALACHIANS INTO THE UPPER OH VALLEY/ADJACENT LOWER LAKES BY FRI. THE 12Z NAM REMAINS ON THE SOUTH EDGE OF THE SUITE OF 700 MB LOWS ON FRI...WITH THE ECMWF/UKMET/CANADIAN/06-12Z GFS/06Z-12Z GEFS MEAN/09Z SREFMEAN SHOWING THE CIRCULATION FURTHER NORTHEAST.

As of right now, I would go with a blend of the 18z NAM/GFS and 12z GGEM/ECM for this storm.

HPC is going with a more wet solution which I won't argue with, here is there short range discussion.

SHORT RANGE FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 450 PM EDT TUE SEP 08 2009 VALID 00Z WED SEP 09 2009 - 12Z THU SEP 10 2009 AN AREA OF LOW PRESSURE NEAR THE OUTER BANKS OF NORTH CAROLINA IS EXPECTED TO MOVE VERY LITTLE DURING THE NEXT 48 HOURS. THE SYSTEM WILL REMAIN JUST OFF THE MID ATLANTIC COAST LINE AND GRADUALLY BECOME ABSORBED BY A COLD FRONT AND ASSOCIATED HIGH PRESSURE DESCENDING OUT OF NEW ENGLAND AND THE CANADIAN MARITIMES. EASTERLY LOW LEVEL FLOW BETWEEN THE LOW AND THE HIGH TO THE NORTH WILL CONTINUE TO PRODUCE CLOUDY...COOL AND EXTENSIVE RAINFALL ALONG THE OUTER BANKS...THE DELMARVA...SOUTHERN CHESAPEAKE AND DELAWARE BAYS. INLAND ALONG THE I-95 CORRIDOR FROM RICHMOND TO BOSTON...PERIODS OF LIGHT RAIN AND OCCASIONAL SHOWERS WILL BE THE PREVAILING WEATHER CONDITIONS DURING THE 24 TO 48 HOURS.

HPC day 1-3 QPF forecast is at the top of the post.

As you can see, the HPC is going is going with a widespread 1-3 inches in the Mid Atlantic with the heaviest rain in the delmarva area to southern New Jersey.
For my forecast and thoughts, once again I am going with the latest NAM/GFS solutions and the 12z run of the GGEM/ECM.

I am forecasting a slightly faster movement of the low[s] and the second further north hybrid low, subtropical in nature will form like the GFS is currently showing and should hug the coastline or go slightly inland while the original low stays further south and goes OTS. The faster movement we have, the more ground this storm will affect, so I am seeing a good widespread rainfall across the Mid Atlantic and Southern New England.

The major cities, Washington, Philadelphia, New York, and Boston look to get a general 1-3 nches of rain while to the northwest, there will be ligher rain less than 2 inches and a Trace to an inch in the interior regions, while the coastal Mid Atlantic area could see a good 2-4 inches being in the heaviest area of rain and close to the Hybrid Low.

Here is what I am predicting for the cities.
Richmond, VA:Around 0.5
Washington, DC:Around an inch
Baltimore, MD:1-2 inches
Philadelphia, PA:1-3 inches
New York, NY:1-3 inches
Boston, MA:Around an inch

With this, there could also be some breezy conditions around the coastal areas, in the range of 15-30mph locally, with that some possible coastal flooding and beach erosion.

That is my discussion and forecast on this storm, this is my final one irrigardless of what happens, everything you see above won't be changed, though some differences from guidance and forecasts could be possible.

Comments would be appreciated.

September 7-11 2009 East Coast Rain Storm Forecast

There is a low pressure area just off the North Carolina coast bringing rain currently to North Carolina and Virginia, here is what model guidance is saying so far.

12z GFS:Brings the system over cape hatteras and then slows it down keeping it just off the Mid Atlantic coast giving them good rains, before slowly moving northeast staying just off the coast. Gives the DCA/BWI/PHI/NYC area 1-2 inches of rain and the delmarva 3-7 inches of rain.
12z NAM:Takes this just off the coast and then dissapates this but not before giving a widespread 2-6 inches of rain in the Mid Atlantic region.
12z GGEM:Moves this slowly and low stays right near the coast and eventually the main low goes inland, gives the major cities a good 2-3 inches of rain and a good several inches in the delmarva. The main shaft of rain moves north into the interior northeast.
12z UKMET:Keeps low off the coast and gives the Mid Atlantic rain.
12z ECM:Keeps low near the coast.

For the 12z guidance, I would have to go with the GFS/NAM/ECM in terms of precipitation and

track.

I am expecting a track going from near cape hatteras then slowly moving up the coast until getting shafted out to sea near southern New England sparing them of heavy rain, this should gradually weaken as it starts to head north and east. For rainfall, I generally agree with NWS/HPC means so I am expecting a widespread 1-3 inches of rain for all of the major cities except for Boston and a potential area of over 3 inches of rain in the delmarva region. There could be some breezy conditions near the coastal areas as well with this storm, you can see my

map and some of the details above.

So that is my forecast and I am sticking too it.

Comments would be appreciated.

Winter 2009-2010 Redone Maps

2nd Winter 2009-2010 Discussion/Forecast

Here is my second Winter 2009-2010 discussion/forecast.

Just to clarify, we are one day from Labor Day and we are currently 3 months from meteorogical winter.

First off, the factors and the telleconnectors this winter.

ENSO:The SST values at the lastest update are as follows, Nino 1+2=0.8C, Nino 3=1.0C, Nino 3+4=0.9C, Nino 4=0.9C, as you can see, we are in a Weak El Nino state, forecasts are predicting a Moderate El Nino to form with a little more warming in the Pacific. Forecasts were originally calling for a Strong El Nino potentially rivaling the years of 1982-1983 and 1997-1998, but have overestimated it, I am calling for a Moderate El Nino to form with a max SST value in the range of +1.2C to +1.5C, but with a potential of this staying a Weak El Nino with the right factors.

PDO:The PDO is negative right now and is in a multidecadal -PDO phase and is expected to stay that way through wintertime, historically this is known to keep a Strong El Nino away and would help us in having a Weak-Moderate El Nino.

SOI:The SOI has been flipping between positive and negative in the last couple of months, historically if the SOI is positive for the majority of the time, it will help keep the El Nino weak, the SOI should continue flipping through the next couple months, hence it shouldn't be that much of a concern.

Tropical Influence:I know that this may not be considered to mean anything, but this has been considered to churn up the waters and cool them down in the northern GOM and in the Western Atlantic and can influence the weather in the United States, if we get more storms, this could help us in getting more storms.

Now how will this play out in the Winter with the El Nino effecting the Jet Stream, Temperature, and Precipitation patterns.
Overall, this winter will have 2 different areas of effectence.

First is the Northwest, Great Plains, Midwest, and Great Lakes:This area should have mainly Above average Temperatures, and Below average Rainfall/Snowfall, this area will not have that much storms as the jet stream will keep the storms weak and further south in this area and the Pacific will be bringing Warm Temperatures as it will be controlling, the mountain areas will also not fare well with snow this year, the only possible storm system track would be from Alberta Clippers coming from Canada and then possibly effecting the Great Lakes, Midwest, and then possibly down into the Mid Atlantic/Northeast.

The second area is the Southeast, South Central States, the Mid Atlantic region, and possibly coastal areas of the Northeast:This area should have mainly Below average Temperatures, and Above average Rainfall/Snowfall, this area could have a very active winter as most of the storms will be coming from the northern Gulf of Mexico with an active southern jet stream, this could give lots of rain and snowstorms starting near the GOM area and then riding up the coast affecting the east coast, these could also go OTS if the prevailing factors help that, there could also be some strong Noreasters, Heavy Snow storms, and even some Blizzard like storms this winter. If you want snow in the interior Southeast and Mid Atlantic areas, this could be your winter if we can get factors right. This winter could also have some alberta clippers giving potentially more snow to the Mid Atlantic/Northeast, and possibly even some overunning events with ice potential when the southern jet stream relaxes to the Ohio Valley, Mid Atlantic, and Southern New England areas, we could also have an active LES season.

For the telleconnectors this winter, the main factor will be a +PNA for most of the winter which will give us the active southern jet stream, the NAO/AO/EPO will mainly fluctuate, if it was on a side, I would say it would be closer to negative,also these may be more east based at times. The greenland block should be avaliable at a lot of times, once again, we could get ice storms if the PNA becomes negative.

I am not really sold yet in what I am predicting monthly, but here it is, in the regions I mentioned above.

Area 1:December:Warm/Dry
January:Warm/Dry
February:Average to Warm/Dry
March:Near Average

Area 2:December:Average to Slightly Cold/Wet/Snowy
January:Cold/Wet/Snowy
February:Cold/Wet/Snowy
March:Near Average

If all of the above ends up true, I would go with analogs for this Winter of 1976-1977, 1977-1978, 1992-1993, 2002-2003, and 2006-2007.

So for my forecast to have a decent chance of verifying, here is what needs to happen in the next 3 months.

El Nino needs to stay Weak-Moderate, PDO needs to stay negative, SOI needs to fluctuate, Tropical weather needs to be active.

If that works out, this is what you can expect for this Winter.

Moderate El Nino, potentially Weak if factors help.
Warm/Dry Northwest, Great Plains, Midwest, and Great Lakes.
Cold/Wet/Snowy Southeast, South Central, Mid Atlantic, and potentially the coastal Northeast.
Active Southern Jet Stream effecting the Southeast and East Coast with Rain/Snow.
Potential for Alberta Clippers.
Potential for Overunning Events when Southern Jet Stream relaxes.
Potentially active LES season.
+PNA for most of the Winter.
Near neutral NAO/AO/EPO for most of the Winter, potentially leaning toward Negative and East-Based.

So that is my forecast, my next full one will be out in about a month.

Comments would be appreciated.

Tropical Storm Erika Discussion/Forecast 3

Erika is gradually weakening overtime as this has went through the eastern carribean islands, it is barely hanging on as a Tropical Storm with winds of near 40mph. It is currently around 16.6N, and 64.7W, moving West around 9mph with the minimal central pressure of only 1008mb. Now what is interesting is that there have been major convection forming over the last night and almost wanted to move the COC further to the North/East where the healthiest convection was, otherwise since then, this has again diminished.

12z Model Runs and thoughts.

GFS:Strenghens this and runs this up the coast, big difference from past runs, though a little too strong and too far east in my opinion.

NAM:Holds it near tropical storm status and runs just east of the islands, once again a little bit too strong and east in my opinion.

GFDL and HRWF look too strong and too far east, though it is normal for them to have a high wind forecast because they are hurricane models.

The other models either send this into the western atlantic or turn it into a open wave.

In my opinion I believe some of the models are still strenghening this too much, notice that the pressure has dropped since the 11am update, infact I wouldn't be suprised if this becomes a Tropical Depression at the 5pm advisory, the shear and its location are tearing Erika apart, albeit she is still not giving up. For model tracks, same problem, they are sending this off NW right from initialation while the actual storm is heading about due west, hence this has a good chance of going south of some of the models forecasts. Some of the models are also wrong in speed as well. Unless we can get another good flareup of convection, Erika should become a Tropical Depression within possibly the next several hours.

For my forecast, I have once again shifted my forecast further to the south and west and have lowered my strengh forecast by quite a bit. I am expecting a W/WNW movement for the next 12-24 hours and that this will be a Tropical Depression by tomorrow afternoon, then this should turn more to the northwest going near the islands and then by about 120 hours this should make landfall, I am now expecting Florida as the lanfall location. By then this could not be even a Tropical Depression, just a Low or tropical wave depending on location, then it should stay inland but still not far from the coast as it gradually dissapates. This should not bring that much concern except maybe some rainfall and some breezy winds, otherwise that is about it, The National Hurricane Center also does this. You can see my predictions on track, strengh, and speed on the map above.

Now, ofcourse since we are not 100% sure on the track and strengh so there are a couple of possible scenarios.

Scenario 1:This goes as me and most forecasters expect it too and slowly weaken and head off to the W/WNW/NW likely making a southeast coast landfall.

Scenario 2:This somehow fights the shear again and starts to reform itself again and continue as a tropical storm, in this case this would likely make a NW turn and eventually N turn quicker and potentially miss land but still with a possible effect as a Tropical Depression or Tropical Storm.

Scenario 3:This ends up going futher south then predictions and immediatly weakens to a Tropical Depression and possibly a open wave low and heads near or over Cuba and Jamaica and then tries to reemerge somewhere near of just south of key west, and then heads into the GOM.

Percentages for the scenarios.

1:50%

2:30%

3:20%

Note that I do agree with the NHC on track and strengh, ofcourse this may change. Still folks from Texas to Florida to Maine should monitor this as a lanfall could happen in any of these places, if it is still a technical low then.

Comments would be appreciated.

Tropical Storm Erika Discussion/Forecast 2

Tropical Storm Erika has formed over the last 24 hours, but with shear and approximity to the islands, this has weakened to a 40mph Tropical Storm. The current information as of 2pm are this is at around 16.2N, and 61.1W and is moving west, 265 degrees at 10mph with a pressure of 1008mb.

Here are the 12z models

GFS, keeps the storm weak and to the south near the carribean islands.

NAM, sends this to the western atlantic with a likely southeast/mid atlantic landfall.

GFDL, strenghens this to a Cat 3 and sends this into the islands southeast of florida and likely a southeast landfall.

HRWF, sends it to a strong hurricane and moves it slightly east of the islands and possibly a Southeast/Mid Atlantic landfall.

GGEM, sends this through the islands and weakens it a lot.

UKMET, keeps this south near the islands.

NOGAPS, gets this strong and sends it up the coast.

ECM, sends this near the coast.

So with the 12z guidance, this is continuing to shift west. Most models have this coming toward the east coast as some sort of Low pressure area, either a weak low or just Erika still. The reason why this is staying weak is that the shear has taken hold once again and has taken away a lot of the major convection from last nights blow up. The reason why this is further south and west as oringinally modeled is because this storm is staying weak and steering currents are alluding to this, if this storm can get stronger, we may see a more NW track, but until then, we should expect a westward track with this. The GFS/GGEM keep this storm very weak while the GFDL/HRWF and NOGAPS strenghen this storm to hurricane status. So far, I am agreeing with the NAM, UKMET, and ECM for strengh.

Now for my forecast, I am expecting that this should gradually start to gain more strengh at a slow speed in the next coming days, which should turn this more toward the NW, and then eventually possibly north, I am now expecting a landfall from this, instead of me expecting an OTS solution like I did yesterday, the best lanfall zone IMO is around the Carolinas before heading north most likely slightly inland and then hang near the coast as it starts to head NE. Now if Erika can strenghen herself more and faster than predicted, this storm will most likely take a more easterly track and most likely not hitting land, on the other hand, if she continues to struggle in strenghening and becomes a Tropical Depression or stays a weak TS, she will most likely go near the islands and possibly into the GOM. But right now, everyone from about Louisiana to Florida to Maine should watch out for a lanfall. I have posted my thoughts on track, strengh, and timing in the map above. Everyone should stay alert right now as I am expecting that this could potentially grow into a stronger tropical storm.

Comments would be appreciated.

Invest 94L Discussion/Forecast 1

In the last few days, a tropical wave has developed in the atlantic ocean and has since became an invest, so far this is trying to fight shear hence the reason that this is still only an invest, but latest recon observations have reported 50-60mph winds so this may and likely will become either a depresson or Erika within 12-24 hours. Current 2pm location is 16.8N, 57.2W and drifting to the WNW at about 9mph.

Now lets look at the latest model runs.

The 12z GFS is keeping this weak and south, low goes through the northern carribean islands.

The 12z NAM also keeps this weak and sends it toward the southeast coastline.

The 12z GFDL has this getting to a Cat 2 hurricane and keeping it east.

The 12z HRWF has this getting to a Cat 3 hurricane and following 12z GFDL

The 12z GGEM has this storm strong and rides near the coast.

The 12z NOGAPS has this riding near the coast.

The 12z ECM has this storm slow and takes this storm near the coast but most likely OTS.

So generally most model guidance has some kind of track through the Western Atlantic or landfall on the East Coast. The GFDL/HRWF, hurricane models can have a bias of strenghening the storm to much, this also applies to the GGEM model. The GFS/NAM/GGEM/NOGAPS have a westward/coastal solution while the GFDL/HRWF/ECM have a eastern solution, while the consensus of global models are west, the ECM, which is a great model,is not west, so I am taking that to mind as well.

For my prediction, I am mainly agreeing with the NAM/NOGAPS/GGEM for track, and the GFS and ECM for strengh. I am predicting that this will move into the western atlantic as a Tropical Storm or Hurricane and may even stay off the coast overall, while I believe this is a possible solution IMO, this could easily go west of there with a lanfall or even a GOM track, I.E GFS. Remember we got plenty of time left so this could easily change.

Comments would be appreciated.

Tropical Storm Danny Discussion 1

We have a new Tropical Storm and his name is Danny, he is currently moving in a WNW/NW direction heading toward the US.

Track

The models have been all over the place on this, we have the ECMWF/GGEM/UKMET/NOGAPS/GFDL heading for a Coastal storm and maybe even getting inland while we have the GFS/HRWF on the east side. The average of the models have this going near cape hatteras, then moving NNE/NE going near the coast.

Strengh

Models have this as a Tropical Storm or a Category 1 Hurricane at maximum speed.

I am predicting that this will be a coastal hugger.

Here are the percentages of a situation.

Mainly off coast:1 or 2 lanfalls:60%

Mainly inland:40%

Comments would be appreciated.

Danny is Born

Hi, its Junior Met Ryan with an update on Invest 92L. The invest had jumped right to a tropical storm with winds of 45mph. the storm is moving to the WNW at 1mph and its estimated central pressure minimum is 1009mb. Here is the forecasted track from the NHC. Expect updates from Chris, Nick, and I later on this storm. I may have my brief out late tonight. Stay tuned, and here is the NHC track image:

Invest 92 Potential Impacts

More detailed discussion will be made either later today or tomorrow, remember that this could go anywhere from OTS to west of the major cities ATM.

Bill Update RYAN

Hey it is Ryan with a Bill Update. Even though Bill is north of the area, all of the east coast is getting large waves, dangerous rip currents, and beach erosion. SE Massachusetts will have impacts along with those including Tropical storm force conditions. After all they are under TSW on Cape Cod, Martha's Vineyard, and Nantucket. Atlantic Canada may see landfall. Here is the NHC 8:00 PM Intermediate Advisory: 000
WTNT33 KNHC 222331
TCPAT3
BULLETIN
HURRICANE BILL INTERMEDIATE ADVISORY NUMBER 30A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
800 PM AST SAT AUG 22 2009

...BILL MOVING NORTHWARD...EXPECTED TO PASS OFFSHORE OF NEW ENGLAND
TONIGHT...

A TROPICAL STORM WARNING REMAINS IN EFFECT FOR THE EAST COAST OF
NOVA SCOTIA FROM CHARLESVILLE TO POINT ACONI. A HURRICANE WATCH
REMAINS IN EFFECT FOR THE EAST COAST OF NOVA SCOTIA FROM ECUM SECUM
TO POINT ACONI.

A TROPICAL STORM WARNING REMAINS IN EFFECT FOR THE COAST OF
MASSACHUSETTS FROM WOODS HOLE TO SAGAMORE BEACH...INCLUDING THE
ISLANDS OF MARTHAS VINEYARD AND NANTUCKET.

A TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE NORTHERN COAST OF
NOVA SCOTIA FROM NORTH OF POINT ACONI WESTWARD TO TIDNISH...FOR THE
WESTERN COAST OF NOVA SCOTIA FROM FORT LAWRENCE TO CHARLESVILLE...
AND FOR PRINCE EDWARD ISLAND FROM VICTORIA IN QUEEN COUNTY
NORTHWARD TO LOWER DARNLEY IN PRINCE COUNTY. A TROPICAL STORM WATCH
IS ALSO IN EFFECT FROM PARSONS POND AROUND THE WESTERN...
SOUTHERN...AND EASTERN COASTS OF NEWFOUNDLAND TO HARBOUR DEEP.

INTERESTS ELSEWHERE ALONG THE COAST OF NEW ENGLAND AND IN THE
CANADIAN MARITIMES SHOULD MONITOR THE PROGRESS OF BILL.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA
OUTSIDE OF THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY
YOUR NATIONAL METEOROLOGICAL SERVICE.

AT 800 PM AST...0000 UTC...THE CENTER OF HURRICANE BILL WAS LOCATED
NEAR LATITUDE 37.8 NORTH...LONGITUDE 68.3 WEST OR ABOUT 255
MILES...415 KM...SOUTH-SOUTHEAST OF NANTUCKET MASSACHUSETTS AND
ABOUT 550 MILES...880 KM...SOUTH-SOUTHWEST OF HALIFAX NOVA SCOTIA.

BILL IS MOVING TOWARD THE NORTH NEAR 24 MPH...39 KM/HR. THIS MOTION
IS EXPECTED TO CONTINUE TONIGHT WITH A GRADUAL TURN TO THE
NORTH-NORTHEAST ON SUNDAY. ON THE FORECAST TRACK...THE CORE OF
HURRICANE BILL SHOULD PASS OFFSHORE OF THE COAST OF NEW ENGLAND
TONIGHT...MOVE OVER OR NEAR NOVA SCOTIA ON SUNDAY...AND BE NEAR
NEWFOUNDLAND SUNDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 85 MPH...140 KM/HR...WITH HIGHER
GUSTS. BILL IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. WEAKENING IS EXPECTED TO BEGIN ON SUNDAY AS BILL MOVES OVER
COOLER WATERS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO
275 MILES...445 KM.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 961 MB...28.38 INCHES.

TOTAL RAIN ACCUMULATIONS OF 3 TO 5 INCHES WITH ISOLATED MAXIMUM
AMOUNTS OF 7 INCHES ARE EXPECTED NEAR THE TRACK OF BILL ACROSS NOVA
SCOTIA...PRINCE EDWARD ISLAND AND NEWFOUNDLAND. 1 TO 2 INCHES OF
RAIN ARE EXPECTED OVER NANTUCKET ISLAND...WITH AROUND 1 INCH
EXPECTED OVER OUTER CAPE COD AND MARTHAS VINEYARD.

LARGE SWELLS GENERATED BY HURRICANE BILL WILL CONTINUE TO AFFECT
MUCH OF THE U.S. EAST COAST AND SPREAD INTO THE ATLANTIC MARITIMES
OF CANADA TONIGHT AND SUNDAY. THESE SWELLS WILL LIKELY CAUSE
EXTREMELY DANGEROUS SURF AND LIFE-THREATENING RIP CURRENTS. SWELLS
FROM BILL ARE STILL AFFECTING THE BAHAMAS AND BERMUDA BUT SHOULD
GRADUALLY DIMINISH TONIGHT.

...SUMMARY OF 800 PM AST INFORMATION...
LOCATION...37.8N 68.3W
MAXIMUM SUSTAINED WINDS...85 MPH
PRESENT MOVEMENT...NORTH OR 360 DEGREES AT 24 MPH
MINIMUM CENTRAL PRESSURE...961 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 PM AST.

$$
FORECASTER BRENNAN

And here is my brief on Bill's future track. Here is the updated steering currents image close up Mid-Atlantic/Northeast view and a map with my expected track integrated on it.

Saturday 0z Bill Discussion

Final Bill Discussion

Hurricane Bill has weakened to a Category 2 at the moment and is currently moving Northwest, 345 degrees at 20mph. 11pm location was 31.0N and 67.5, Hurricane Bill is expected to move in a northward direction until getting closer to cape cod where it then will turn NE away from land, models are basically done trending at the time being.

Since I have explained the factors and forecasts multiple times, I will just skip to the forecast, this should move northward until around 40 north when this moves northeast, about 300-500 miles from land maybe a landfall in canada, strengh will be at a low Hurricane level.

Comments would be appreciated.

Tornado Warning

Hi, It's Ryan. Possible tornado in Maryland, heres the warnings.

First the Tornado Warning: TORNADO WARNING
MDC013-021-027-031-212345-
/O.NEW.KLWX.TO.W.0012.090821T2316Z-090821T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
716 PM EDT FRI AUG 21 2009

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* TORNADO WARNING FOR...
NORTHWESTERN HOWARD COUNTY IN CENTRAL MARYLAND...
NORTH CENTRAL MONTGOMERY COUNTY IN CENTRAL MARYLAND...
SOUTHWESTERN CARROLL COUNTY IN NORTH CENTRAL MARYLAND...
SOUTHEASTERN FREDERICK COUNTY IN NORTH CENTRAL MARYLAND...

* UNTIL 745 PM EDT

* AT 713 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM WITH STRONG ROTATION NEAR GREEN VALLEY...MOVING
EAST AT 20 MPH.

* LOCATIONS IMPACTED INCLUDE...
GREEN VALLEY...
DAMASCUS...
MOUNT AIRY...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE NEAR THE PATH OF THIS STORM...TAKE COVER NOW! IF NO
UNDERGROUND SHELTER IS AVAILABLE MOVE TO AN INTERIOR ROOM ON THE
LOWEST FLOOR. MOBILE HOMES AND VEHICLES SHOULD BE ABANDONED FOR MORE
SUBSTANTIAL SHELTER. AVOID WINDOWS!

&&

LAT...LON 3940 7710 3919 7708 3923 7735 3934 7735
TIME...MOT...LOC 2317Z 263DEG 16KT 3930 7730

$$
PELOQUIN

Now the Severe Thunderstorm Warning: Severe Thunderstorm Warning

SEVERE THUNDERSTORM WARNING
MDC013-021-027-031-220000-
/O.NEW.KLWX.SV.W.0212.090821T2307Z-090822T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
707 PM EDT FRI AUG 21 2009

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
HOWARD COUNTY IN CENTRAL MARYLAND...
NORTHERN MONTGOMERY COUNTY IN CENTRAL MARYLAND...
SOUTHEASTERN CARROLL COUNTY IN NORTH CENTRAL MARYLAND...
SOUTHEASTERN FREDERICK COUNTY IN NORTH CENTRAL MARYLAND...

* UNTIL 800 PM EDT

* AT 705 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS. THESE STORMS WERE LOCATED ALONG A
LINE EXTENDING FROM NEW MARKET TO BOYDS...AND MOVING EAST AT 25
MPH.

* LOCATIONS IMPACTED INCLUDE...
NEW MARKET...
GAITHERSBURG...
DAMASCUS...
MONTGOMERY VILLAGE...
GREEN VALLEY...
MOUNT AIRY...
OLNEY...
SYKESVILLE...
ELDERSBURG...

HAIL TO THE SIZE OF PENNIES AND WIND GUSTS TO 60 MPH CAN BE EXPECTED
IN THE WARNED AREA. STAY INDOORS AND AWAY FROM WINDOWS UNTIL THE
STORM HAS PASSED.

LAT...LON 3946 7688 3943 7690 3940 7689 3937 7690
3935 7688 3934 7688 3931 7684 3914 7683
3911 7735 3943 7737 3955 7686
TIME...MOT...LOC 2307Z 269DEG 20KT 3941 7735 3917 7729

$$
PELOQUIN

Stay safe. I may have to get off as its heading my way. I may update on the situation.

http://radar.weather.gov/radar.php?rid=lwx&product=N0R&overlay=11101111&loop=no CHECK OUT THAT LWX RADAR LINK.

Friday 0z Bill Discussion

Hurricane Bill continues as a category 3 storm and is moving Northwest at 18mph, this should continue for about 12-36 more hours until we get more of a NNW/N turn. The models and forecasts have generally stopped trending as Bill is on track with current forecast and model guidance.

Over the last 24 hours, Bill has moved on a Northwest course, on track with the current guidance. Current models are showing a northwest track for about 24 more hours and then will turn more NNW/N and get to near 70w before starting to turn NNE/NE at 35N to 40N not to far from cape cod, mainly 100-400 miles away. The UKMET, and NOGAPS have been constently showing a further west solution with them coming near 100 miles from the cape while models like the NAM and ECM are showing this near 400 miles away from it. So we still don't have full model agreement and likely models will eventually stay, move further west or further east. Also models are showing the rather strong subropical ridge, a US neutral/negatively tilted trough, and a cold front, these all change the places of the models and their affectance. For strengh, most models are showing a category 3/4 max range with low shear in the area will most likely strenghen this once more.

Now for my forecast, I am forecasting that this Northwest movement will continue for another 12-36 hours before it gets closer to the trough and will start turning NNW/N eventually riding its neutral/negative tilt until somewhere around 35N and 70W when the steering and cold front cause this to start to move NNE/NE most likely staying in the sea about 100-300 miles from cape cod before moving toward the eastern canada area and into the northern atlantic. This will be running into the upper level low and won't be effected that much by the subtropical ridge and the trough and cold front will be the ones affecting its position, for my best forecasts and models of choice, I would choose the NHC, GFS, and ECMWF as I beleive they have the best charecteristics.

Here is what I am predicting for percentages of where this goes.

Out to sea, over 300 miles from land:10%

Middle Path, 100-300 miles from land:70%

West Path, under 100 miles from land:20%

For the strength of Bill, it is currently a 125mph Category 3 Hurricane, and I am expecting this to most likely strenghen back up to a category 4 storm with low shear. Once again, if I has to take a guess, I would have to say the strongest wind speed will be in the 140-150 mph zone. As this moves further north, the cooler water temperatures will help weaken this once we get above around 35N, this should be a Weak Hurricane, about a category 1 or 2 once this has its closest approach to land. You do not want to be in this storm with these strong winds, so get ready for it if needed.

Even though this will most likely miss land, this should cause high waves and rip currents across most of the Mid Atlantic and Northeast coastal areas, which some are already getting affected by this, if you go to the beach, make sure you know what you are doing. There may also be some rain and wind with this, especially in the Southern and Eastern New England areas.

So although I am not expecting a landfall with this, I will warn that we are not out of the woods for major effects on the eastern seabord or Bermuda, I still warn that you folks should watch this storm closely and take precautionary action if needed as this may not be done changing in forecasts and models as it is possible that the storm, subtropical ridge, US trough, and cold front will change position, strengh, and speed. So once again, I am expecting this to get only about 100-300 miles from land, so effect is likely.

Comments would be appreciated.

Thursday 0z Bill Discussion

Hurricane Bill is continuing to strenghen and move North West, the current wind speed is 135mph Category 4 and is moving Northwest, about 305 degrees at 17mph. The model and forecast guidance overall is still slightly moving further west as the northward turn is not coming to friction when it was modeled to.

The latest models are still generally shifting west, most runs now have this going west of bermuda and within effecting distance of Southern New England, some models like the GFS Ensembles, UKMET, and NOGAPS come close to the cape area and come near 100 miles away giving them rain and wind. Otherwise, the rest have this going further east but still west enough for some effect. The shift west has been caused by a speedier than progged storm, a further south storm with a stronger subtropical ridge, and a slower than expected United States trough, which should become Neutral/Negative and ride this up the coast Northwest then Northward until the front gets to it and pushes it more northeastward. Once again, it is not just forecasting time, it is nowcasting time as well with current observations.

For my forecast, I am expecting this to continue on a NW motion for another 24-48 hours possibly, then it will get closer to the Negatively tilted trough and turn Northward, by then we should be about 70w with the storm, and then once it gets closer to the incoming cold front, this will turn it Northeast racing toward near Southern New England, most likely getting only 100-200 miles away. If the trough slows down, this could be a more coastal situation and run up near the coast or an OTS situation if the trough speeds up, you can see my map above with the black line representing the most likely path. Here is what I am expecting for percentages of a solution.

Out To Sea, near or east of bermuda, little to no effect:10%
Middle Path, goes about 100-200 miles from the CAPE, decent effect especially SNE:60%
Coastal Path, landfall, major effects, especially on SNE:30%

Now for strengh, it is currently a Category 4 135mph Hurricane, with the current observations, models and forecasts, they say that this will peak at Category 4/5 strengh, if I had take a guess, I would say the top wind would be about 150mph with this. If anyone gets hit by this, you will have to prepare for the strong winds.

Now how this verifies comes down to the speed, location and strengh of Bill, the location and strengh of the ridge, and the location and speed of the Trough and Cold Front.

I still warn that folks in the Mid Atlantic and Northeast, with Bermuda should be watching this one closely and take precautionary action if needed, this storm is stronger than some think and it may cause threats to structures and people, so I advise watch this storm as the track may change a lot more.

Comments would be appreciated.

Wednesday 0z Bill Discussion

I have been following the latest observations of the Hurricane and they are showing a WNW/NW movement at the moment, this hurricane is also still strenghening rather quickly.

Once again, the reason why we are continuing the WNW/NW movement instead of the more NW/NNW/N movement is because of the underestimated speed of the storm, the strengh of the subtropical ridge, and the speed and strengh of the trough in the United States. Most models have begun the Northwest/North turn to early and hence since then, most of them have trended at least some west, for example 12z Nogaps, and 12z ECM are not far from the coast, take them for granted. As of right now, this is not just forecasting time, this is nowcasting time too, observing the storm, wind speed, track, and location.

I am forecasting this WNW/NW direction to last for 24-48 more hours before we turn more northward, I am expecting this to get as far west as about 70W off Cape Hatteras and then ride North/Northeast most likely affecting SNE before turning more eastward, though there is still time for this to change, this could go closer to bermuda or closer to the US coast depending on Bill's path, and the strengh and location of the subtropical ridge and trough. You can see my map above, once again the black line equals the most likely possibility.

Here is what I am predicting for the percentages of the situation.

Early Curve, Bermuda Hit or East of Bermuda:10%
Expected Time Of Curve, Between Bermuda and US, Effects in SNE:60%
Later Curve,Coastal Scraper and SNE landfall, Mid Atlantic and Northeast Affect:30%

Overall, In my opinion, most of the Mid Atlantic and Northeast should get affected by at least higher waves, I insist on folks on the Eastern Seaboard and Bermuda should watch this closely and take action if needed.

Next update will be 0z Thursday.

Comments would be appreciated.

Hurricane Bill Discussion (Ryan)

http://forums.accuweather.com/index.php?s=&showtopic=14042&view=findpost&p=553728

My Accuweather.com Forum post as the images would take very long to upload.

For other info on Hurricane Bill, visit the National Hurricane Center's Website at

http://www.nhc.noaa.gov/

Second Forecast On Bill

Over the last 36 hours, Bill has went through good strenghening, we are now at a Category 2 Hurricane.

Over the last 24 hours, I have noticed the faster than forecasted speed of bill, which is giving it more time to move Westward before the trough gets to it while a ridge stays north. This evening's steering currents are helpful of a temporary westward movement.

Now for the track, I am expecting this to move westward for potentially up to 12 hours, before it starts turning WNW, in 24-36 hours, depending on the speed of the storm and trough, should start turning NW, and then should start heading N, most likely west of Bermuda, and then should move back out to sea. The reason I am using should is that if ths storm can move fast and south enough, this MAY go through the carribean area and into the GOM potentially. The strength of this should max out at category 3/4 strength. I have revised my map which you can see above, black line equals the best chance for a track in my opinion.

Here is the percentages for the situations.

Out to sea, east of Bermuda:5%

Between Bermuda and America:50%

East Coast Landfall/Effect:30%

Gulf Of Mexico:15%

As of right now, everyone from Florida to Maine should watch this one closely in the next coming days.

Comments would be appreciated.

Tropical Outlook (Bill)

Hi, it is Ryan with an update on Hurricane Bill.

As of 5PM AST
Winds: 90mph
Gusts: 105mph
Minimum Central Pressure: 969mb
Movement: WNW 16mph

I will have other info if any land is threatened.

I think the models are surely trending west. The weakness as mentioned was overestimated. The trough is quite deep in the GL and the trough axis, which with the 18z had the neutral at 108 to the slightest bit negative to me at 126. I am a good bit confident that the trough is not negative enough and therefore deep enough to prevent a strong shunting and recurve of the storm like TWC and the NHC are predicting somewhat. I think anyone from Cape Hatteras to Nova Scotia needs to keep their eyes peeled on this storm.

My software isn't working so I don't have the images. Computer=suckish right now.

Check for more updates by Chris, Nick, and/or me at mdwx.