MillvilleWx

The Euro would be an incredible storm for all the sub-forum west of the bay. There is going to be a huge thump of snow before any changeover if the current 5H and SLP setup hold. A jog further east with the SLP and you'll be looking at an all-timer around these parts. Still so many details to go through. A storm is very much on the table now.

He's already looking at the one behind this one

Correct. Also, the GFS is not a good model with handling a sharp transition zone with storms like this. It erodes the PBL too easy, then goes way off the rails near the surface. The antecedent airmass leading in is fresh and very cold. That's another reason why a setup like this would yield a thump of snow before a transition. This is a dynamic system if it evolves as depicted.

Absolutely agree with this assessment. The 5H look SCREAMS a huge thump of snow before any switch over. There is one part to keep an eye on and its the positioning of the high pressure to the north. A spot like the CMC would allow for u-vector winds to be off the charts and usher in maritime air within the 850-925mb layer of the PBL. That would change things to sleet EASY, but not before a nuking occurs with snow. The further NW you are, the better in this setup. This is actually a great system for an area like Hagerstown/Martinsburg/Winchester crew.

Short Pump forecasts go here

Not strength, but track!!! haha This ain't even in the same zip code in terms of strength. I do like Chaos though

SLP was super jumpy too. The 5H progression was actually pretty solid, but the SLP was west of where it should be. You can see the jumpiness of the low when you walk through from 00z Monday, onward. Should take a 1993 Superstorm track, not a track over DC. Split hairs with a track over even CAPE's hood would be a big difference.

Looking at soundings, I would see this more of an IP than a rain situation outside of south of Rt 50 and east of the Bay. GFS scouring the airmass so fast in the lowest confines of the boundary. Also, the wet bulb aspect of the forecast is bizarre. GFS brings the dew point up to the temperature with no drop in the temp within a 3 hr window. Would call complete BS on that as well. That track has yielded IP plenty of times. ULL is also cold as hell with it dropping to 528dm over Wakefield and 525dm over Dover. Color me skeptical of the reach of pure liquid. 850mb jet is screaming, so a transition would be all but probable, but the pure change to rain probably wouldn't be as likely west of the fall line.

Obviously a track like that from the SLP would yield a transition period from snow to IP/ZR, but it was still a very good 5H setup for a front end crush job prior to any changeover. This was a classic I-81 storm track where deformation axis would ride from RNK to HBG. The western side of the LP on the precip field was a little wonky for such a dynamic system. I would see it more defined than what the GFS had. Regardless, the prospects of some snow are definitely on the table. Favored areas probably west of I-95 with most favorable west of Rt 15. Long way to go. No where near settled and big swings are certainly possible.

Man, the GEFS and EPS are absolutely all in on extended winter for these parts. GFS deterministic showed a textbook cold outbreak signature for much of the CONUS. GEFS supports a long lasting cold signature. Winter is coming guys, buckle up!

Good morning y'all. Looking at guidance this morning, it's pretty prudent to lead with this potential setup is riddled with fine details and the probability that we are at the final solution is extremely low. In order for the sub-forum to get what the GFS just advertised, you need everything right in terms of 5H spacing, phasing timing, and thermodynamic structure to yield a scenario like that. Absolutely in no way am I saying it can't happen like that. The major storms, especially the historic storms all have that occur, but this isn't a split phased bomb where a southern jet gets merged with a NS vort. This is very much a deep digger, translating into a Miller B bomb that could climb the coast due to increased spacing between the TPV over Quebec and the second s/w progressing through the northern plains at the same time our storm is going off. Timing timing timing. It is everything with this setup, but there is absolutely an environment available for something truly special. We haven't even gotten into the fine details of frontogenic forcing, jet stream dynamics, complexities of LLJ structure and positioning. The big ones are special for a reason, so keep a level head and don't swing hard on each run. That's Ji's job

Facts Facts Facts

That's the best news you guys could ever ask for

Color me skeptical, but give me the under on Wake Forest, NC at 24" haha I will say the Carolina's certainly need to keep an eye on this one. Everything, no matter the setup seems to drill them. The sub-forum I believe did gain life with that run. It was a wild swing, that's for sure. I want to see the ensemble guidance.

That is a crazy step towards a MECS up into the sub-forum lat. Still a bit off, but the delay in s/w out west was beginning to allow enough time for the TPV over Quebec to move out and provide spacing for northward movement. A crazy shift in the setup for this run. It opens the door for a lot of possibilities, but we still need more confirmation from the ensembles to see if this COULD be a trend, or a blip on the radar. Verbatim, it's a potentially historic storm for NC and Upstate SC. Absolutely insane for them

Just a wee bit different I would say. This is going to be a whiplash week me thinks....

Yeah. Much slower at that. NAM might just being NAM things. It tends to do that at range, so I wouldn't even consider it unless there's a trend with other guidance. Then I'd raise the eyebrows.

But.....it nailed the NW extent of the 2016 Blizzard!!! Blind squirrels, nuts, and something something 2000....

The difference in the s/w position between hr 78 on the 00z and 84 on the 18z run is just slightly different. What's 200 miles between friends eh?

Sir, I'm gonna have to ask you to leave the forum for a timeout and think about what you did. Don't come out of your room until you feel sorry for what you did!!

That's the one! That thing laid a nice fresh powder from the Alleghany front to the bay. All of northern MD got hit pretty good. I couldn't believe my eyes when I peered out the window that morning. It was still snowing. NWS had to be playing serious catchup. No one was even in an Advisory. They almost had warning criteria near the MD line.

There was one back in 2003 that hit out of nowhere I remember. The forecast was light snow possible with less than 1" expected. Woke up at 545am to a WWA and 3" of snow with a 2 hr delay for school. That winter just snowed anytime it wanted to. Eric basically drooled on his tweets this AM lol

It's a Carolina mauler on this run, but heights over the NE are higher. GFS still favoring a SE US strike. A crazy powerful s/w trough that drops out of Manitoba.

I know some people are interested in instant satisfaction with the coming pattern, but this is one where Mother Nature is loading her shotgun with buck shot and not a slug. There’s gonna be waves zipping through the pattern like cars on the Capital Beltway at 700pm on a Friday. It’s a pattern that will have the chance to yield both smaller events and big kahuna’s. There’s gonna be a monster in this setup for somewhere in the east. With so many distinct 5H vorts parading through the flow, that storm is unlikely to be captured at long leads. Take a break from model watching and browse every so often. It’s going to be headfake city until the N HEMI pattern is fully established in a week. I would be shocked if the Mid Atlantic came away with nothing, but even some small events can make the area feel wintry.

I'm a giant stat nerd myself, so I understand. Idk how my wife puts up with me There's a ton of intricacies within the NWS on things, so we get some questions all the time. Sometimes those questions make us question our sanity, but we still answer to the best of our ability! This one is super tame comparatively haha