Coastal storm developing for Friday

Some excited buzz in the weather world and snow lovers{ }today as confidence is growing that a major nor'easter could hit at the end of the week. At the time of this writing, an area of low pressure is developing along the Gulf of Coast. In addition, a weaker storm in the Northwest is tracking along the northern branch of the jet stream. The two are expected to come together off the mid-atlantic coast on Friday and potentially dump as much as 20" of snow in parts of New England before the end of the weekend. That's the snow lovers version. And hey.. what about us in D.C? As often is the case, the DMV will be on the edge of the storms and due to timing, the precipitation type is iffy, at least at the start of the storm. Here's a look at the GFS forecast for Friday midday.

GFS Computer Forecast Friday Midday

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It shows a tightly wound low pressure off the Virginia Coast. And here is the European version of the storm for Friday early evening.

European Computer Forecast Friday Evening

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The models are similar in positioning and intensity, so confidence in this becoming a big impact storm for New England is growing. But for us, there is less confidence at this moment. The precipitation should arrive overnight Thursday and into the wee hours of Friday... around 2 a.m. (give or takea few). A wintery mix at onset is most likely, especially north and west of D.C. with a transition to rain later in the morning. Rainfall amounts could reach a half an inch depending on the exact time the rain starts and just how close the low develops to the coastline. The computer models are keeping us pretty warm overall with temps near the freezing mark on Friday morning, and warming into the mid to upper 40s later.{ }

Forecast Temperatures Friday Morning

The computer models tend spill out numbers that trend warmer than the usual outcome in similar situations. I think the air will cool as it moistens up before the actual precipitation falls. So I do have some concern just 30 miles or so outside of the city for dicy conditions Friday morning. The coastal storm will last through the day for our area with breezy conditions to go along with the rain. As the low travels up the coast it will have a major impact on New England. Boston will be the hardest hit city in the Megalopolis with 8-12"+ possible. Here's the forecast snowfall totals at this time from their local NWS office.{ }

Boston Snow Forecast Friday

As for totals for all the the northeast, I think this map from AccuWeather has a good handle on it.{ }

Northeast Snowfall Forecast Accuweather

Stay tuned for forecast changes on this developing storm. Confidence is medium for D.C. right now. I expect to fine tune timing and precipitation type in the coming 36 hours.

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