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Winter Storm Threat: February 26-27 (Only/Final Call)

It’s time for the southern folks to finally cash in this season. Some spots in North Carolina and southeastern Virginia are expected to get as much snow as they typically get in a year, so this should be a fun storm for them. I battled a bit in the placement of the 1″ and 2″ contours on the north edge of things, as there is a wide range of solutions in that department still. The rain/snow line across North Carolina is another big hurdle, but it seems the warm nose will be around 850mb, which made sorting it out on the models easier.

20150226-27_MAsnow_final

I expect a couple of 12+” reports out of this in North Carolina and southeastern Virginia. The northern edge of the 1-2+” has equal risks of busting high/low.

Winter Storm Threat: January 25-27 (Only/Final Call)

Not going to go into details because I have spent way too much time looking at this storm between work and home. Also, I’m prepping for a snow chase in New Jersey, so that has taken up much of my afternoon.

20150125-27_MAsnow_final

A bit more conservative than the Euro and NWS overall. The lack of support of big totals from some of the other models in the Mid-Atlantic gave me pause. There’s a lot of moving parts to this system, so it’s really anyone’s game still. I just hope I’m not terribly wrong.

Winter Storm Threat: Nov 26-27 (Only/Final Call)

We have quite the complicated winter storm on our hands for tonight through tomorrow, with some snow/mixed precipitation expected on the leading edge of the system that will change over to rain in many areas before the back edge transitions over to snow. Accumulations of 1″+ are mostly reserved for the mountains where the back-end snow will last long enough for such accumulations, with the westernmost areas expected to be all snow. Snow and mixed precipitation at the start of the event tomorrow morning is difficult to assess in both the start time and duration before it changes over to rain, and will generally be west of (and maybe a little east of) I-95. Isentropic lift will battle against dry air in the lower levels at the onset early tomorrow morning, with steadier precipitation moving in between mid-morning and mid-afternoon across most of the region.

If temperatures are cooler at the onset of precipitation, snowfall may be able to get to 1″ east of the forecast line before changing over to rain. Widespread rainfall of 1-3″+ is expected along/east of the Appalachians as this system moves through tomorrow afternoon through Wednesday before the back edge switches over to snow. The wet, saturated ground could hurt snow totals on the back edge of this system unless the snowfall rates are good enough to overcome this obstacle.

Winter Storm Threat: Dec 26-27 (only/final call)

Forecast confidence is low as most of the snow falls at the front end of the system before many areas switch over to mixed precipitation and/or rain. Very small changes in temperature at various levels of the atmosphere could lead to significantly different snowfall totals, especially east of the mountains. The northwestern parts of the forecast region could/should stay all snow throughout the event, which roughly matches up with the 8-12+ inch area along and west of the mountains.

There will be some lingering snow in the central Appalachians at the end of the event as cold, northwesterly flow takes over.

Winter Storm Threat: Nov 27 (only/final call)

This storm will drop a rain/snow mix south of the 1 inch line, with a slushy coating possible across northern MD into Philadelphia. Higher elevations will do better with this event, especially from southern PA southward.

A rather weak disturbance will slide across the region tonight into tomorrow, bringing wintry precipitation to the region from DC northward. South of DC will be mostly (or all) rain, with a rogue snowflake or two possibly mixing in with the rain, especially if the precipitation rates are high. Temperatures are cool enough aloft for snow, but the low-level temperatures are forecast to be above freezing up through southern PA, which will keep accumulations limited on the southern edges. If low-level temperatures hold warmer than expected, snow totals will be lower than forecast.

Severe weather possible in the Mid-Atlantic tonight/tomorrow

The synoptic setup is somewhat favorable for damaging winds and perhaps an isolated tornado or two tonight into early tomorrow in the southern Mid-Atlantic as storms ahead of a cold front push through the region. Poor lapse rates will likely prevent severe weather from occurring in DC, Baltimore and points north and west.

The storm system will be what we typically see for severe weather setups in the Mid-Atlantic during the winter and early spring… low CAPE/high shear. This system was looking fairly marginal for the region up to this morning due to the poor mid-level lapse rates, but it appears that the previously under-forecast dynamics will help introduce better lapse rates to the southern Mid-Atlantic. It is still fairly borderline, but with a strengthening low-level jet producing 50-60 kt. winds at 925mb it wouldn’t take much to bring those damaging winds to the surface.

925mb winds at 4am:

Forecast sounding for Richmond at 4am:

The sounding shows that there is enough directional shear for the anticipated storms to produce a tornado or two in the southern Mid-Atlantic tonight into tomorrow morning.

SPC’s outlooks for tonight into tomorrow morning:

I am mostly in agreement with them, but I would tone it down to a SEE TEXT instead of a Slight Risk north of the NC/VA border as the storms don’t look to be terribly organized, which is something you want to see for a Mid-Atlantic low CAPE/high shear system (at least for the damaging wind potential).

Hurricane Irene Video

I finally got around to going through all of my Hurricane Irene footage and I put six minutes of it together in a nice summary video:

The video’s description:

Chronological video clips of Hurricane Irene from 26-27 August 2011.

Locations filmed in order (all in NC): Rt. 70, Atlantic Beach, Morehead City, Beaufort, Rt. 70 (again), Rt. 17, Rt. 64 and Columbia.

Video start time is approx. 5:30pm on the 26th and runs through about 1:30pm on the 27th. Tornado damage at the end of the video was along Rt. 64 just 1-2 miles east of the center of Columbia.

I chased with Jason Foster. This was my 1st hurricane chase, and it was Jason’s 8th.

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