GaWx

I looked at the NYC snowfall for the 17 -ENSO winters for which Dec was cold and had snowfall of 6”+ (from @donsutherland1updated list): Year (Dec)..Total Season..Jan+ 1872….60.2….29.9 1874….56.4….46.3 1886….31.9….21.6 1893….39.2….30.9 1903….32.4….26.0 1909….27.2….17.4 1915….50.7….42.6 1916….50.7….36.2 1917….34.5….20.1 1922….60.4….51.4 1926….22.3….10.6 1933….52.0….36.6 1942….29.5….21.0 1944….27.1….20.4 1995….75.6….61.2 2000….35.0….21.6 2010….61.9….41.8 ———————— Analysis: -AVG of these Jan+: 31.5” vs 22.1” full 156 year record mean or 143% of mean for Jan+ (median was 29.9”) -41% (7 of 17) had 35”+ for Jan+ vs only 12% of the other 139 (17 of 139) -These 17, which are only 11% of the total 156 on record, had: 1. Highest Jan of the 156 on record (2011’s 36.0”) and 3 of top 5 Jans (2011, 1996, 1923) 2. 3rd highest Feb of the 156 (1934’s 27.9”) 3. 2nd highest Mar of the 156 (2016’s 25.5”) 4. Highest Apr of the 156 (1875’s 13.5”) and tie for 5th (1917’s 6.5”) ————————— My NYC total 2025-6 snow prediction based on these stats: 40” (most likely range 30-50”) This compares to 156 year and 35 year means of 28”.

I looked at the NYC snowfall for the 17 -ENSO winters for which Dec was cold and had snowfall of 6”+ (from @donsutherland1updated list): Year (Dec)..Total Season..Jan+ 1872….60.2….29.9 1874….56.4….46.3 1886….31.9….21.6 1893….39.2….30.9 1903….32.4….26.0 1909….27.2….17.4 1915….50.7….42.6 1916….50.7….36.2 1917….34.5….20.1 1922….60.4….51.4 1926….22.3….10.6 1933….52.0….36.6 1942….29.5….21.0 1944….27.1….20.4 1995….75.6….61.2 2000….35.0….21.6 2010….61.9….41.8 ———————— Analysis: -AVG of these Jan+: 31.5” vs 22.1” full 156 year record mean or 143% of mean for Jan+ (median was 29.9”) -41% (7 of 17) had 35”+ for Jan+ vs only 12% of the other 139 (17 of 139) -These 17, which are only 11% of the total 156 on record, had: 1. Highest Jan of the 156 on record (2011’s 36.0”) and 3 of top 5 Jans (2011, 1996, 1923) 2. 3rd highest Feb of the 156 (1934’s 27.9”) 3. 2nd highest Mar of the 156 (2016’s 25.5”) 4. Highest Apr of the 156 (1875’s 13.5”) and tie for 5th (1917’s 6.5”) ————————— My NYC total 2025-6 snow prediction based on these stats: 40” (most likely range 30-50”) This compares to 156 year and 35 year means of 28”.

Our area had a sweaty 80 high today.

When you consider that both the EPS and GEFS have had a notable -PNA bias/notable warm bias from your area eastward and that all -ENSO -PNA Decs have transitioned to +PNA Jans, these consistently much better pattern maps for mid-Jan are quite encouraging. Just 5 days ago, the EW had this ugly -PNA for 1/12-18:

I’ve been quite curious about what phases the MJO would be in during the heart of the widespread historic US warmth of late Dec, Dec 23-27. We needed to wait due to several days of reporting lag. Would any of it be in the typically chilly in the E 1/2 of the US phase 8? Well, now we have the answer for the first 3 days, Dec 23-25: not surprisingly, none of those first 3 days were in phase 8. It turns out that Dec 23-4 were in very weak phase 7 while Dec 25 was in very weak phase 6, which I consider intuitive: 2025 12 23 -0.28945175 0.37228486 7 0.47157007 Gottschalk10_method:_OLR_&_ACCESS_wind 2025 12 24 -0.12800699 0.45807526 7 0.47562456 Gottschalk10_method:_OLR_&_ACCESS_wind 2025 12 25 0.16766728 0.36077648 6 0.39783412 Gottschalk10_method:_OLR_&_ACCESS_wind Based on a combo of the above diagram and a related adjustment to the model prog consensus, I’m predicting that Dec 26th will be in very weak 4 and Dec 27th will be in either weak 3 or weak 2. Will we get back into phase 8 before the end of Dec? The GEFS, JMA, and CFS with my adjustments suggest likely not whereas the adjusted Euro suggests there’s a chance for at least one day of weak 8 then. Will we get back into phase 8 in early Jan? As of now there’s a moderate chance of mainly a weak 8, but that’s all I can say right now due to model disagreement and it being too far out for a confident prediction.

For -ENSO (17 seasons): 1872 10.6 1874 14.5 1886 6.6 1893 9.4 1903 15.6 1909 11.1 1915 0.7 1916 5.8 1917 13.2 1922 24.5 1926 5.7 1933 0.1 1942 9.5 1944 12.3 1995 26.1 2000 8.3 2010 36.0 Mean/median: 12.4/10.6 Interestingly, the lowest 2 Jans and highest 3 Jans were -ENSO.

Today’s Euro Weeklies were better overall for E US, incl 1/12-18 Today H5: Yesterday 2m: Today 2m:

Just looking at the 8 cases that were during -ENSO (16, 22, 26, 33, 42, 44, 95, 10), the Jan SN mean/median rises to 12.8”/9.9”.

Thanks. However, when I did my estimates, I took into account that the 12/29 highs would be at midnight from there through OH/IN, ATL, to BRO, etc. I did the same for 12/28 highs in the Plains/upper MW and the 12/30 highs in the NE. If anything my 31 est. for 12/28-31 is slightly high. I est. 33, 26, 29, 33 for 12/28-31. For similar reasons, there were 11:59PM lows to take into account, which I did.

I see ~no chance for Dec ‘25 to come in warmer than Dec ‘39’s 37.7. Through the 27th (last widespread US warm day), MTD could rise to ~38.2. But 12/28-31 are progged to avg ~31. That would bring the full Dec back down to ~37.2.

I see ~no chance for Dec ‘25 to come in warmer than Dec ‘39’s 37.7. Through the 27th (last widespread US warm day), MTD could rise to ~38.2. But 12/28-31 are progged to avg ~31. That would bring the full Dec back down to ~37.2.

-NYC now up to 7.2” snow this month, snowiest since Jan of ‘22. Thus, using stats @bluewaveand @donsutherland1got me informed about, I’m now forecasting a season total of 30” min., highest since at the very least 20-21. -NYC headed to ~5 BN this month, coldest vs norm since Mar of ‘15!

La Guardia was at 4.1” as of 7AM. So, all NYC area official reports are now above 4”.

Anyone see LaGuardia’s total? Other than that, I think every NYC official station got 4”+. C Park was up to 0.49” liquid equiv as of 7AM. Was that that far off? How much liquid was forecasted?

They got an additional 0.20” of liquid equivalent 7-11PM. As of 7 PM, they had had only .01”.

Today’s Euro Weeklies, which are overall fairly similar to yesterday, still have that new +PNA in the means for 1/12-18: This setup continues more strongly into the subsequent week, 1/19-25, than was seen yesterday:

Things are looking up for Jan just as our buddy Buc-ee is doing:

Natural has us up 4% today. This is one of the reasons: The 12Z GEFS has this at the end: more W coast ridging than prior runs along with a pronounced weakening of the Aleutian ridge: The result is an increasing hint on the GEFS of an Arctic high plunging down ~Jan 9th-11th along with a second one to follow: The SW Canadian air that might be brought down then is very cold:

BAMwx video update from Michael Clark this morning:

We’ll see. But keep in mind that: -Jan 22 had +NAO/+AO -This was the PNA forecast as of 4 years ago today through 1/9/22: it was for still -PNA as of 1/9/22. It turned out that 1/9/22 was the first +PNA day of a 38 straight day +PNA. So, GEFS 4 years ago was blind to its start even as late as today: - Today’s GEFS PNA forecast is eerily similarly maintaining a -PNA: hmmmm Also, keep in mind that GEFS (and all of the major ensembles) have had a strong -PNA bias over the last 90 days:

Based on population weighted heating degree days, a good measure of energy usage, the Conus in Dec won’t be that warm at all! Pop weighted Dec temps are progged to come out to only ~1 F warmer than normal. My estimate is for Chicago to end up Dec 3 BN, Cinci 2.5 BN, Balt. 4.5 BN, Philly 4 BN, NYC 5 BN, and Boston 4.5 BN. Even the upper SE (NC) should come in slightly BN and then ~+1.5 at ATL. SL should be right at normal. DFW should be ~5 AN, DEN ~11 AN, Phoenix 6.5 AN, LA 3 AN and Seattle 4.5 AN. Based strictly on geographic area though, my guess is that the Conus will come out to ~3 AN for Dec (~1 BN E 1/2 and ~7 AN W 1/2) or ~37 F. If it comes out to 3 AN, that wouldn’t be anywhere near the records of 2023 (~5.5 AN or 40.0), 2021 (~5 AN or ~39.3 F) 2015 (~4.5 AN or ~38.6 F), and 2024 (~4 AN or 38.3 F). So, I expect Dec of 2025 on an aerial basis to come out ~3 F colder than 2023, ~2 F colder than 2021, ~1.5 F colder than 2015, and ~1.0 F colder than 2024. Also, 1939 was ~37.7 F. So, I believe that on an aerial basis that Dec of 2025 will come out no warmer than 6th warmest Dec since 1895. Also, it’s possible that 1957 and even 2014 end up warmer than 2025 if I’m a little too warm with my 37 F guess by, say, a couple of tenths, possibly dropping 2025 down to as low as 8th warmest. @TheClimateChanger

Thanks. Thus, we agree on aerial weighing. Do you agree that pop weighted would have been warmer in 2021?

Which avg Conus Christmas highs were warmer, 2021 or 2025? 1. Based on geographic area, I’d say 2025. Why? Because most of the W 1/2 including most of the Plains states as well as MO and much of TX were warmer in addition to much of the SE. Much of the NE to Ohio Valley/Michigan to Virginias/KY and much of the Midsouth were cooler. Interestingly, NYC and Chicago were about the same. 2. In terms of population weighted highs (energy usage indicator), I think 2021 was net warmer because of the high population of the NE to Ohio Valley to Michigan being warmer. 2021 forecasted highs: 2025 3:20PM EST temps:

78 was the high at SAV today. They’ve had 78, 78, and 75 the last 3 days. Torchy but no records, which are 81, 83, and 82. Most of their record highs in winter are in the low 80s as 70s aren’t at all uncommon. We still have 4 more days of mid to upper 70s to go before the bottom falls out. So, that would make 75ish+ 7 days in a row. Good job by the models with the warmth for a change! This is the first period they’ve done well since the week prior to Thanksgiving. They saw this coming pretty far out.

The best looking H5 map for cold potential for the E US in Jan on today’s Euro Weeklies is this one with a nice +PNA, which is for 1/12-18 (similar to yesterday): Just 3 days ago it still had an ugly -PNA: so there’s been a big change for an ens mean for a week long period Here’s today’s temp map for the same week (similar to yesterday): chilly but I fully expect this would turn much colder than this if the +PNA idea is right Here’s what the same week’s map had just 3 days ago, which is consistent with that ugly H5 then: