psuhoffman

Welcome! West based is better. East based can work but it’s less a sure thing. It’s also not static. It will shift around.

A -pna -NAO is actually a really good pattern in March. A lot of our March snows featured that look.

Let me know when to start worrying about suppression. Lol

I said WTH I’ll buy in. Why not. Aren’t we due something to break our way? There is a lot flawed with this setup but one thing we do have is legit cold ahead of it. A lot of the fails recently can be attributed to the lack of that ingredient.

It’s snow or sleet. There is a 6 hour period with extremely heavy precip from DC to the PA line and it keeps flipping back and forth and has areas of snow south of areas of sleet. Indicative of a small warm layer that might be overcome by rates. But that 6 hour period is the difference between a minor v major event wrt snow accumulations. It would be high impact either way with ice.

Cmc has some very heavy banding aimed right at DC then too. It’s very questionable if it’s snow/sleet. Flips back and forth for a few hours in the precip type plots. Nothing else updated yet.

Cmc looks to have a decent thump snow to ice event from the precip plots that updated.

Sold let’s go with that.

It has a mid level warm layer screaming in way ahead of the system. Wish I could make a good argument against that but I can’t.

The flow to our north is a little more blocked for that storm at 330. Not perfect, -NAO is east based and the 50/50 is a bit north but still there is some mechanism to suppress. This week we are relying on a dying tpv as it gets absorbed into the flow to temporarily knock down heights and create suppression. But once that feature abates there is nothing to stop it from cutting. Our only path to keeping the low to our south is of it gets suppressed enough early on to get it under us then it can lift north once to the coast. But once the influence of that tpv feature relaxes it likely will lift north pretty drastically. The trough axis is amplified pretty far west with no blocking.

Obviously this is not happening exactly this way....but it illustrates that any of those waves in the long range is a threat to get suppressed so long as we have blocking this time of year.

The dryslot part always works out. The thump though...

I haven’t missed this lately

That’s very true but it only works to a degree. First of all the gfs is awful with surface CAD so whatever warming we get from the heavier rain is likely offset by the fact the gfs is probably running a couple degrees too warm if it’s right about everything else. Also if it’s mid 20s or colder some if not most of that will freeze. It was pouring rain a few times in 1994 and accumulated ice. But the key is it was 25 not 30 degrees. Even if not all of the rain there freezes that would be a major ice event as shown Imo.

If the 50/50 is a little slower to move out, and with the NAO going negative again it could be, that could trend south.

That’s the sneaky wave I keep saying don’t sleep on.

Gefs with a not insignificant improvement for Thursday.

Op run at range. Dont care. Remember what I said yesterday about details at range. Even with the SE ridge going about as ape as I think is possible (seasonal trend says it will be less) the op gfs snows on central PA 3 times from Feb 22 on! At those ranges that’s the same as a hit. An op at those leads cannot pin down the boundary within that level of geographic detail. So long as the NAO is negative again we will have a chance for waves to get suppressed. Don’t take my word for it go back and look at the pacific in March 2018. It was PUTRID. Didn’t matter. Same in some other March cold snowy Nina’s. It’s really hard for waves to cut with a -NAO in March.

Keep an eye on that sneaky wave around the 22/23. After that don’t assume everything cuts north the end of Feb into March if the NAO does go neg again. As wavelengths shorten it gets really hard for waves to cut with a -NAO regardless of the pac pattern. It might not be a cold pattern but odds would favor some systems sliding east under the block. For places like leesburg and Winchester and up here that works even in a not truly cold pattern. Historically that has worked in the cities too. There were plenty of late season snowstorms where temps the day before were very mild in the past. But I honestly don’t know about 95 anymore. I need to see some “marginal” boundary temp setups break their way just once to believe they even still can anymore. It’s been a long time since we saw a setup like that work for DC.

It would. I see the possibility. I’m praying temps don’t surge too much during the rain Tuesday and destroy the snow pack up here. That does have some bearing on the outcome Thursday too!

We need a combo of that PV hanging around longer/stronger/further southwest plus a less amplified trough to our west. The tpv trend has been going our way. The trough ehh. That’s why we see the start of the storm trending colder but still ending up warm. If we were to see the trough less amplified and shift east some also that’s how we could get a cold storm start to finish. Keep the wave under us.

There are some positive trends. I’ve just seen and been burned so many times by this type of setup that it’s hard to get excited. But I’ll bite. Why not. I’ll join the weenie crusade.

These waves remind me a lot of the MLK weekend storm in 2019. From 7-10 days looked great because guidance had more blocking then once they realized there was no blocking the wave adjusted way north.

I’m Jedi mind tricking this storm. but seriously what do you care if I’m not on board. It’s gonna do what it’s gonna do regardless. But I have my reasons to be skeptical. 1. it’s a progressive wave with no blocking. History says those typically trend north so needed a south trend (or for the coldest model to hold with absolutely no north shift) from this range is not ideally where we want to be. 2. even on guidance that is “snowy” the track is precarious. Tonight’s euro pulled off something rare. When I see that on long range guidance I’m skeptical. That track is not typically a big snow producer here. 3. I’m not a fan of ice. It’s snow or bust. If I had any interest in ice I’d probably be more excited by this setup. This setup does have icing potential. I’m just skeptical of a significant snow. 4. the only reason I may have been on board with ice was to protect my snowpack. Snow otg is my number 1 thing. I Know you don’t care. That’s fine. But one thing I love about up here is we can keep snowcover for extended periods up here. But now that it looks like my beautiful snowpack will be wiped out by a 45 degree rainstorm Tuesday (yea I’m kinda bitter about that) it’s hard to get excited by some slop Thursday. I’m very likely to end up Friday with way less on the ground then I have now. So it’s a net negative!

I don’t think you did anything wrong but that was a little hard to watch.