raindancewx

January already looks like a much better month down here - seasonal snow levels and multiple systems coming through later in the week. My ACE to La Nina thing implied ~26 days in Nov-Feb would be 5F or colder than daily averages even after the late hurricane season activity. We've had 0. So either its completely wrong, or super back loaded. Right now we have a high of 41F forecast at the end of the week, which is 6-7F below avg, and a cold low is likely too. For all La Ninas since 1950, it's almost never out by more than 20% either way. Even getting to 20 cold days by Feb 28 would mean half of remaining Jan-Feb days will be pretty cold - very different from our +10F Dec and warm Nov. Analogs in the 6-10 day for CPC include 2018-19 and 2022-23 which are two years I expect to be become much better matches as the pattern progresses. There was quite a bit of activity by Kamchatka (Lows) in mid-late December, which coincides with stormier/cooler weather in the SW at 17-21 day leads. So we're on schedule in that week two January period.

My idea for December was a very cold and a very warm period - worked pretty well.

I'll go out on a limb and say that I expect a pretty wet period for a lot of the West in January. I believe that's part of the transition out of the current pattern. CFS is pretty wet nationally for the US - something like 2/3 of the country is depicted as wetter (and warmer) than last January currently.

Here is the warm up no one thought was real - definitely verified as a much warmer period.

Look familiar? This is Dec 1962, 1964, 1975, 2010 warmed up two degrees. Core heat Northwest, not Southwest. Core cold Lakes/Mid Atlatnic, not Northern Plains or New England. I just picked the best temp matches in the -PNA, -WPO, -NAO, -ENSO set. These are all warmed up by 2F - still supports my idea since Sep/Oct of cold eventually retrogressing to the West.

By the way - this is the -ENSO (La Nina/near La Nina), -PNA, -WPO, -NAO composite for December since 1950. Its very similar to the pattern this month, but less extreme. The pattern this month has the cold/warm areas in the same place, just need to add at least 4-6F to both the cold (colder) and the warmth (warmer). In the composite, January is still pretty cold. But you do see the cold retrogress hard to the West - in March. February is not coherent - its all over the place. -NAO if it continues becomes a pretty strong cold signal further west later in the winter, particularly Jan 15 and on.

Subsurface decay is way ahead of last year. Doesn't mean we go to El Nino. But the warmth below the western tropical Pacific is advancing east and toward the surface pretty steadily.

This is a look at what the month looks like to date. Had the right idea blending 2013/2024 - Jan 2025/2014 doesn't look too different from month to date, but there are hints of changes by Alaska. I don't think the overall look of the pattern will collapse for a bit. But positioning of the key feature will migrate slowly in January.

December is more or less going how I expected, although more extreme. It never really looked like some consistently super cold pattern. To me it always looked like a pretty cold start and then a much warmer push back. Most of the country may actually finish warm. Locally we've literally never seen temps over 65F from mid-Dec to mid-Jan, so this level of warmth is pretty historic here and definitely more than I expected. The Northwest is actually warmest relative to averages, which is not really consistent with -WPO, -PNA historically. It's just an ugly, unstable and volatile pattern. Record cold all month...oops My big theory theory is very simple: eventually La Nina Climatology kicks in. If you retain the cold in Canada, but add in the ridge over the Southeast in Jan and/or Feb and/or Mar, the cold will dump into the West eventually. Alaska and Western Canada are usually a good source region for us, especially if the La Nina / -PDO are to collapse late toward an El Nino or +PDO. I wouldn't be surprised if it happens a bit later than I initially expected though given how everything has gone to date.

I'm running +7 or +8 month to date here, while Boston is running -7 to -8 month to date...but we've still had more snow than Boston even with less precipitation and a warmer base climate. Really is a pretty weird pattern this month - everything is a bit off from normal flow and progression.

There is an old song that reminds me about winter in the Northeast. Any of you know it?' We met in the springtime when blossoms unfold The pastures were green and the meadows were gold Our love was in flower as summer grew on Her love like the leaves now have withered and gone The roses have faded, there's frost at my door The birds in the morning don't sing anymore The grass in the valley is starting to die And out in the darkness the whippoorwills cry Alone and forsaken by fate and by man Oh Lord, if you hear me, please hold to my hand Oh, please understand Oh, where has she gone to? Oh, where can she be? She may have forsaken some other like me She promised to honor, to love, and obey Each vow was a plaything that she threw away The darkness is falling, the sky has turned gray A hound in the distance is starting to bey I wonder, I wonder what she's thinking of Forsaken, forgotten without any love Alone and forsaken by fate and by man Oh Lord, if you hear me, please hold to my hand Oh, please understand

You guys should be excited. Philadelphia is going to get 3-5 inches of snow before the next few systems come in as rain, and then whatever happens in January-March.

CPC now has the 8-14 day period stormy in the Southwest, which is consistent with the storm timing at the 17-21 day lead I posted a while ago. Also, we have the big warm up coming as expected. If you remember, the Canadian showed the US not very cold for December, despite the big cold wave everyone knew was coming early month. So it looks like the model did a pretty good job. Longer term, the look over NE Asia right about now looks like a big high centered over the Plains and a potent low over the SW US or Northern MX in 17-21 days, roughly in the Dec 29/30 to Jan 2/3 window.

Nov/Feb/Mar

My assumption for winter was 2025-26 as primarily a blend of 2013-14 and 2024-25. The weighting will vary between the two by month, but December now looks pretty warm West (like 2024) and pretty cold East (like 2013). Will be curious on the exact splits, as that's likely the correct weighting going forward and the pattern should weaken and then change by month end. Southwest US warmest Novembers on record tend to follow the same pattern here. For New Mexico the warmth slowly diminishes in intensity after an early-mid Nov heat burst in the valleys (5,000 ft+) to 75F or so, until you eventually arrive at a seasonal or cool month in the late winter-spring transition. Our warmest Novembers here are 2017, 1995, 1949, 2021, 1999, 2020, 1954, 2007, 2012, 1965. 17-18 was never really cold, but it did go from no rain/snow for 96 days and warm, to a wet/cooler period mid-Feb to mid-Mar. Similar for 1995-96, 2021-22, 1999-00, 2020-21. 1949-50 was cold in Dec, same for 1954-55. 07-08 was cold Dec-Jan. 2012-13 was cold Jan-Feb - 1965-66 too. Since we didn't get the cold Dec here, almost all other periods following a super warm Nov are either very cold Jan-Feb, or Feb-Mar...so Feb is the signal.