snowman19

2020 is not an analog IMO due to the solar minimum which in very large part helped drive the high latitude blocking

If the end of November pattern on the long range ensembles is correct, that’s a Bering Sea vortex, total lights out ++EPO pattern. That’s exactly what happened back in late November, 2011. It’s even worse than an Alaskan vortex

As strong a signal as you will ever see (rest of this month)

As strong a signal as you will ever see for the rest of this month @Bluewave

The ensembles (GEFS GEPS EPS) are a general 0.2 - 0.4 total QPF Sun/Mon which will seem like a deluge

I’m confident in either a central-based cold-neutral (ONI) or very weak La Niña

@40/70 Benchmark This is going to become even more of a classic central-based Niña

EPS is not enthused at all, with a general 0.2-0.4 total QPF from the Mid-Atlantic through the northeast by Wednesday, which makes me view the GFS with extreme skepticism https://www.pivotalweather.com/model.php?m=epsens&p=qpf_acc-mean-imp&rh=2024110500&fh=204&r=us_ne&dpdt=&mc=&pwplus=1

Hard sell on the SPV weakening. The Euro was awful with doing this last year early on in November/December. And there’s a massive trough in Eurasia exactly where you would want a ridge, which is going to allow the SPV to strengthen as much as it wants

@Gawx Even more confidence in my guess of a hostile NAO this winter. And any word on the October QBO number? Edit: @GaWx Assuming a Dec/Jan peak, I wonder if we meet or eclipse the WQBO record (at 30mb) of +15??

That’s a real good question. It’s clear that by mid-month the SE ridge/WAR is going to pop, then it becomes a question of how strong, which is going to depend on the trough in the west. The +AMO and New Foundland warm pool by itself is supportive of SE ridge/WAR. If the -PNA really dumps into the west then it’s probably more of the same on the east coast (dry) with a stronger downstream ridge @SnoSki14 @Allsnow And the GFS has begun a full scale cave to the drier Euro suite for Sun/Mon. Watch it turn into nothing more than a few passing showers. “When in drought, forecast drought”

Not sure about THE warmest November, but I can absolutely see this being in the top 5 based on what the ensembles are showing right through Thanksgiving

Agree. Showers on Sunday/Monday are not going to undo the damage that has been done since August 20th

Warm Niña falls doesn’t have as strong of a signal as precip. The correlation to winter is stronger with dryness/wetness. Dry falls, in particular very dry falls have a correlation to below normal snowfall

If the ensembles are correct this pattern lasts right through Thanksgiving. This is a very stable, feedback pattern we are in and have been in

Fall dryness/wetness has a much better correlation to the winter pattern than does temperatures @donsutherland1

I think more than the warmth (which has been going on for years now), the big story since August is the record dry pattern. We have clearly gone into a dry feedback loop and once they are in place, they are VERY hard to break

I think this ends up another record dry month and the drought continues unabated

I mentioned it before, but I think the risk is that my forecast of +2 - +4 this winter busts too low given the very rapid acceleration of AGW over the last 10 years

If anything, I think the risk is that my forecast of +2 - + 4 this winter busts too cold given the rapid acceleration of AGW over the last 10 years

My Winter Outlook Here is my winter guess/forecast. Not going into huge detail to bore everyone but here goes. This is for Dec-Mar: Oscillations (average) Dec-Mar: NAO: Positive AO: Positive PNA: Negative/RNA EPO: Positive WPO: Neutral PDO: Strongly negative AMO: Positive, w/continued New Foundland warm pool IOD: Negative, has taken on a decided negative signature the past month ENSO: (ONI) Central-based Weak La Niña/cold-neutral; RONI and MEI will likely be lower QBO: Strongly positive Solar: Very High, continued high number of sunspots, radio flux and geomag activity MJO/Tropical Forcing: Favoring phases 4-6, Eastern Indian Ocean and Maritime Continent forcing. Very strong standing wave/OLR/-VP in that area the entire month of October, pattern feedback loop Temps Dec-Mar average (NYC metro area): +2 - +4 Snowfall Dec-Mar average (NYC metro area): Below normal; *Hardest to predict given that one storm could skew the entire season* Main analog: 2001-2002 Reasoning: Record drought/low soil moisture, pattern persistence since August 20th. Very dry falls correspond to below normal winter snowfall. I believe this continues throughout November. Actually is a way better correlation than fall temps PDO/EPO: Is and has been record negative (-3), Persistent GOA/Bering Sea cold pools favor +EPO PNA: -ENSO, -IOD; favors Indian Ocean and Maritime Continent forcing (MJO 4-6) NAO/AO: High solar; high geomag activity, high sunspots, +QBO, -ENSO, +AMO w/New Foundland warm pool. AO: SPV projected to get very strong and very cold this month, fits with the above (solar, QBO, ENSO relationship). As far as the “SAI”, which I don’t follow for its very glaring failures in the past, but for those who do, Siberian snowcover buildup completely fell apart the last 2 weeks of October and is now perfectly normal. Not saying it’s completely irrelevant, but I don’t buy into it WPO: Marine heatwave east of Japan strongly favoring an Aleutian High/ridge regime, which I believe will be a flat ridge as opposed to a poleward one the majority of the time AMO: After briefly taking on a negative look late this summer, has gone right back to a positive signature. Atlantic SST profile has completely lacked any semblance of a “tripole” at any point since June; favors +NAO and beefed up SE ridge/WAR this winter, as does tropical forcing QBO: Already eclipsed +12 in September, anomalies showing continued strengthening in October. Strongest on record (30mb) is +15, we may approach or even surpass that record when it peaks this winter; thinking the peak comes Dec/Jan Arctic Sea Ice: Record low. I believe this will potentiate the +AO, +NAO. A recent study (2021) found that low arctic sea ice in combination with +QBO (especially in a Niña) results in a strong SPV/+AO Volcanism: Cumulative VEI 5 eruptions of tropical volcano Ruang, which reached the stratosphere back in April. Although this will clearly NOT have the effect of a Pinatubo, it *may* possibly help to magnify the other factors mentioned influencing the AO/NAM Atlantic ACE: Although ACE picked up to normal in October after being much below normal, it is still well below the 200+ number which has shown some correlation to the NAO in the past. So really no big signal either way on that. A non factor this time around Good luck to everyone else with your winter outlooks

There may be a brief, transient period with the tropical forcing? But overall? No

Here is my winter guess/forecast. Not going into huge detail to bore everyone but here goes. This is for Dec-Mar: Oscillations (average) Dec-Mar: NAO: Positive AO: Positive PNA: Negative/RNA EPO: Positive WPO: Neutral PDO: Strongly negative AMO: Positive, w/continued New Foundland warm pool IOD: Negative, has taken on a decided negative signature the past month ENSO: (ONI) Central-based Weak La Niña/cold-neutral; RONI and MEI will likely be lower QBO: Strongly positive Solar: Very High, continued high number of sunspots, radio flux and geomag activity MJO/Tropical Forcing: Favoring phases 4-6, Eastern Indian Ocean and Maritime Continent forcing. Very strong standing wave/OLR/-VP in that area the entire month of October, pattern feedback loop Temps Dec-Mar average (NYC metro area): +2 - +4 Snowfall Dec-Mar average (NYC metro area): Below normal; *Hardest to predict given that one storm could skew the entire season* Main analog: 2001-2002 Reasoning: Record drought/low soil moisture, pattern persistence since August 20th. Very dry falls correspond to below normal winter snowfall. I believe this continues throughout November. Actually is a way better correlation than fall temps PDO/EPO: Is and has been record negative (-3), Persistent GOA/Bering Sea cold pools favor +EPO PNA: -ENSO, -IOD; favors Indian Ocean and Maritime Continent forcing (MJO 4-6) NAO/AO: High solar; high geomag activity, high sunspots, +QBO, -ENSO, +AMO w/New Foundland warm pool. AO: SPV projected to get very strong and very cold this month, fits with the above (solar, QBO, ENSO relationship). As far as the “SAI”, which I don’t follow for its very glaring failures in the past, but for those who do, Siberian snowcover buildup completely fell apart the last 2 weeks of October and is now perfectly normal. Not saying it’s completely irrelevant, but I don’t buy into it WPO: Marine heatwave east of Japan strongly favoring an Aleutian High/ridge regime, which I believe will be a flat ridge as opposed to a poleward one the majority of the time AMO: After briefly taking on a negative look late this summer, has gone right back to a positive signature. Atlantic SST profile has completely lacked any semblance of a “tripole” at any point since June; favors +NAO and beefed up SE ridge/WAR this winter, as does tropical forcing QBO: Already eclipsed +12 in September, anomalies showing continued strengthening in October. Strongest on record (30mb) is +15, we may approach or even surpass that record when it peaks this winter; thinking the peak comes Dec/Jan Arctic Sea Ice: Record low. I believe this will potentiate the +AO, +NAO. A recent study (2021) found that low arctic sea ice in combination with +QBO (especially in a Niña) results in a strong SPV/+AO Volcanism: Cumulative VEI 5 eruptions of tropical volcano Ruang, which reached the stratosphere back in April. Although this will clearly NOT have the effect of a Pinatubo, it *may* possibly help to magnify the other factors mentioned influencing the AO/NAM Atlantic ACE: Although ACE picked up to normal in October after being much below normal, it is still well below the 200+ number which has shown some correlation to the NAO in the past. So really no big signal either way on that. A non factor this time around Good luck to everyone else with your winter outlooks