winter storm watch for DCA,BWI. Could be extended later....

[WXBUFFJIM]

Good afternoon everyone. A very complicated weather scenario over the next few days. A warm air advection pattern will take hold Thursday afternoon and night. As warm air overrides the colder air at the surface courtesy of high pressure to the north, any precipitation is more than likely going to be frozen for many locations from western North Carolina up through western and central Virginia and into western and central Maryland and mainly in the form of sleet and freezing rain. western North Carolina up through west central Maryland are under winter storm watches. However parts of western North Carolina have winter storm warnings and winter weather advisories out at this time due to ice and a potential for an icestorm tomorrow morning and beyond. Keep an eye on this from Ashville through Greenville. A potentially dangerous time on I 85. The triadd, the triangle region is looking really bad. This comes on the heels of a pretty bad icestorm back in early December of last year for this region. No watches or warnings are in effect further north into Pennsylvania (YET) I emphasize the word yet because watches will likely be required that far north as well. Definitely keep an eye on this from Pittsburgh all the way over to Philadelphia because you guys will likely get quite a beating from this storm with a snow and ice mixture. It's hard to pinpoint exact amounts. However this is forecast to be a long duration storm system that lasts through Saturday. As surface low pressure develops off the eastern seaboard Friday morning, even more cold air will be advected south into the mid atlantic region. Meanwhile a strong upper level disturbance will catch up to this storm with the core of the upper low situated over Virginia and western North Carolina by late Friday night into Saturday. As a result, not all layers of the atmopshere will be below freezing. So while snow will be the main precipitation type Friday night into Saturday north and west of Philly, DC, and Baltimore, once again the big concern is ice from the cities of Washington DC, Baltimore, and Philadelphia too. Some places could see both a significant snow and ice accumulation potential, especially from the big cities north and west. Meanwhile the eastern shore of Maryland and Virginia will likely see a mainly wet pattern with a mixture of rain and wintry precip at times. However the rain on the eastern shore could change to frozen precip in portions of the eastern shore, especially Friday night into Saturday as colder air moves into place.

As you folks can tell, this is a complicated weather scenario because DC through Philly are in the rain/snow line and mostly a potential icestorm. The bigger snow amounts maybe north and west of the big cities. Places such as Hagerstown, Pittsburgh, Harrisburg, and Allentown will likely see the higher amounts of snow with a significant ice event potential south and east of that. This is a situation we need to watch very carefully and I will continue to monitor this throughout the next day as it evolves. Stay tuned.

Jim

[JCT777]

Thanks for the update Jim. A model consensus by noon tomorrow would be nice. I hope we get one.

[WEATHER53]

These ideas are becoming more and mroe reliant on a phasing job coastal low which historically cause big misses for DCA, points north of Philadelphia often get hammered but phase jobs do not wrok around here.

[Colin]

What do you think about my region Jim?

[Anonymous]

This is Jeb not Jim lol

Colin, I think you will see more snow than ice, probably to the tune of 3 to 7 inches.


-SnowBlitzJEB

[Colin]

I think much more than that my friend...

[WXBUFFJIM]

That actually sounds like a good total for right now. Most of the precip may occur Thursday night through Saturday am for southern and southeastern Pennsylvania and east central PA also. If any mesoscale bands set up for a long period of time over a certain area though, enhance snowfall rates and thus higher accumulations are possible. It's still a bit too early to get exact amounts. But a half foot plus seems like a good possibility for central Pennsylvania.

Jim

[wxid]

Hey Jim , good to see ya here for this years first 'round these parts! I think you and Wx53 might have a little fun w/ this one, as for my area (SBY, MD) it looks like the usual (washout). Have fun!
Wxid

[WXBUFFJIM]

If you're headed to ocean City this weekend, the seas will be very rough in the 10-15 foot range. It could reach 20 feet beyond the surf zone Saturday afternoon with sustained winds near 50 mph with gusts to 60. This will have alot of wind with it and with the full moon approaching, we need to concern ourselves with tidal surge and flooding on the barrier islands with this strong gale center coming up this weekend. There won't only be a wintry aspect to it. But a coastal threat is very high.

Jim

[Colin]

That actually sounds like a good total for right now. Most of the precip may occur Thursday night through Saturday am for southern and southeastern Pennsylvania and east central PA also. If any mesoscale bands set up for a long period of time over a certain area though, enhance snowfall rates and thus higher accumulations are possible. It's still a bit too early to get exact amounts. But a half foot plus seems like a good possibility for central Pennsylvania.

Jim

3-7"? Now that's funny...