psuhoffman

I remember at PSU in the late 90s when we had model diagnostic discussions in the weather station with Jon Nese and he didn’t trust that “new ETA model” and relied on the NGM. Then twice in a row the ETA schooled him/it and he changed his tune lol. Now I feel super old.

I was 90% snow in that event and got 10”. The bigger problem was the huge dryslot that punched all the way to central PA. But that was a result of a warm layer in the mid levels killing lift so it’s all related. Your points are correct though in general.

Let’s avoid the cause debate. It gets ugly and no one is changing anyone’s mind because nowadays everyone just dismisses things they don’t agree with anyways. So why risk upsetting people and killing relationships on here. But we have thermometers in lots of places and they aren’t all urban. We can confirm it’s getting warmer and it’s not all a result of the UHI. We don’t have to debate why or whose fault it is to talk about the effects on the weather which is what we’re all here for. The politics can go somewhere else.

Careful we’re slipping close to the part of the discussion I said we’re NOT having. But I have looked at the data and so I’ll simply answer from a purely numbers pov. Yes the UHI has made the heating and corresponding degradation of snowfall even more pronounced in urban recording stations. So yes urban centers are ahead of the curve. But non urban recording stations are warming also just not as fast. Now snowfall is tricky. Here seems to be the rub...because big ticket events due to increased potential energy due to warming, places north of a certain line or at high enough elevation are actually seeing their snowfall increase a bit but their variance also is going up. More big years and more duds. The average ends up a slight net increase. We (you and I) are literally right at the edge of that zone. Looking at coop data back to the 1800s our mean snowfall is actually up about 2” and our frequency of 10”+ events is way up but the chances of a sub 30” and sub 20” winter is also increasing. We’re getting more extremes. Places south of us without elevation are on the losing side of this equation. The slightly more frequent big storms are not offsetting the loss of snow in marginal setups. That’s logical since more of their snow was marginal temp wise to begin with. And that trend is true is non urban data points also but yes it’s more extreme in the UHI.

We could just move. God willing I’ll be in Colorado or New England ski country someday and not stressing model runs to get snow. I’ll still always do this...but it’s less stressful when you know even if this one misses there will be another and it will snow.

E/E rule?

Don’t do it y’all. The NAM always has that one run to get you excited just to make the fail hurt worse. I Don’t begrudge it, that’s the whole reason for its existence.

I noticed the same thing with the Brazilian But at least it looks good in a bikini

In 130 years DCs mean snowfall has gone from ~22” to ~14” in a very steady rate of decline. This (the fact it’s warning and snowing less) doesn’t seem debatable Imo. The cause may be but we’re not getting into THAT!

This is an anecdotal observation...I’ve not done an unbiased study or anything to confirm, but over the last few years I’ve found the geps to be unhelpful with medium range synoptic details. Often it will trend one way then jump back the next. Often when it differs from the op (in situations where the cmc op is in line with other guidance) the geps caves to the op. It just did that with the last 2 storms actually. Showed something vastly different then the operational and caved to the operational. So when the geps shows something “weird” not in line with the op OR other guidance I’ve learned to just toss it.

Correct which is why they are ahead of (or under) the downward curve but we’re all feeling it. Just not to that level...yet. But DCA isn’t totally a local fluke...ask @H2O how it’s been lately in that area.

It was a really weird solution...seemed like it focused totally on the upper low and never linked up with the STJ moisture at all...and its way different then all other guidance so I kind of tossed it as a weird run.

I think the biggest impact is it’s turning some of our already bad years into atrocious dumpster fires. A year that maybe was destined to be 9” or 11” ( bad but not god awful) before is like 5” now. DC is on the verge of having 5 winters (2011/12, 12/13, 16/17, 19/20 and 20/21???) in the last 10 that would all have qualified as a “dud of the decade” in most 10 year stretches from 1880 to 2000. That’s kinda hard to resolve as bad luck.

Dunno...you’re in a temp bind. If this amps up it likely tucks too tight for you. If it doesn’t it’s unlikely to crash the temps. You need a lucky band as the upper low passes and I can’t predict that this far out.

You’re very welcome. I’m cautiously optimistic. The setup is the best we’ve had. Just hope we didn’t chase this for 3 weeks (literally) only to have it fail to come together because of some discreet detail that’s not perfect.

eps still hanging around in that zone close enough to keep hope alive but not quite good enough to celebrate. There was some good on the 18z (more amplified wave) and some bad (more confluence to the NE and the wave was further south). The more amplified wave is numero uno though in factors we need. All the details don’t matter if that isn’t amplified. So I guess I’ll take 18z as a slight net positive even if results took a slight step back.

It’s stuck under the Rex block

Why 6” of wet snow would look a lot nicer (stick to everything) and last longer (thicker) 3” of powder sucks. Blows around and sublimates the first sunny day.

That’s the kinda thing where it’s fine it’s fine it’s fine then NOOOOO what have you done!!!! So long as it stays far enough northwest not to compress the flow in front of the upper low we’re ok. But it’s getting too close for comfort. If it stays behind the axis where we need the upper low to amplify we’re ok. But if it comes any further south and ends up ahead of the upper low it would become a killer! Guidance has been a mess with that. That feature was originally supposed to come across on top of the wave Monday. It ended up looping around and possibly in the way Thursday. Guidance could end to changing again it’s had no ability to accurately figure that thing out.

I’m sorry I do think the setup has big upside if we get lucky and everything comes together but a hecs was never really what I was thinking was the most likely outcome. I don’t think an hecs is EVER a likely outcome from range. That takes a lot of factors to all go perfectly. I was more thinking just getting a warning level event in DC which has been hard enough lately!

People make these declarations after looking at one prog. If we dig into the gefs it was a good run Imo. The majority cluster of gefs members have a track inside Hatteras and outside Norfolk then ENE. That’s perfect for our whole area from Wes on the southeast edge to southern PA on the north. The mean is skewed by a handful of extreme east/weak members. The reason for the qpf contraction was the loss of about 5 crazy inside amped members that would have been rain anyways. It’s never good to use snow maps to judge an ensemble run but for the love of god if they’re going to make any determination at least use them correctly. the loss of the snow from my area north is from the loss of those inside members that clobbered PA and still got a lot of snow along the MD PA border counties. So me and mappy north lost some (not concerned I’ll get to that later) but the core target zone that runs right through DC there was no change. It remained generally 4-7” along that axis. The southern edge trimmed north too. That’s the goalposts narrowing which is what should happen. The 24 hour 3”/6” probabilities didn’t change in the target zone. Now for our northern crew @losetoa6 @HighStakes @mappy Keep this in mind. Some members have a wonky surface depiction. They often miss the NW extend of heavy precip. That’s the actual cause of the last minute N trend most of the time. More then the track changing what typically happens is the precip shield expands. A track between Hatteras and Norfolk of an amplifying storm won’t miss us no matter what a model says at 120 hours. We also don’t get missed when DC is the snowfall bullseye on an amplifying storm. That’s not something that ever happens! Sometimes DC can get a snowstorm and we miss if the bullseye is central VA and DC is on the northern fringe of heavy banding. Some of those 1980 storms @Maestrobjwa likes to have nightmares about did that. Gave Richmond like 20” and DC 10” on the northern edge of the heavy banding and we got fringed. The late January 2010 storm fringed us but that was a southern VA Jack. But a track inside Hatteras with a DC snowfall max bullseye on guidance doesn’t fringe us. What typically really happens is once guidance picks up on the enhanced lift on the northern edge where the moisture feed banks up against the blocking confluence flow and adds in the orographic advantages and higher ratios NW of the cities ends up doing just as well if not better. So we don’t want to see a bullseye down in southern VA. But so long as we enter the home stretch with a bullseye just to our south we’re fine. Imo the 18z gefs was a great run for all of us. What I would worry about is simply that it’s wrong. That’s an obvious risk. But the run itself was what we want to see at this range. Now just got to get the euro on board.

So long as we get crushed Thursday let them have this one.

Who is not fringed again?

I’ve said my peace. It’s getting warmer that part isn’t debatable. In the past that started ugly fights over the cause and the politics behind that. I’m not getting into that.

@CAPE you are 100% that a nino would have a better outcome. But what if that better outcome was still muted? If you add a few degrees to the whole pattern in February 2010 I’m not sure that even happens. Some of those storms were barely cold enough really. Or with less baroclinicity maybe they don’t amp up into those monsters. What if instead of 75” that produces only 40” in this current base state? I am in no way saying were done with snow. We will get snow again. But it’s a matter of degrees. I’m seeing troubling signs patterns/winters that should have produced like 10-15” produce 5”. @Maestrobjwa you asked about those signs. Yes I saw them before the last few years. These are times off the top of my head I remember scratching my head and saying hmmm. There was a storm in 2007 that had a picture perfect track mid winter and a beautiful h5 pass and we got 40 degree rain. Even up here all I could manage was some slush bombs. NYC was under a warning for 4-8” but even there it ended up cold rain and some mix. Not an inch. 2013 might be the best example before this winter where I am convinced AGW caused a worse result then the pattern suggested. We wasted a -NAO a big part of that winter too! But there was a wave following a cutter that was timed perfect and track was perfect and somehow the cities got all rain. I got about 3-4” but even here it started as rain and was 32/33 at the end. That wouldn’t have been huge but it should have been a 3-5” snowstorm. Those add up when your avg is only 14/19” in dc/Balt. But what happened in early March 2013 was the biggest red flag. That freaking storm should have been a 6-10” snowstorm. The first week of March is not too late. The airmass wasn’t that bad. The storm track was perfect. Upper low over VA. And DC got rain. Yea we pick at small details like DC only got .9 qpf instead of .14 because of some convection robbing moisture transport but that’s an excuse. We shouldn’t have needed dynamic cooling that much there. Those 2 storms hit and DC has 15” instead of like 3” that year. 2016 there was a perfect track coastal rainstorm in early January and again one in Feb. add in countless minor events that could have been 1-2” and instead were nothing. I could go on and on and on but yet I see signs it’s getting progressively harder to snow going back longer then a few years. That doesn’t mean we won’t get above normal snowfall winters. But maybe 20% vs 40% of the time. And worse some of the years that were bad but we at least fought our way to some snow are close to shutouts now. Now what I don’t know is how much of the recent acceleration of that trend is a temporary pattern v perhaps a tipping point being reached. I have no idea. But it is getting harder to snow and has been incrementally for a while. The one silver lining I’ll leave is we do seem to have elevated risks of a hecs whenever it does get cold due to an increased potential energy due to warming (when we actually do get a good thermal gradient in rare cold periods). So I’m sure eventually we get a cold spell and some 20” storm and everyone forgets this for a while. Hell maybe this week if were lucky. It will snow. But it’s snowing less.