psuhoffman

Geps as predicted lost that weird split wave look. Back to looking like other guidance. It’s south of the gefs and significantly weaker though. But at least it’s back to the right progression. Targets central VA.

Stop judging runs by snow maps. Cmc was an improvement.

@Ralph Wiggum dug this up...that gfs track and intensity was pretty identical to a previous storm with similar strong blocking. This doesn’t have the same upside because it’s moving faster and doesn’t have the same stj juice but this gives an idea of what the precip representation for a storm of that amplitude and that track should look like. Some differences. The primary was a little stronger to the west initially and after that point above the Feb 2010 storm gained SLIGHTY more latitude but by then it was occluding and the precip was sinking southeast anyways. I would obviously scale back the qpf a lot here and I would shift the northern fringe south maybe 20 miles. But just saying if that gfs track and intensity was correct the results into southern PA would be a lot better. But there would be a brick wall somewhere not far north of Philly.

Typical model error. You know how this works. There is never that slow gradual tapering like that. The guidance never sees that enhanced lift area on the north fringe banked up against the confluence to the north. Happens time and again. If this run was correct wrt surface and h5 track and intensity this would be the real result. Somewhere near that red like would be a sharp cutoff with south of that line getting more then what is depicted there and closer to the Max down in VA.

here we go again down the next rabbit hole. Why not. So this time the TPV is actually on our side and the coldest air in the N Hemisphere is in N America. -NAO. WPO ridge. Cooler SSTs in Feb. Ok might as well try EVERY possible variation of a good pattern just to prove we’re fooked no matter what lol

Don’t ask questions you won’t like the answer too.

If we’re really gonna do this...the tpv is in a better spot on the NAM then the gfs even. It’s south but west. Get that far enough west and it could end up pulling this north more. But that’s playing with fire (literally with our base state) so let’s not go there. The h5 is more amplified but it’s also a bit spread out with a southern and northern max. That’s not so good. I wouldn’t worry about the surface wave escaping that’s likely 84 hour NAM foolishness. Besides the primary will amplify in the TN valley in response to the upper feature then the secondary will form in response to that. Even if the initial wave escapes it might not matter.

My thoughts on the 84 hour NAM are that it’s the 84 hour Nam.

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