brooklynwx99

there have been some posts on next week's potentially exciting pattern, so I thought I'd share some more coherent thoughts... the main driver for this change in the pattern from -PNA/+EPO to +PNA/-EPO will be an anomalously strong +EAMT (east Asian mountain torque) that will develop over the next couple of days. HP is around 3-4 sigma above normal here the way EAMT works is that since the pressure gradient force is pointed to the west (wind blows from HP to LP), the Pacific jet must extend in order to conserve the total momentum. we see this Pacific jet extension here: the Pacific jet extension then forces a strong Aleutian / GoA LP (yay El Nino) that leads to an anomalous -EPO that is also timed up with a +PNA! no more -EPO/-PNA crap from last year, it seems. these patterns are very efficient at driving Arctic air into the CONUS, especially the Plains eastward. given split flow and the displacement of the TPV into SE Canada, there is certainly an increased risk at seeing wintry weather, even south of the M-D line. either way, there is a reason for this pattern to develop... I don't think it's model fantasy BS

here's a glaring example of a -EAMT that leads to a jet retraction. pretty much the opposite of what we have going on in the near future

i usually don't use the raw data, I just look at pressure anomalies over Asia. there is a strong HP over Mongolia and China with strong LP to the NW and in the Himalayas... the PGF from these systems points to the west, so the Pacific jet extends and increases strength in order to conserve momentum the opposite is true with strong LP into eastern Asia

+EAMT leads to jet extension leads to this... it all tracks IMO

and then a nice +PNA/-EPO pattern showing up around Thanksgiving. could definitely see some potential for snowfall with this setup

this is how you’d get an early season event. really stout +PNA/-EPO on the EPS

really nice -EPO/+PNA showing up on the EPS

i’m pretty sure this is going to couple well in the N Pac. 500mb (which is generally driven by ENSO) drives SSTs, not the other way around

out to lunch, apparently

this is how you get it to snow early on. nice cross polar flow there probably a transient pattern but it would be nice to get on the board early

i mean, this is what i've been thinking for a month or so now. seasonals generally look like this and so did your blend IIRC

guidance is largely following analog blends, which gives me more confidence in it the JMA is aggressive, but with how far west the VP has been, back the Aleutian low up and that's what you get

if the Nina lag plays a major role this winter, i am never long range forecasting ever again

i wouldn’t take this exact solution to heart. just get ready to see a good amount of cutters over the next month or so. that’s the Nino December M.O.

i doubt it. it’s probably getting back to near normal once we head into December, and then there is the chance for weakening. this is a temporary spike

i agree with that. it’s just that the main issue in stronger El Niños (if they do end up sucking) is that there are a lot of coastal storms with no cold air. that was 1997-98’s issue

for December yes, but i wouldn’t expect cutter patterns as we head later into winter

i think that’s kinda silly. i’m not sure how it would play out like that in actuality

i will say this… if December turns out good, it’s probably going to be a rocking winter 2002 and 2009 would immediately fit the bill if December produces

this was the hypothesis that a big block with Nino forcing would work a lot better. nice ridge over BC

holy shit lmao

the catch is that that is a Nino pattern features a trough in the west

like why does everything have to be so declarative? it makes no sense. it’s okay to not know what’s going to happen

inevitable? three consecutive trimonthly periods that average 2.0+? i wouldn’t consider that inevitable at all

C3S is still insistent on a more CP-type pattern as we head into the back half of winter. looks better than the October run