GaWx

Also, Dec of 2016 had a +WPO and Dec of 2022 had a neutral WPO unlike the -WPO of Dec of 2025 fwiw.

Our airport had a low of 25 for the 2nd morning in a row. My lowest was likely ~30 vs 26.6 yesterday. But the freeze last night was radiational rather than advective/windy with a much longer duration of ~9 hours.

Thanks. That’s based on my 1st list, which is of those Decembers that had 1+ days dipping lower than -3.48. But those Decembers didn’t necessarily have a solid -WPO dominating through the entire month. One of those Decembers, 1996, actually averaged a +WPO overall. Also, 1983 and 1977 didn’t average a negative enough WPO. And there were a bunch of Decs left out of that 1st list that had a very -WPO with it dominating throughout but that didn’t have at least one day dip below -3.48 like 2013, 2010, 2009, 1995, 1980, 1961, and 1956 that make them good -WPO Dec analogs. OTOH, the 2nd list included some that weren’t -ENSO through the winter or at all like 2009, 1989, 1980, and 1956. In addition, 2005 and 1995 had a moderate or strong +PNA in Dec. So, what are we left with for the best analogs based on solid -WPO throughout Dec, -ENSO through the winter, and a moderate to strong -PNA in Dec? 2013, 2010, and 1961. Of these three, the PNA flipped to positive in Jan in 2014 and 2011 and to neutral in Jan of 1962. So, the closest -ENSO/Dec -WPO/Dec -PNA analogs are 2013, 2010, and 1961.

I’ll check now for December. These 9 were solidly -WPO Decembers dominating throughout the entire month: 2013, 2010, 2009, 2005, 1995, 1989, 1980, 1961, and 1956. Of these: 1) Cold in the S Plains? 2013, 2009, 2005, 1989, 1961 2) Near normal S Plains? 2010, 1995 3) Mild S Plains? 1980, 1956 So, strong -WPO Decembers leaned somewhat to the cold side in the S Plains, but only 5 of 9 averaged cold. It looks like this year may end up averaging near normal based on a cold 1st half and mild 2nd half. But we’ll see. PNA for these 9 Decembers: 2013: moderate -PNA 2010: strong -PNA 2009: weak +PNA 2005: strong +PNA 1995: moderate +PNA 1989: moderate +PNA 1980: weak -PNA 1961: strong -PNA 1956: weak -PNA So, PNA for these solidly -WPO Decembers is very mixed.

Well, as of Dec 13th, the MJO still hasn’t returned to phase 8! It was in 8 only Dec 3rd-7th. Dec 8th-13th have all been in very weak (essentially neutral) phases 5-7. I still think it has a good chance to get back into 8 very soon, but we’ll see:

The 12/13/25 WPO of -3.48 is the most negative WPO on any day in December since 12/25/1996! The only Decembers since 1948 with at least one day lower than -3.48 are: 1996, 1989, 1983, 1977, 1966, 1955

But the Euro Weeklies still look mainly mild in most of the E US S of the northern fringe with the torchiest still W of the E US.

I just took a walk in very refreshing and invigorating 40 degree single digit dewpoint air along with beautiful blue skies and light winds. I love this wx!

OHC has been rising sharply the last 30 days:

Yeah, unfortunately here’s the ugly truth for E US cold preferrers (NG is down another 1% today making it a whopping 26% drop from the peak 11 days ago): left graph has EPS HDD (latest out/0Z in purple); note the cliff dive it takes from today’s very cold 33 HDD, which is a whopping 10 above the normal of 23, to 12/18’s mild 18, which is 6 below the normal of 24! It later gets as low as 15 on 12/25, which is 10 below the normal of 25!

It looks like that’s the case (rotated quickly through and out) per 850 temps on the models: 7PM in degrees C last night near the coldest brrrrr! 1AM last night had already warmed some with coldest already rotating to E NC/VA: 7AM this morning had warmed a lot everywhere!

Indeed. The official RMM record always puts it in one of the 8 phases (6, 5, 6, 7, 7 per the bolded below for 12/8-12), but, regardless, this is about as bullseye/weak as you can get for a 5 day period: 2025 12 8 0.16185258 0.31161267 6 0.35113916 Gottschalk10_method:_OLR_&_ACCESS_wind 2025 12 9 0.23143651 0.18252292 5 0.29474986 Gottschalk10_method:_OLR_&_ACCESS_wind 2025 12 10 0.12193847 0.22910139 6 0.25953120 Gottschalk10_method:_OLR_&_ACCESS_wind 2025 12 11 -9.49310213E-02 0.16355878 7 0.18911207 Gottschalk10_method:_OLR_&_ACCESS_wind 2025 12 12 -2.23553125E-02 8.96196812E-02 7 9.23658386E-02 Gottschalk10_method:_OLR_&_ACCESS_wind https://www.bom.gov.au/clim_data/IDCKGEM000/rmm.74toRealtime.txt

MJO still hadn’t gone back into 8 as of 12/12 with it technically still in a very weak 7 per the record: so, 12/8-12 in very weak phases 5-7 essentially neutral with it not far from the center

No, I’ll pass lol. 26.6 is coldest I saw for here (at 7:40 AM) The official (airport) low was 25 as of 7AM.

Cold air (SE style) is always appreciated by cold weenies like me because heat/humidity are so dominant much of the year. I had an invigorating walk just after it went through here early this evening. It was still in the upper to mid 50s, but it still felt so clean and crisp due to the combo of the the wind and dewpoints plunging into the mid-20s! Dry cold gives me so much energy! We’d better enjoy it while we still have it. Forecast is for low 20s even down in this area! But there’s still a long ways to go with it still at 43.5 here.

Thanks, Mitch. For the MidAtlantic, I roughly estimate 55% AN vs 45% BN. So, quite mixed as you’re implying. Thus, the predictability for Christmas and other days nearby is pretty low.

Despite my more optimistic posts in recent days, I always still try to be objective and show everything, good or bad. The Euro Weeklies remain steadfast on a warmer than average SE and Mid-Atlantic westward/solid -PNA through almost the entire run. The torchiest still remains well to the west of the E/SE US thanks to occasional cool-offs likely largely related to CAD saving the day. The NE is not far from normal. It tries to cool off in general in the E US toward normal the last week (1/19-25), but it isn’t really exciting looking. I continue to hope that just like the models have performed in many cases for the last 3.5 weeks, that they keep busting too warm in the E US.

This has been going on a lot since the Nov 20th and earlier runs were too warm for Thanksgiving week in much of the E US.

Official totals: NYC 2.7” LGA 2.6” JFK 4.6” Newark 4.1” Islip 5.8” Upton 7.3” Based on these numbers, this storm on its own is bullish for the rest of the season there imho.

Anything to keep any torch short-lived rather than long-lived would be a win for me. Considering that the SE will have had a very enjoyably cold dominated 11/27-12/16: IF the SE can somehow manage for 12/17-31 to be only slightly warmer than normal thanks largely to cool wedges, I’ll consider it a win. Models are already significantly colder than they were just a couple of days ago for this weekend (12/20-1), which is continuing the trend of them being mainly too warm since ~Nov 20th. Is this going to extend this too warm trend through 12/21? If so, can we even trust the longer range of the ensembles? Fwiw, the 12Z GFS has 4 warm periods but all last only ~24 hours with the cool to cold days at least as prevalent.

So, your high end of 25” is near my new low end as I’m essentially 25”+ for the entire season based on today’s storm (I had no prior prediction). Are you going to raise your prediction from your 15-25” range?

Plus the indicator benchmark actually has worked better for 3” (15 out of 15) than for 4” (14 out of 15). Considering what you said (although I think the indicator has value if used correctly…this storm should more than be enough) and that 3” actually has worked better, I feel that this should already be more than enough (and we still have half the month to go, besides) to consider this a bullish indicator for NYC’s coming Jan+ snowfall to be in the vicinity of or above the 30 year normal of 24” for Jan+. Thus, I’m now predicting NYC will have at the very least 21” from Jan onward on top of whatever the Dec total ends up at: Season…Dec NYC SN...Jan+ NYC SN 20-21…..10.5”….28.1” 17-18……7.7”……33.2” 16-17……3.2”……27.0” 10-11…..20.1”…..41.8” 08-09…..6.0”…..21.6” 05-06…..9.7”…..30.3” 00-01…..13.4”…..21.6” 95-96…..11.5”……64.1” @bluewave@donsutherland1

The 48 hour trend on GEFS has been to a -NAO. Keep in mind what we just saw for last week, when the Nov 28th forecast had a +NAO and it ended up as a strong -NAO. Dec 12th GEFS: Dec 14th GEFS:

Any chance LGA can beat 3.6”? If so, it would mean their heaviest single storm total in nearly 4 years (Jan of 2022) and heaviest in Dec in 5 years.

On Nov. 4th, I made airline reservations with some friends to arrive this morning at LaGuardia from Savannah at 11:14AM for my first NYC trip since the summer of 2011 and their first trip there ever. Due to unexpected issues that suddenly came up with my friends, we had to cancel the very next day (fully refunded back to CC immediately). This had been emailed to me from what I had booked: Sunday 14 Dec 25 Flight Information Delta Air Lines /Republic Airways Delta Connection DL 5603 Savannah, New York La Guardia, 09:05 AM 11:14 AM Terminal C It’s a good thing we canceled this trip because this originally scheduled departure of 9:05AM from SAV has still not taken off and as of now isn’t scheduled to depart til 12:30PM! SAV Airport info 2h 9m flight. 2h 9m LGA Airport info Savannah · Sun, Dec 14 Estimated departure 12:30 PM Originally scheduled departure: 9:05 AM 9:05 AM Terminal - Gate 9 New York · Sun, Dec 14 Estimated arrival 2:27 PM Originally scheduled arrival: 11:14 AM 11:14 AM Terminal C Gate 98