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Pattern Marvelous March

Rain Cold said:
GEFS support doesn't really mean anything over one or two or three cycles at 168. We've seen this over and over and over. All kinds of groovy looking ensemble members that morph to 0 as we move in. What we need is broad model good agreement on a credible synoptic scenario that makes for an anomalously far south cold press a legitimate possibility. What we have is this:

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What is there to press the PV that far south just prior to and during the storm, thus allowing cold air to be tapped and the storm to stay south? I don't know, but I do know that we've seen this same look show up a lot, only to verify farther north. I wish we had a big block up north of it. That would help. I do like the high pressure though. Maybe we can rely on that? But we've seen those verify weaker also. But maybe we get lucky this time.
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Yeah there isn't anything keeping the PV from going north. The only reason I see it being as far south as it is could be the high in the plains tapping into the cold pulling it slightly and pushing the storm system south. Also note the GFS is the only model creating a sharp ridge in the Rockies which triggers the dive as well. It's too fishy of a setup to believe as we have stated.
 
We are having the last strat warming event which is having something to do with this scenario. I know most are doubting it because its late in season, but if yall recall end of March through april was way below normal. Sometimes patterns repeat
 
GEFS cold bias and clown maps almost always being way overdone notwithstanding, the 12Z GEFS is colder than the 6Z, which was colder than the 0Z, etc...all the way back to 5 runs ago or yesterday's 6Z for 3/26-8. So, the model cooling trend may not be over yet. To show how much colder today's 12Z GEFs is vs yesterday's 6Z GEFS in the E US for 3/26-8, yesterday's 6Z averaged 12 HDD or 53 F vs today's 12Z GEFS averaging 26 HDD or 39 F!! Normal is 52.5 F. So, the GEFS went from right at normal yest at 6Z to 13.5 F colder than normal on today's GEFS. I fully realize that the GEFS strong E US cold bias must be taken into account to project what may actually happen, but even so the major colder trend is very notable and the E cold bias is quite a bit smaller than 13.5 F at days 7-9. It is more like 5-7 F. So even after backing that out, the 12Z GEFS is much colder than normal for 3/26-8. For the SE itself, it would still be some 20 or so F colder than normal for 3/26-8 even after backing out the cold bias, which would be 7 or so colder than normal for mid Jan!
 
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Very strange setup and storm trajectory here. CR touched on this. That alone is enough to give me a hope. This one is far from settled but if winter 2019 has taught us anything it’s going to verify well north

At least the PV is situated east this time (for now). That can’t hurt
 
Golf7575 said:
We are having the last strat warming event which is having something to do with this scenario. I know most are doubting it because its late in season, but if yall recall end of March through april was way below normal. Sometimes patterns repeat
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I wouldn't be shocked to see a cool period prevail over the next 3-5 weeks or so. Cold enough for snow? Not nearly as enthusiastic about it. Is the strat warming underway right now? I admit, I haven't been following it very much. Don't such events usually have a fairly substantial lag, if there are to be effects at all?
 
As part of this discussion, here are the latest 5h 5h verification scores. Recently all models have seen quite a dip and appear to be struggling a bit more for some reason.
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Also the 12z GEFS snow maps/mean don't fully capture the wintry scenario the members are depicting. Quite a few show a mix/ice before changing to snow or rain which won't show up on the snow maps. Here's a comparison to the 12z vs 6z run. I would say the 12z run is definitely a step in the wintry direction with many colder/south solutions vs 6z. Interesting to note at the very least.
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snowlover91 said:
Also the 12z GEFS snow maps/mean don't fully capture the wintry scenario the members are depicting. Quite a few show a mix/ice before changing to snow or rain which won't show up on the snow maps. Here's a comparison to the 12z vs 6z run. I would say the 12z run is definitely a step in the wintry direction with many colder/south solutions vs 6z. Interesting to note at the very least.
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Can we rule out e19 since it’s a raging late March ice storm deep into MS SC and GA?
 
Anyone have precip maps ... 850s look meh on the euro but a very similar track and scenario Gfs shows ... I’ll take that look with some hopefully hyped up ensemble members
 
We all know that clown maps are almost always overdone. But for the fun of it, I analyzed the chance for the 1" that the 12Z GFS shows for Augusta on 3/26 to verify per history:

Back to 1946, Augusta has received measurable March snow only twice: 0.7" on 3/11/1960 and 1.1" on 3/2/1980. So, 1" as late as 3/26/2019 would be nothing like anything they've gotten in 70+ years.

Now, what about nonmeasurable? These are the dates: 1, 1, 2, 2, 2, 3, 5, 6, 9, 13, 24, and 25. Since they've gotten none in April, even just a T on 3/26/19 would be the latest snow on record. The closest were the traces on 3/25/1971 and 3/24/1983.

Conclusion: don't bet on measurable at Augusta on or near 3/26/19. A more reasonable hope would be for a trace though that won't be easy at all. The best bet by far is for none.
 
GaWx said:
Unfortunately, the 12Z Euro has no snow for the SE unlike the 0Z Euro and the last 4 GFS runs.
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850s start off cold but then fade and our 5h low never really gets going. The GFS on the other hand phases some energy in which helps to keep some colder air aloft over the SE for the snow. Overall the 5h presentation of the Euro and GFS are similar but differ in regards to timing and interaction of the 5h energy. That's something that probably won't be properly resolved for several more days.
 
This is what you want if you want snow here in NC. The 5h low begins to slow and the base of the trough turns neutral as the various pieces of energy interacts. If this interaction occurs too soon the system would slow up and cut to our north like the CMC/ICON show and likely bring a severe threat. Too late and the system juices up offshore and we see a cold rain. As usual a very delicate setup and we would need perfect timing to get this to happen.

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