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.