psuhoffman

You would have NO idea there would be a wave anywhere along along the east coast producing a snow threat somewhere between NC and PA Thursday from 10 days away without using NWP. There is no way to extrapolate that far out using old school methods. It’s a miracle of science we saw this threat along the east coast from day 15!!! You’re using an example of a success as if it’s a failure!

Dude put up or shut up. All you do is complain yet I NEVER see you make a prediction on anything past a couple days. And frankly over the years your short range predictions based on the pressure in Pittsburg aren’t any more reliable then what the NWS has going using NWP along with classical methodology. Earlier this winter your method was completely useless and I had to explain to you that the lack of a “suppressive high” had absolutely nothing to do with why the storm was suppressed because it was the compressed flow in the Atlantic. The pressure was irrelevant. If you can predict the long range better without technology please show us. If you can’t then these bitter “old man yelling get off my lawn” posts are way past amusing. Oh and save us your “how dare you respond to me in a public thread” crap too.

It seems anecdotally that spread has decreased days 5-10 on ensembles on both the gfs and euro. They almost always agree with the op now. That is less helpful Imo.

Don’t confuse user error with tool error. That poster has no clue how to use nwp. The purpose of ensembles is to tell us what a reasonable range of variability is according to THAT models physical interpretation. So they can tell us if a situation is highly volition by spread. Or they can tell us if the op likely had a bad run (even by its own physics). But an ensemble can’t correct for the parent operationals biases and core mistakes because it is a derivative of that model. You have to look at other guidance. Furthermore the guidance didn’t fail here. It’s done pretty good. From like 200-360 hours it identified this general setup. And it keyed on a possible event on the mid Atlantic coast. But from that range they cannon accurately predict the discreet details, like a weak wave that lingers and lowers heights some in front of it or a vort cut off under a block meandering around in Canada, that will determine exactly how amplified and exactly where a storm hits. If you’re judging NWP by details on synoptic events at day 7+ then that’s like grading your QB only by his completion rate on 50 yard Hail Mary passes. As we got within 7 days the preponderance of evidence started to show warts that threatened this event. The gfs showing a snowstorm doesn’t mean “guidance says a snowstorm”. The best guidance we have the euro has been saying hold on for days now. The second best the UK was never on board. The ggem was the next most amplified but it was further south and its ensembles were even less enthused. Most of the JV models were south. Taken in totality the evidence suggested the gfs was over amplified. We expected this to happen. We all knew the gfs all alone was likely to cave. I had hoped maybe the guidance across the board was dampening the wave coming out of the west too much but the last 24 hours the lack of why move that way in the euro and UK and the slow degradation in the gfs and ggem had me realizing where this was likely headed. Not for sure yet but don’t look good. Imo guidance has been incredibly good giving us a good idea how this threat was evolving at a good range if you know how to be unbiased and use them.

One last thing...After my last “emotional” post I should admit I’m clouded by location and expectation. If I was DC south this probably would still hold more interest to me and a lot in here are. And if I was just chasing a few inches I certainly wouldn’t give up. But I was kinda big game hunting and just found out there are only some rabbits and squirrels left in my area so I’m going home to drink a beer instead. If an elk just happens to wander by though....!!!!!

Guys I’ve done the whole “reason with yourself” thing but better to just rip the bandaid off. The trends are all the wrong way. And we’re hitting the 100 hour mark where guidance typically doesn’t make huge adjustments to major factors anymore. Today was a crucial day to hold or see improvement and it went the wrong way. It’s not OVER but it’s on life support Imo. let it go. That doesn’t actually have any effect on if this pulls off the rare comeback. Then it’s still gonna feel great. But don’t torture yourself anymore. Don't prolong the suffering. I’m gonna go find something fun to do. Peace.

The ensembles are only as good as the operational they are based on. They can’t help if the core model is wrong. Their usefulness is in telling us of the operational had a fluke run and went off on a tangent due to some discreet error even by its own physics. They offer a scope of variability within the physics of that model. But if the model is wrong about something due to a core bias that flaw will infect the ensembles also. All the ensembles agreeing with the op said was that the op wasn’t a fluke within its own physics parameters. But ensembles don’t ensure the models physical representations are sound. You need to compare to other guidance to determine and guess at that.

Less cold less resistance to WAA less lift less healthy precip shield to the north. We’ve seen that all year with every wave. The path to overcoming that here was when it was an extremely amplified bomb. It’s a balance. A weak wave with a weak WAA flow can create lift by having a deep hard to move cold airmass that resists the WAA creating lift. With less cold you need the flow from the wave to be stronger to compensate. Of course that opens the door to rain lol. See!

It was giving me 8” along the PA line yesterday. Trend.

No this setup is bleeding the wrong way. Has been for the last several days honestly but somehow the gfs continued to amplify the h5 way more then all other guidance anyways. But the trough in front is slowing down more and more, that tpv in Canada is diving south more each run and the combination is compressing the flow a lot more. Frankly had the h5 flow looked the way it does now when I got excited 10 days ago I probably wouldn’t have. Imo the bigger failure is the wave Monday. The progression sped up. That wave is happening during our best window wrt the Rex block and trough retrogression. But frankly the pathetic lack of cold F’d that up. No nice boundary for the wave to focus along, and that’s hey because it’s a surface driven not upper level wave. So it’s washing out and we weren’t even cold enough anyways if it hadn’t to maintain heavy snow. But simply from a pattern progression that was our best shot to get a simple overrunning snow in DC. The timing has changed for the next wave. The trough amplifies too much off the east coast and the ridge stops retrograding behind it. The wave after has a better chance to amplify but by then what pathetically little cold there is has eroded even more since the polar source is cut off. Imo the root of the fail was we had 5 days of epo ridge that opened a direct air feed off the Arctic straight down into southern Canada and the northern US...but that air quickly modified and mixed to become just an average blah airmass. That limited the potential of EVERY discreet threat within the blocking window. Created the double bind. Less potential energy from a weaker boundary. Made us need more suppression to stay cold. But less likely to get amplified waves. It’s not 100% over. Weirder things have happened. But I’m past the point of expecting it.

If this fails the lingering of the early week system which decreases the spacing and prevents ridging from really going up behind it is probably the biggest culprit. It’s the biggest change in the overall pattern from when I looked at it a week ago and really like it. The spacing isn’t as good now. Of course as the system approaches we are barely on the cold side and temps crash as the coastal forms...so whose to say had ridging gone up more this doesn’t cut and jump to the coast too far north like a lot of the gefs members that rained on us the other day. Our “win zone” with every storm is so narrow with the current temperature profile.

Another run that’s close enough not to give up. If it’s going to make a move my guess is we start to see it in the next 24 hours.

....falls apart just as it gets to us. I want off this loop

Storm after the storm....(ducks and runs)

The bombing Atlantic low combined with the blocking suppressed attempts to ridge out in the east. I’m still skeptical we get a big snow threat in the Feb 4-10 window but I could see some mix/icy scenarios and that look towards mid February is potentially very good.

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.