Stormchaserchuck1

Everything is a bit west at 10-11hr 20z Hrr vs 19z

3-4 hours of heavy snow on 20z RAP, I-95 and NW

closed 500mb https://ibb.co/Fg4gcGV

19z Hrr appears to be shifting a little south vs 18z.

19z RAP gives DC 4".

It's transferring, but yeah a little SW.

Low pressure is on the VA/NC border at 16hr vs being off the coast of OC 22hrs 12z.

Precip not in NYC at 14hrs vs being in central Mass at 20hrs 12z. Storm is a little SW.

Pretty big differences on the 18z NAM for being 10hrs out.. sea-level low is further SW.

wow.. still stronger near NYC

18z Hrr is trending a little south 17hr vs 17z

whoa the 17z RAP still snowing

3z RAP isn't impressive down here, It's similar to the 0z GFS. SNE gets nailed on it though.

Fwiw, 2z RAP is SE of the 0z GFS with SLP at 21hr. https://ibb.co/s9XvCSg

New superstition: unpin threads that are going to snow. That one thread that we had pinned it was 80 degrees the day before.

BAM. 2" in NE, MD on the 0z Hrrr

0z vs 18z Hrrr so far https://ibb.co/0ZvwBnb

I forecasted a +PNA, but a lot of the CPC's calculations include Alaska and the Gulf of Alaska.. I'm mostly referring to Aleutian islands central-north N. Pacific trough, in reference to +PNA. In that regard, this Winter has not matched usual ENSO correlations, and really the whole event has been like that, since the Nino developed in April.

21z RAP

I edited to say that storms are digging into the West coast with more frequency though.. And general High pressure over the SW hasn't been as constant a force the last few years... so maybe we are starting to change the longer term processes (related to the Hadley-mid latitude Cell)?

You're right.. I underrated the -PDO this year. 5/5 non+PNA Mod/Strong Nino Winter's is a pretty compelling stat! If -PNA is wetter and +PNA is drier, imagine how much the difference is if you don't account for ENSO! +PNA's have been associated with El Nino's 80% of the time historically, and visa-versa. With wetter than average conditions in El Nino, what a difference the PNA makes in precip-correlation in non-ENSO times. That's why -PNA's in El Nino's have been historically good with -NAO/AO conditions. The Hadley Cell is just expanded right now.. With storms digging into the West Coast the last two Winters though, I don't know that, that isn't in the process of changing..

18z Hrr has a brief period of snow at the end.

Major trough in the NW on LR 12z GEFS.. that's been the Spring pattern lately. https://ibb.co/ZBq1Dqm

I know if we get a Stratosphere warming soon, like a lot of models are saying, we could get a bigger -NAO down the line. That was really my basis for thinking this could be a better Winter. This will be the 3rd Stratosphere warming.. another strong ENSO/strong QBO hit on 10mb conditions.

I like the EPO negative, and +PNA we haven't really seen this Winter. I was just pointing out that LR models have been really bad, they keep showing an El Nino pattern, but since the El Nino developed in April, we never had a +pna. In Oct-Nov, I was saying the mean pattern in the SW N. Pacific was a ridge for a Strong Nino! It's no surprise the Euro weeklies busted and we only have some weak +pna in the medium range here. I'm worried that next Winter the pendulum may swing completely toward what you are calling -PDO. I get what you are saying about patterns that used to work.. and I agree, the PNA has a precipitation correlation here that is actually greater than the temperature correlation in the Wintertime! That means, the net air temps+precip makes -PNA more favorable for snow than +PNA. The deceiving thing is coastal lows form much stronger in +PNA, there is a +0.3 correlation vs -0.3 for -PNA.. so if you look at SLP you would say +PNA Is the obvious better pattern for snow. I think it's somewhat +AMO related. We've been getting this ridge where the Hadley Cell meets the mid-latitude Cell.. it started on the West coast, and especially the SW where it stopped raining after 1995. The Pacific Jet used to go into SF a lot, now it doesn't even rain there anymore.. the jet goes all the way up into Alaska.. Over the last few years, that pattern in the mid-latitudes has made it to the east coast. The AMO changed in 1995, so I would say maybe wait for that to wane.. also, according to the CPC we aren't getting -NAO's nearly as much these days, and the WPO has been positive a lot.