Carvers Gap

The 18z GEFS and AI GEFS are AIFS Euro are COLD in the window that we need them to be. Keep the STJ cranked, and let's roll.

Basically, the 18z GFS traps a piece of the TPV under HL blocking. It just sits and spins while locked over central Canada. This is what ensembles might not be able to see. It kind of looks like LR ensembles w/ a SER. But...that SER is minor as it is getting lifted into place by the strong BN heights over Canada. The HUGE plus on this run....storm track is right over our forum area w/ repetitive winter events.

After 200, the juiced STJ is firing right into an inbound Arctic air mass.

We got JB talking about a d15 warmup. Meanwhile, this GFS run is going to have it snowing in Cuba.

An outlier the 18z GFS may be...it is about to send it.

Haha. That is just an insane HL blocking run by the 18z GFS. It is either the beginning of a trend(and I have seen more NAO recently on modeling in this time frame) or this is a toss. It is a beautiful pattern, but for sure an outlier.

The 18z GFS continues the trend of bringing light snow to the region around Jan 15. Miraculously, a huge NAO is in place.

Great discussion in here this afternoon. I enjoyed reading all of that - even if it isn't all snow!

The interesting thing about La Nina...there are a few analogs which aren't dry during winter. I think @John1122 has posted those thoughts prior. In fact, they can produce flooding rains at times. I don't think we are out of La Nina quite yet. That said...there was worry about Canada losing its cold. The 12z Euro(yes, it is at the end of its run, but has support from its ensemble and across some other models) had this at the end of its run. Let's see if the 12z CFSv2 can get on a run. If flipped cold for Jan 21-31. I probably is a blip, but the image below kind of fits where I think we are going. The coldest air is going to push into the Canadian Prairie and refuse to budge. I am sure the West will get its fair share...but one good cutter, and any warm-up would go poof! This also fits exactly what LC's analogs have shown for late winter. Can you imagine what the Lower 48 would look like w/ a strong amplification in either of the blocking areas would produce? The SER will fight, but w/ that air mass as a plausible option...we may need a little SER.

1). The 12z Euro appears to have some chances as well w/ multiple vortices and energy climbing the EC. That pattern is loaded w/ chances every few days. 2) If you watch the end of that run, the western ridge rotates rapidly west through the Aleutians. It moves so rapidly, it might well allow the EPO to rebuild. If you look at the end of the GFS run, it sticks a trough out West. But the ridge in the Aleutians moves so quickly that you can almost see the ridge sliding underneath the western trough, ie the eastern trough is already retrograding. 3) I don't lose a ton of sleep at this time of year. What I "think" is going to happen is part of the TPV is going to crash through central Canada and almost force a trough to stick in the center of the continent vs out West. The SER will fight it, but cold will push against it as it pinwheels around that trough IMHO. I think the 12z AI GFS is the extreme eastward version of that look. I think the Euro is about right...I might nudge it a bit west - speaking of 300hrs +. 4) Again, I remain optimistic that the Jan11-21st time frame is a good one for wintry weather. Then, we get a TBD break(could be quick). Then we repeat the same cycle. Again....One variation(instead of a western trough) I think has some merit is the 500 TPV rotates int0 central Canada on its throne, and makes everything work around it. Very blocky looking pattern.

The 12z GEM has a storm along the coast during the 14-15th and a northern vortex crashing in. Close miss but still some snow. Good overall pattern though. As for Bam, I generally have steered clear of that site most winters....flip-flop city but some really good content at times. Right now, the MJO seems decoupled from the NA weather pattern to some extent (certainly some influence). I think the window from the 11th-21st(maybe a little longer) is a good window. Then, it looks like another ridge will retrograde through the East. The positive from the GFS is that it RAPIDLY moves the Alaskan ridge through the Aleutians into Asia. The faster that goes, the faster that we see the ridge develop in the West again. February looks like it will have another deep trough develop between Feb1-10. Remember, I am big on finding windows for winter precip, and then watching details as that window draws closer. I do think there is a chance the ridge locks out West, but maybe a 40% chance on that.

Man, the 12z GFS is just barely missing on some decent chances. By 258 and just barely in fantasy land, the 12z GFS looks very similar to its AI counterpart. Jan 17 is kind of a timeframe I have circled when the base of the trough flattens out, and allows for storms to slide across.

The 12z ICON buckled the jet further west than the 12z GFS. I wouldn't be surprised to actually see a cutter in that time frame...that is how "off" that run was Jan14-15 on the 12z GFS.

I will say the 12z GFS still rotates a lot of energy at 500 through the northern stream. It barely missed a phases right there w/ the southern stream. The southern stream energy was just slightly ahead. I wonder if that is going to end up being a storm?

Looks like we are going to see this cycle back through one more time w/ the retrograding ridge...might be two more times. I think February, w/ at least one pause, could be an interesting month. Did you see the end of the 12z AI GFS...that is a HUGE trough. I suspect we see a ridge pop over the East at that time, but the AI GFS isn't on board with w that idea quite yet. That trough is how record lows are broken. Huge grains of salt at this range. 12z GFS looks pretty dry so far. The trough is slightly too far to the East.