Update on Wednesday’s Winter Storm

The image above from the latest High Resolution Rapid Refresh (HRRR) model shows just how much moisture this storm system has to work with as heavy snow breaks out across southwestern Virginia (dark blue colors) this evening (image runs through 7pm this evening).

Classic Cold Air Damming Event Setting Up:

The models have held on to the idea that colder surface temperatures will be hard to scour out on Wednesday, suggesting a classic Cold Air Damming (CAD) event is setting up east of the Appalachians and Blue Ridge.

While the timing of when the Snow on Wednesday morning will change to Sleet and Freezing Rain Wednesday afternoon is still in question, a strong subtropical jet stream and Gulf moisture will aid in very heavy precipitation rates meaning the Snow, when it gets going on Wednesday morning will be coming down at rates of 1 to 2″ per hour!

The trickiest part of the forecast is how long does Sleet (frozen rain drops) hold on before Freezing Rain (rain that falls as liquid and freezes on contact) takes over?  If Freezing Rain ends up being the predominant precipitation type for a large portion of Wednesday afternoon through the late evening, there could be thousands without power from interstate 95, points west… something to watch very closely. I hate Freezing Rain so I’m hopeful Sleet holds on as long as possible.

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Monday Update on Season’s Second Major Winter Storm

After analyzing the forecast models for the past three hours and comparing the trends between the ensembles, operational and control “runs” of the North American Model (NAM), European, and Global Forecast System, I have decided to cut to the chase with this post and present to you my new forecast graphics that you will only find on DCstorms.com.

The first image is my first take on how much snow and sleet may accumulate before a change over to freezing rain occurs on Wednesday afternoon:


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Tricky Weekend Forecast

Accumulating Snow will now likely remain south of Fredericksburg and southern Maryland (on Saturday):

Simulated Radar Future Cast through 2am Saturday – Snow moving east out of Kentucky will likely stay well south of the D.C. Region.

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