Monday, September 28, 2009
Saturday, September 26, 2009
October 2009 Forecast/Discussion
October 2009 Forecast/Discussion
Temperature
Precipitation
Pattern
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.
Monday, September 21, 2009
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!
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!
Monday, September 14, 2009
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.
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.
Saturday, September 12, 2009
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.
Tuesday, September 8, 2009
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.
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.
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
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.
Monday, September 7, 2009
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.
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.
Sunday, September 6, 2009
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.
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
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
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.
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.
Thursday, September 3, 2009
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.
Wednesday, September 2, 2009
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.
Tuesday, September 1, 2009
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.
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