Bob Chill

Think of it like this. Even when northern Canada or the Arctic Circle temps are "above normal" that still means below zero. What all that ridging in the high latitudes does is it displaces cold continental airmasses southward into the mid latitudes. Above and below normal temps are relative to latitude. A +20 arctic circle airmass is -10 if it gets pushed over us. The panel you are looking at isn't big cold but it's below normal and that's all we need during jan/feb.

We'll have to wait and see if it's right but week 3 on CFS weeklies looks exactly like d15 on the ens. Shows a +preip anomaly along the east coast as well.

Yep, close to a lock that we get a period of deep cold sometime after next weekend. 18z gefs has a really nice look d10-13 for a SE storm. A lot has to happen first so focusing on anything specific is like a dog chasing its tail. All systems go beyond d15. The end of the EPS and GEFS both look the same and it looks pretty damn good. One thing that wasn't around much in 2014 and 15 was the southern stream. Ensembles imply active southern stream down the line. Hurry up and wait but at least we seem to be waiting for a longer duration favorable period. Could continue well into Feb. All weekly/monthly/seasonal guidance looks almost identical for Feb. Not perfect but magnitudes better than anything we've seen this year. Won't truly believe it until I'm shoveling though...

I like sticking to the 3 day rule meaning frozen precip starts within 72 hours or less. Some setups can get away with 4 day rule and this may be one of them if all 0z and 12z ops show frozen without degradation. We're walking a line with temps. Delay precip or miss the warm front WAA piece and it's a 100% rain storm

@psuhoffman if we aren't going to have a -ao/nao, the current d15 mean h5 across all ens is the next best thing imo. Feb 2015 was mostly northern stream. Most of 13/14 was northern stream except the Feb storm. Current look is like 2014/15 + southern stream. I can't really recall any winter in the past 15 years that had a similar hemispheric lw pattern

Lol. Only if you don't want any snow this weekend.

Keep this in mind going forward... After next weekend we look to enter a period of split flow. Ops will never ever ever be remotely close to accurate 10 days away with split flow regimes because the northern stream holds the keys and ops can barely get the NS right within 5 days. Stick to ens guidance only and even then it's just general ideas.

Intriguing panel... Haven't seen a d10 fantasy setup like this since 2016....

Def not the same algo as last year. If you flip between ptype and snow maps it clearly shows that zr isn't counting. Sleet is muddy but doesn't look like 10-1 to me. Models are converging on a step down pattern taking place over a week. I'm not expecting real cold or deep winter appeal until 11-13 days down the line when the what appears to be a classic -EPO arctic dump. First couple fronts starting next weekend are prob nothing more than return to normal winter here. Beyond that looks like real winter with temps. Snow tbd.

Yea, no big deal about next weekend. It's never looked like a good storm. Just one of the ways we stat pad on the regular around here. Even if it totally blows up it's nothing more than a beginning of a new regime. Our chances should progressively increase as we move forward.

I think you mean the 1st? Euro monthlies are run once per month unless I'm out to lunch. Feb looks just like the cfs monthly/weekly and is basically a Feb 2015 redux. Right or wrong, it's remarkable have well everything agrees for Feb. There are a number of reasons to be encouraged that winter starts next weekend and holds on for a while

Here's how I look at it... this winter has pretty much been epic disaster so far. We've all paid our dues already. There's a half decent chance that the pattern on deck is generally favorable for multiple weeks in a row. Even if the 18z gfs played out it's still a good a good look at the end. As long as the later periods on the ens keep looking ok I'm not going to stress about anything. OTOH- if the pattern flips back to abject failure before Jan is done this place will implode and we can call it a winter and meet back here next fall. The good thing is the CFS, Euro Weeklies and CanSips all look basically identical in the Pac for all of Feb into March. I know seasonal and weekly guidance suck sometimes but seeing unanimous agreement is encouraging.

The shortwave that hasn't formed yet and needs to travel 8,700 miles hasn't been sampled.

@psuhoffman All weekly and seasonal guidance says that EPO ridge is here to stay through Feb. If that's the case it would take some pretty bad luck to not have multiple events. Fun period coming up. We should be focusing mostly on 7 days or less by late next week. D10+ is tiring every.single.year

Yea. Wut?

18z gfs is basically an epic disaster

If you loop H5 and MSLP panels with the hemispheric view... it looks like the EPS is setting up an Archambault event right at the end. -NAO flips + and mslp anomaly shows a potential coastal climbing the coast in the SE. Total fun fantasy talk but I'm not lying.... Eta: picture worth a thousand words... haven't had a miller A in 4 years... Eta #2: what PSU said already. Lol. We're telegraphing thoughts is seems.

EPS is decent next weekend. Better than 50% odds of 2"+ of snow before ice/sleet/rain. Later in the run looks pretty much like the gefs.... level up weenies

If you keep it simple and just go off history and our climo, a west track mixed event is the most likely option imho. Luckily thess types of events are usually mostly locked in by d4-5 since it's not a complicated upper level dance or phase. Just root for as fast and juicy as possible Eta: by locked in I mean general track/progression. Devil is always in the details. Hope we get to the point where some snow is guaranteed and we're only discussing how much

Anyone who frets an op run needs to click on hr 192 panel of the gfs on TT and click previous run 10 times and see what amazing consistency there is run over run.

If it wasn't for stupid dumb P12 it would be unanimous 2"+ on all members at DCA. I want to kick P12 right in the pill box. For those with digital snow fetishes... might want to view this post in private

Man, you guys gotta be lovin the 12z gefs. Really upped the odds of a SE frozen event. Considering how far out in time the window is it's remarkable how many member solutions drop snow/ice/sleet in the SE. Hurry up and wait for now but at least there's reason for some optimism

Heather Archambault. Science behind big east coast storms that happen between phase changes of the NAO. Ours usually happen when the NAO flips neg to pos. One of the reasons it gets warm after big coastals because the NAO relaxes and cold retreats.

I do like seeing the gefs and eps picking up on numerous solutions that dump frozen in NC. One of the clues I look for when assessing bigger storm risk. 12z gefs continues its weenie streak. Another very wintry and good looking run.

Yea, we're 2 synoptic events away from that window. No chance models have anything nailed down. Gut says mixed event likely as it's a bread and butter type of setup and we have a lot of experience with these kinds of deals. If it breaks wrong and is all rain then disappointment won't last long me thinks