psuhoffman

Just for fun... but until guidance gets a better handle on this I wouldn't trust any op run. The idea of a storm there (where CAPE targeted) is just coming into focus now. Long range suddenly looks really interesting again.

A 1" change in an op run at a specific location is noise. The Euro has been showing the same general idea for many runs now.

Sun is hot

IMO the euro would have been a very good run...except the DC area kind of got stuck in between bands. A really nice initial wave went to the south in the early morning and then the second wave went just to the north. It's possible it goes down that way...or that initial wave holds together more and you don't see that dead zone in between with 1-2" less. I don't trust any of the guidance to nail that kind of detail even at 24 hours.

It CAN happen...just very rare but March 1960 Winchester recorded 11", 5", and 7.5" of snow in March and had 9 straight days with a high below freezing AND didn't reach 40 degrees for the first time in the month until March 17th! There was snowcover until March 22nd. That is the most extreme stretch of snow/cold we have ever seen in March but history says it is possible.

March with a -40 SOI argues against dry lol BTW...the GEFS actually supports the extreme op solutions, at least in terms of the general pattern. Holy Cow look at that TPV displacement... this would certainly load the baroclinicity across the CONUS in March! I could see some more wild op runs incoming if this is the general look we're dealing with.

This GFS run really drops the hammer in early March. The overall look with that TPV displaced south into Canada certainly opens the door to something like that. That run was just extreme though.

This isn't "brutal" enough for you... in March LOL It's actually about the weeniest long range you will ever see in March. A 10" plus area wide snowstorm with temps in the low 20's during the storm. Then 3 days of brutal cold with lows around 0 and highs in the teens and low 20's and then a second big storm incoming at the end. Obviously this is all just fun but if we could just lock that up seriously!!!

@C.A.P.E. I am obviously having some fun and kidding around.... but I do think the long range looks hold real potential. But anything past day 10 this year is a complete pipe dream so we're not even close to start taking specific threats seriously yet. But if...super duper if, the general h5 pattern being hinted at is legit we probably will end up tracking something in March.

I changed my mind...I want that next one too. What can I say I'm greedy when it comes to snow.

Or this... INCOMING!!! LOL

PLEASE just this one.... then I will gladly welcome spring!

Some interesting dates keep showing up in the super-ensemble analog guidance 11. Feb 1993 and March 1993 March 1984 March 1965

guidance finally picking up on this? It's obvious the SE ridge and the TNH pattern is resisting the full impacts of a nino phase 8/1/2 which would typically go to full on NAO blocking and a deep eastern trough. The look now is more of a hybrid between a +TNH pattern and a nino MJO phase 8/1/2. The key to that compromise working is to get just enough ridge over the top to suppress the boundary south of us. Then we can either hit a wave like 2014 or 2015...or if we want to go for broke hope for the 1993 type of thing with something rotating down around the PV and bombing. It doesn't have to be to the extreme of 1993 (and very likely wouldn't be) to work.

It's really hard to use the GFS in these situations because its lack of resolution really forces you to assume a lot about the details. But the GFS blasts our area with some heavy precip between 11am and 3pm. At 18z the column is still cold enough for snow across northern MD...barely. By 0z its toast. But how long it can hold on with mixing of the warm layer with those heavy rates would determine our fate. If we can hold on an extra hour or two during that band (not a crazy idea given the typical mixing and dynamic cooling in such bands) the GFS implies a really good thump up here. @HighStakes It totally depends on the banding. Think of the similar events to this...Feb 2007 (NOT the VD storm the second one), December 2013, Feb 2015 had some similarities too... the area's that get under the heavy bands will hold the column longer. The VV's and heavy precip will help to mix out the mid level warm layer from WAA for a time. If we get under that banding we will get thumped. If we don't...the mid level warmth will race north and its congrats PA. We know the drill. I have no idea where that banding will set up. No one does. We can all make educated guesses. But the idea of a duel max is gaining some traction imo today. Even the guidance that hits our area pretty good "sees" the banding associated with the jet streak up over PA its just not killing the STJ WAA moisture plume into our area as much and is hitting that band up there less. Figuring out those kind of details are above my pay grade though. So my goalposts from 2 days ago are still in the same place LOL... Notice even the guidance that thumps us still has some enhancement up in central PA associated with the jet streak? Its just the NAM is going nuts with that and killing the WAA/STJ moisture feed south of it. The other guidance has more of a duel max idea hinted at between those two areas. That is a much better result for us.

I don't think its as drastically different as it seems looking at DCA as a specific spot. GFS lacks the resolution to nail exact placement of banding OR correctly factor in mixing and other dynamic influences of that banding....and it sucks with surface tamps from CAD. So you can only get a general idea from it, details are useless. It just misses DC by a few miles with two different bands...just south early and just northwest later and so that specific spot lost snow... plus it warmed SLIGHTLY which hurt a lot in a marginal setup. NOT saying the GFS didn't degrade a little but if you step back and look at the temps and precip over the period it wasnt some huge shift just a couple very minor shifts that bumped DC in the wrong direction in what was a marginal setup to begin with wrt heavy snow totals.

Rgem still targets DC with best banding.

ICON is another beatdown across the area... kind of has the euro idea of two heavy bands but is even thumpier with both... first band crushes DC and northern VA early morning...second band crushes MD late morning to mid-day. Everyone wins.

NWS must be weighting the GFS/FV3 a LOT in its forecast... only way those bullish numbers make a lot of sense.

It has actually been pretty consistently north for 2 days...it had that one great 0z run that went south and NAMd DC and MD and got everyone excited...but it had been north before that and went right back at 6z and has only been shifting further north every run since. Everything else has kind of been shifting north (except the euro which has been rock solid steady) also...but is still way way south of the NAM. Interesting model war. Unfortunately this is kind of the exact situation the NAM was designed for. Still doesn't make it right. I suppose the high res Canadian SHOULD be able to handle this kind of thing also.

THIS THIS THIS... people need to focus on where the best banding sets up. It's that simple. We have seen this type setup over and over. Wherever those intense bands set up during the mid morning to mid-day will delay the flip to sleet as the intense rates and vv's will help to mix out the warm layers for a time. That extra 2 hours (along with a LOT of qpf in those 2 hours) makes all the difference. The guidance can't agree on where that banding sets up. Euro kind of splits into two areas...one south of DC early and one north of DC later. GFS and RGEM like to crush DC. ICON and HRDRPS likes MD. NAM is way up over PA. But that banding feature is the key to who gets good snow and where is left kind of disappointed by all this imo.

It's not dry...its just shifting the best forcing NORTHWEST of us...its aiming that stj moisture plume across PA instead of our area. Lets see what the other guidance does today before deciding were in trouble. IF...if if if...everything else moves towards the NAM then I agree we are in trouble if people expect the 4"+ snowfall totals around here. But as of last night the NAM was pretty much on its own with that look. Sometimes the NAM is onto something...and often the NAM is just off on a tangent smoking some bad mojo.

The issue with the NAM's are where they set up the best banding. They push the best fronto banding north of our area. Even north of my area. After an initial short thump around 7am it focuses the best banding up in PA. You can see the cooling from the heavy band in the morning at 700 mp and then once that lifts north with only lighter rates the WAA takes over and without heavy rates to mix the column we torch at the mid levels. That is how this works. If we stay under heavy banding like the GFS/FV3/GEM/RGEM/HRDRPS/ICON suggest the flip will be delayed a couple hours plus combined with more qpf and we get those 4-8" numbers NWS is pimping. But if the NAM's are right that the best lift and banding ends up to our north in PA, this will be very disappointing to most in here IMO. I am NOT saying I think the NAM is right here...but the NAM progression of this would be a quick 1-3" followed by ice across most of our area. That would probably be considered a fail by most in here considering what the official NWS forecast is right now!

All of the snow in DC and northern VA comes with that initial wave between 5am and 11am. On the euro at least.