CAPE

Looking over the latest ensemble runs for the Friday-Saturday deal.. the GEFS took a major step towards the Euro/EPS and CMC ens in emphasizing a primary low tracking into the OV and NW of our region. Something to watch(and maybe the best chance for frozen with this event the way things look right now) is a developing coastal low later Saturday as the colder air comes in. Hard to tell on the ensembles if this is due to trailing energy on the front, or a low developing offshore of the coast in response lowering h5 heights as the main trough approaches. Probably the latter. The ops are pretty messy looking with the vorticity at h5, and it will change, so not worth further analysis at this time, at least from me lol.

It's all relative but we had some decent cold this winter, mostly in January. Last winter I never recorded a temp below 20, even during Feb with snow/sleet otg and clear skies at night. I had at least 2 single digit lows this winter following the 2 bigger snow events- a low of 7 and 3. Also managed to keep snow otg for longer stretches. Part of the reason we didn't get any super cold air is the progressive nature of the pattern, which you touched on. The legit cold we did get was a 2-3 day shot then quickly modifying as the trough departed, then rinse and repeat. The longwave pattern never stayed aligned long enough to get cold air in place, and then reinforcing shots of cold. We typically need help up top for that. Even though the ens means sometimes suggested it, we never had anything close to a 2014 type delivery of true arctic air, and definitely not with any persistence.

Low of 29 here. Bring on the 60s! 70s! 80?

For the midweek potential system, we get some colder air working in behind the early week rainstorm as a piece of NS energy slides across to our north. This flattens the ridge and sets the stage for a wave to move along the boundary just to the south. Right now it looks fairly modest, and the northern/western areas of our region would be favored for some wet snow. GFS/GEFS is further south with the wave than the Euro/CMC and their ensemble means.

There are pretty big differences between the GEFS and EPS wrt the trough position at the end of next week, and thus why the EPS has the primary low pressure tracking inland/NW of our region, while the GFS/GEFS emphasizes more of a coastal low tracking along/offshore of the coast. The latter would be the colder solution and be more conducive for frozen. The Canadians side more with the Europeans at this juncture. This may again be another case of the GFS being too aggressive with advancing colder air masses at range.

Possibly. During the January period when we had some good cold available, the pattern was progressive(minimal to no blocking) so it all came down to timing, and it happened to work out for places further east with later developing coastal lows. I would argue that it was not really a true STJ though- we had a bit of a split flow at times, but the amplified pattern allowed shortwaves entering near AK to dig further southward than is typical, so in some cases those became our 'southern' waves.

Be careful with that association. Ninas can feature blocking, but they almost never have a persistent/prominent stj. That feature is characteristic of a Nino and allows for storm development further south/SW so as to have greater impacts at our latitude, in conjunction with HL blocking(encourages storms to track underneath and keeps cold locked in).

Canadian ens looks much more like the EPS than the GEFS. Who wants to ride the colder GFS/GEFS look at range?

12z EPS isn't any better. It tracks everything to our NW then brings the cold in next Sunday, so we get mild and wet followed by a couple days of transient cold and dry. The higher elevations of western VA/WV/W MD would probably see some frozen during the Thursday-Sunday period verbatim.

I'm skeptical of that period being cold enough at this point. Possible, but not sure how cold we can actually get in the Wed-Thursday timeframe. It will definitely feel cold after the prior few days though.

Still a lot of spread among the members but the potential for a 'go big or go home' type storm looks to be next weekend.

The initial wave on the GEFS-

Yes, kinda.

The general setup for late next week would certainly favor inland areas at elevation for potential frozen. Ji might be more interested if he wasn't stuck in eastern Loudoun county.

For next week, there are some differences between the EPS and GEFS wrt any colder air initially moving into the region- mostly associated with the timing and exact location of the pieces of energy being shed off the TPV and rotating down. The GEFS suggests a wave mid week with the boundary close to us, thus some potential for a little frozen. EPS has that wave but a little later and a bit warmer. On the heels of that the main trough approaches and there is the potential for a bigger storm heading into next weekend. For now it looks like there will be an initial LP tracking into the OV with a coastal low developing. Way too soon to discuss details, but this is the look on the latest GEFS-

Yeah it's been mentioned a time or 2 .

3 straight days of 60-75.

We can do cold and dry here in March lol. Hopefully the advertised cold period is legit and we can time something up. There certainly have been hints on the ensembles, but we are talking the 10th at the earliest and likely beyond, so no consistent signal yet.

Yeah that is a radical looking flow path lol.

I tend to agree, but there has been a recent trend on the ensembles to shift the mean trough eastward sooner. The eastern US ridge in the h5 panel I posted is pretty flat and eastward compared to a few runs ago.

This is a pretty interesting look on the latest EPS. The window around the 10th is probably the earliest shot at something other than rain, but it has looked a bit too warm on the means. Latest trends have a deeper trough around the Aleutians/more ridging along the west coast, a more southward displaced TPV, and quicker progression of the trough into the central/eastern US. Probably still not cold enough verbatim here, but this would be an east coast storm with a track along the coast or just inland.

Oh damn lol. Well, it's certainly not the most 'intellectual' of games.

High of 58 here.

Looks like a couple days of low to mid 70s. Sunday might be the warmer day. I need to get that skeeter larvicide ordered.