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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: November 26 (Final Call)

Well, the model trends over the last 24 hours were not in the direction I though they were going to go, so I had to cut back the forecast along I-95 and make some smaller adjustments on the western edges of the contours. Overall, things have shifted slightly warmer across much of northern VA, DC, MD, NJ and southeastern PA in areas near and west of I-95. With such marginal temperatures of 33-36F at the surface, snowfall rates will be the big thing to watch tomorrow to see who will cash in and who will get stuck with little or nothing. Sloppy, wet snow for the major population centers along and near I-95.

20141126_MAsnow_final

The difference between 4 inches and 8 inches within that contour range will be elevation. Lower elevations can expect totals closer to 4-6 inches, with the higher elevations getting more into the 6-8 inch range. Along the Blue Ridge and Central Appalachians, a few of the higher peaks could hit 8+ inches. I didn’t include it on the map, but I wouldn’t be that surprised if there was one or two reports of 8+ inches in the highest elevations of north-central MD.

Some of the models even show some sleet mixing in, mostly from far northeastern MD into southeastern PA and NJ. That may actually be a blessing in disguise, as sleet can accumulate more easily than snow in marginal temperature situations, and a base of sleet would make it easier for any snow afterward to stick.

Forecast confidence remains on the low side, mostly with the eastern edge of the contours where the rain/snow/mix is the most problematic. A one or two degree change to the surface temperature could mean a big difference for some areas, both to the high side and the low side. There’s also still the question of where the best banding will set up, which will produce the heavier rates and increase the chance for higher accumulations for a select few. My best guess for that is just inside the eastern edge of the 4-8 inch contour up into the 8-12 inch contour.

Perhaps if we can get some big, fat dendrites cascading down along I-95, then that area could actually get a decent accumulation. However, looking at the temperature profiles, that seems pretty unlikely.

Winter Storm Threat: November 26 (Initial Call)

A hectic day before Thanksgiving is in store for many in the Mid-Atlantic and Northeast. Toughest challenges are 1) finding that crucial rain/snow line, and 2) honing in on QPF totals, especially when considering the deformation band that’s expected. It will be a heavy, wet snow that will at least initially struggle to accumulate on the roads. Expecting it to start as rain around the greater D.C. region, changing over to snow in the mid-to-late morning hours.

20141126_MAsnow_initial

Best confidence is for places 20-30 miles north+west of I-95 and points west. Western edges could shift a decent amount still from the MD/WV Panhandles into PA, depending on the storm track. There’s high bust potential in both directions along the I-95 corridor, where heavy snow rates will battle against marginal surface temperatures of 33-35 degrees.

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.

July 26, 2012 Storm Chase Pictures

Solo chase up into southeastern PA turned out alright as I got some shelf cloud pictures and saw some lightning. Probably not worth the 11 hours I spent driving (most of which was trying to find a place with a view), but I did gain some solo chasing experience since this was only my 2nd or 3rd longer chase by myself.

Here’s some stills I pulled off of my GoPro… all from the Lebanon, PA area: