Stormchaserchuck1

Wow big ice storm for MD on the GFS!

SSWE occurring in 15 days would actually have the greatest effects on early March, -NAO. I get what you're saying though..

It was a big model shift at 500mb in the Pacific. In the Day 10+, I rarely see ensemble means going over +300dm (which is what it was showing in the Aleutian island/PNA region). That coupled, with what I believe is still a strong -PDO in the thermocline and negative ENSO subsurface, showing at least Weak Nina conditions, plus a record streak of 7-years of February -PNA, and I thought that was a good forecast going forward.. It seems the pattern we saw in Dec/Jan ends up having some staying power. Now models backed way off the -PNA ridge in the N. Pacific, but I wouldn't totally discount a trend back toward this in the coming days. It's actually very sensitive because the potential +precip pattern is currently projected to be very close to rain or snow in the Mid-Atlantic... if we see a resurgence of the -PNA the storms will go north and we'll get rain, if the EPS continues to lead they way and we have neutral PNA H5 anomalies and more -EPO, then we might be able to get some snow out of it. I'm still more excited about the wintery threat at our doorstep than the LR models right now.

-EPO/+NAO is the pattern.. Pacific has stronger input with our warm/cold temps. -EPO in mid-Winter can do it!

I'm not expecting any more than a dusting on the front edge.. in PA you might do 1". 850mb temps warm up real quickly though.. accumulating snow is mostly dependent on precip making it in real early Wednesday

0z NAM has 1-2" Wednesday for Cecil County and southern PA.. it also looks like a legit ice threat for northern MD

The PNA is such a huge area.. that trending from +300dm to +50dm or so, means that we can probably get snow mid Winter. -NAO I am still a little skeptical about, they might be overdoing the "no longer strong +AO" pattern of Stratosphere cooling turning into PV split.. it's still a neutral anomaly at 10mb, and historically warmings are 3:1 correlated to +time-to-the surface vs 0-time. Plus last Winter they showed so much of this pattern at days 10-15+, I think the fundamentals of -PDO and Weak Nina, although obviously weak this Winter so far, might still creep up there at the end. They may say the surface of PDO is neutral, but it's still strong -PDO in the subsurface/thermocline. Hopefully the 500mb pattern projected by models holds going forward, I actually hate -PNA in the Winter.

18z GEFS went all out Polar Blocking at the end of the run.. caved to the EPS. Scandinavia and NW Russia are going to have a 5700dm block.. +600dm! at Days 4-5, so that's actually a really good loading pattern for -NAO. It rolls forward to about a +120dm -NAO in ~+10 days. I wonder if the models have bias at all with this historical tendency.

I have sleet

Someone should make a thread for Feb 5/6. We will probably get WWA's

-PDO Strong El Nino is 65/66, 72/73, 23/24.. 65/66 was -NAO and a little weaker ENSO. But if you used the 72/73 analog last Winter you would have done good... subsurface water temps might be the better gauge. This Winter has shown that the PDO can be mutable to other factors/atmospheric drivers.

Previous temperatures don't matter as much as you would think.. water is heavy so the surfaces quickly change to the water temp. Plus this 5th/6 storm is happening at night.

Going to be a close call

GEFS still has this.. Maybe it's a bias because of how the last 7 years have gone in February? It's had the pattern at Day 13-15 for the last 7 days, and it doesn't seem to stick as the times get closer You can see the differences between the two models in the Pacific

EPS is bringing back the Dec/Jan pattern

A little bit because it had the full -PNA pattern (WC trough, EC ridge) for several consecutive runs and +300dm in the mean.. If we never see a -PNA from this, it's major kudos to the EPS because yeah I didn't think it would occur like that

Yeah.. that looks nice. Hopefully they aren't underdoing the SE ridge.

Let's see if ensembles trend toward a better 500mb- that seems to be the trend. Would be a big score for the EPS if -EPO holds over -PNA.

Nobody cares about the ice storm Wednesday? That's more interesting than LR GFS.

Models seem to be changing on the 500mb pattern. Still early, the GFS has been really different 4 runs ago to this run, so would like to see some consistency..

You kind of make stuff up sometimes. You did the same thing earlier in the year saying that in the ENSO thread there were people hoping for X for Y Winter. Never happened. I can also assume you are pointing the new users/guests to my post, since there is no one that has really posted analysis?

Oh my! There's a major storm on the GFS for the 5th. snow then a lot of ice. 24 hours of frozen!

A lot of the long range factors were unfavorable for cold/snowy though.. it's important to keep that in mind when looking ahead to the long range, the QBO is still record positive, which with a Weak Nina favors cold 10mb conditions, or at least not a Major Stratosphere warming. People can freak out about the 10mb PV being split, but it's very close to a near neutral anomaly, so the best that is, imo, is a "not super +AO". -PDO, west-based Nina, etc... If the MJO can stay strong going into Phase 8 late February, maybe that is something to watch, but I've seen this Scandinavian ridging trying to break that NAO in the long range before, and it seems to be something just runs with more -PNA. We'll see I guess.

I've just seen the look models before.. it's a difficult one to change. If you really want to get down to it, we have a Weak Nina right now.. even during the late Nov - mid Jan cold period there was +OLR and +SOI, and other things Weak Nina-like, especially during the end. In late December the subsurface ENSO went from Neutral to pretty moderately Negative. I've researched this, and run numbers, and a negative anomaly in the central-ENSO-subsurface region at 150-200m correlates to -PNA conditions. Because it didn't happening immediately when the cold pool flared up and was a bit lagged, I feel it may stick around longer now. I've seen this time of year -PNA... after Jan 27th, the coldest day of the year, it's like a switch flips, and we go -PNA for whatever reason. Because it's aligned with the warming/cooling cycles of the Hemisphere, it seems to be somewhat of a permanent pattern. I think you agree that the snow prospects are slim for the next 15 days. If the pattern goes more -EPO like the EPS has, that favors maybe some ice, but models are pretty consistent on having an East Coast/mid atlantic ridge at least through day 15. Beyond there, you seem to be bullish on it getting cold again, but I've seen these LR ridges try to change a -PNA in the long range, by overtaking the NAO or whatever, and they don't work out as well in verification as you would think.. the RNA pattern is a stubborn one and can be difficult to change. I do think we could see some breaks, but probably not the late Nov - mid January cold that we just experienced. It's hard to pattern change. That doesn't mean that it can't happen, it's just a little lower confidence right now on the Day 16+.

This ridge from Californina to Russia is a good example of what a cold 10mb (Stratosphere) looks like near the surface, as the effect of a stronger Polar Vortex at the Pole speeds up, and makes it down like the funnel of a tornado at 0-time. On its edges, in the midlatitudes a ridge is flexed. Below you see the down atmospheric effects of a cold/fast 10mb level, which is centered over western Greenland and the Davis Strait currently. Cold Stratosphere correlates to 500mb at 0-time. Warm Stratosphere corrleates to 500 at +15-45 days.