psuhoffman

The loading pattern for Feb 2003 was a poleward EPO ridge COMBINED with a severely displaced monster TPV over top of us that in conjunction displaced true arctic air south. The specifics that lead to the storm was as the TPV started to exit it traversed the 50/50 region which set up possibly one of the most MONSTER 50/50's in history which compensated for what was honestly a complete crap longwave pattern otherwise. If you look at that storm its an anomaly in almost every way except it had the best 50/50 of every HECS which overcame the problems everywhere else. But those kinds of things are an extreme anomaly. Yes they will still happen. Every once in a while we will get something like that and it would still work. A year like 2014 would still work where we got an absolutely perfectly placed full latitude epo/pna ridge combined with enough of a -AO at times to displace the boundary eastward of normal in that pattern. Or Feb/March 2015 where we got a -EPO in combination with a displaced TPV in eastern Canada. Things like that will still work. And eventually we will get lucky. But those kinds of patterns have always been extremely rare and are not going to become more common just because all the other ways we snow no longer work as well. The issue I am talking about is why we can't get much snow in every other pattern that doesn't involve cross polar flow and some ridiculous anomalously displaced TPV scenario. That is never going to be a reliable common way to get snow here. That is super rare. I am not so much talking about our super huge snowfall years being affected. WHat I think is being affected more are what used to be the more common years. A year that used to be 18" is 9" now. A season that would have been 15" is 5". Stuff like that. Marginal events where we could have got a 5" wet snow storm from a less than perfect setup in a marginal airmass no longer works. And that used to be a LOT of our snow. especially in those less than perfect seasons which make up 90% of our seasons. It's also possible we lose some snow in the big years on the margins...but there would be no way to prove it and most wouldnt care that it was 43" instead of 48" in a season. But it really makes these years in between those rare perfect pattern season just god awful instead of bearable.

That plot in isolation is a bit misleading because a few of those members have a slower evolution and are going to show precip in later panels. Some precip falls in the next panel on most members...if you look at the total precip from the members and subtract what falls from wave 1, quite a few end up getting the qpf up to like .5-.6 in the DC/Balt area and those are still rain also. Yes if the storm was an absolute bomb with over 1" qpf over 12 hours it would work...but aren't we setting a high bar now? This is a matter of degrees. Of course it can still snow. In rare instances where we get cross polar flow and lucky with the track of a boundary wave...we have gotten snow as recently as last winter. And I am sure if we ever do get an absolute monster bomb storm with a perfect track in a blocking regime like 2016 or 1996 we can still get snow that way... but the problem is we are losing all the more marginal storms in a blocking regime lately. And those made up a huge portion of our snowfall historically. This reminds me of that storm in Feb 2021 where it took a perfect track and put down like .45 qpf along 95 and was just white rain and everyone said the problem was that the precip wasnt heavier. Yea that is one way to look at it...that had it been extremely heavy precip it could have cooled things another 3 degrees and accumulated....but my POV was that should have been a 3-5" snowstorm for Baltimore. There was absolutely no excuse that in early Feb with a perfect track storm, and a typical domestic airmass in place that it shouldn't have been snow. I guess that is just a matter of perspective.

No that is wave 2. There are a LOT of perfect track rainstorms in there...

Neither am I, and frankly as I indicated in my novel post to Ji...other than getting lucky with progressive waves during a -EPO regime...lately it seems impossible to get cold enough on the coastal plain to get snow most of the time no matter what the storm track is unless we have cross polar flow which isnt even a good pattern for big snowstorms. If I lived on the coastal plain I guess I would root for those epo patterns now since nothing else works at all...but I am a big game hunter...either huge storms or big historic seasons with lots of snow...and there is no way to get either of those from that kind of pattern.

@Ji the pattern isn’t the problem. The eps nailed the pattern. this was the period we’ve been watching for weeks and it still looks great from a longwave pattern pov That looks similar to a composite of our biggest March snowstorms Look at the specific threat next week Baffin Block, 50/50, trough going neutral as it approaches the TN valley, ridge in the mountain west, trough just off the west coast. That is a perfect longwave pattern for a big snowstorm here. It’s literally exactly what has lead to every big March snow. And all guidance indicated the storm will track south of us. But it’s just too warm. And don’t blame March, this same thing has happened in other months lately too. And then the excuse was to blame the pac because we didn’t have an EPO ridge dumping arctic air at us. But that isn’t actually the right longwave pattern to get snow. And I don’t know how many times I have to say that. 90% of our snow didn’t come from arctic air masses. The best longwave pattern to get big snowstorms here isn’t a very cold one! A huge epo ridge dumps arctic air but that longwave configuration promotes a ridge in the east. Big storms will cut. The only way we can snow in an epo driven pattern is to hope a bunch of weaker waves eject east pulling the boundary south and pray to get lucky and have one of those boundary waves clip us. But that is never going to be a path to either a MECS+ storm or a truly snowy 30”+ winter. Those both come from blocking patterns with marginally cold domestic air. The best we can hope for from an epo pattern is table scraps and if we get lucky maybe a median snowfall year like last winter for example. We will never get a truly big storm or big year that way! The pattern isn’t the problem. It’s just too warm. You figure out why!

The details that are different are important. On the op the 50/50 becomes displaced too far south allowing more ridging where we need confluence. That one change creates a totally different reality.

The optimists had to sleep. Also…note where people live. Some in here have a much better chance than others and that likely influences the tone of their posts.

We’ve had 2 issues lately. We’ve spent a lot of time in crap longwave patterns because of the -pdo. But when the longwave pattern has been ok we’ve had another issue, often it’s just not cold enough no matter what the pattern or storm track is. I’ve pointed out to exhaustion that the only time it gets truly cold is when we get a full latitude epo pna ridge which is an incredibly rare combo and it’s not even one that good to get a big snowstorm as it tends to be a progressive cold/dry pattern. We have a good pattern. But problem 2 is showing up again. Absent an epo ridge this is simply as cold as it can get I think and historically an epo has no correlation to our snow because a ridge there is actually the wrong longwave configuration to get a trough along the east coast. This has been a problem for a while so why the surprise?

I just got Eurod

*Baffin Block *50/50 *trough going neutral in TN valley *Ridge near Boise

We need the more amplified wave of the euro with the wave spacing of the Gfs

Just a reminder how much things can change. GFS now GFS 3 dats ago

How many options are there?

If it's in the New England thread its probably good for them...which is bad for us.

It's still the best solution, coldest, furthest south track...but only 3-5" from the 12z run today.

The combined snow probabilities through March 22 at BWI from todays 12z models 1": 68% 3": 43% 6": 19% but...for the first time all year the GEPS is the least snowy... which is ok because they have been the only ensembles that have ever been very snowy all winter and were always dead wrong...if we take a EPS/GEFS only combo the probabilities are 77%, 47%, 23%. Either way our best run of the season in terms of snowfall probabilities.

yea, I love his enthusiasm...but I think he over estimates our probabilities from NS dominant systems. There is a pretty extreme cutoff between Philly and NY where those suddenly become a LOT more favorable. We get a much lower % of our snowfall south of Philly from NS waves than they do. We are really close to each other geographically so I can forgive him for that...but we need a LOT more luck for that setup to work out than NYC does. A SS dominant wave coming at us from the west of southwest with some confluence ahead of it...that is really our only high probability snowfall scenario and its why DC gets so much less snow than NY. They have a lot more ways to win than we do.

In terms of snow probabilities we just had by far our best run of the season at 12z. I will post in a few minutes when the last few days of the EPS updates...but for the first time all year the guidance is saying it SHOULD snow at least some in the next 15 days.

I think that run was going to obliterate us had it continued another 24 hours. Oh well...doesn't matter its going to shift around a lot in 10 days...but I still love that threat. I've loved that time period based on a basic pattern evolution educated guess when it was still a month away...and now that its 10 days and coming into focus a bit...I still like it.

There is more cold than we have had with all the other garbage threats where we were praying for an absolutely perfect track...then we got one and it still was just rain lol. We will need a dynamic system and a good track obviously given the time of year. But...this euro run was showing that. Look at the flow at day 10. That upper low is going to track right across to our south. That was the solution we need.

We are tracking 2 legit threats that are about 6 and 10 days away and you post a 5 day snowfall map. Thanks.

cold doesn't exist anymore

Storm 1 storm 2 total

If you think this is a bad run…probably should stop tracking. This would be a win. The snowfall distribution is pretty aligned with % of climo also. When I say I’m optimistic I meant that we see some snow. We’re not going to make up for the whole season in the 3rd week of March lol.

Baltimore hasn’t had more than 5” in 7 years.