GaWx

@TheClimateChanger I had as you know estimated that the MTD mean would rise to ~38.2 F as of 12/27. However, I then estimated as you also should know a 31F avg for 12/28-31 allowing the full month to end up at ~37.2. But after seeing the image below showing the MTD was very surprisingly to me still up at 38.13 as of 12/29, I now see no way that it will fall back to ~37.2. I had also said I saw ~no way that the full Dec would be warmer than the 37.75 of 1939. Now with this updated info, I can no longer say that as it looks like it will be a close call to 1939.

Hey Chuck, I’d say no. It’s hard for NG to bake in an extreme that’s essentially in fantasyland/during when model skill is pretty limited. So, I feel confident that it would rise substantially in advance of the very cold should it actually start to show up in late week two of the EPS and GEFS means or even in week 3 of the EW/ext GEFS in the bulk of the E US. However, even if that were to occur, there’s the possibility that it could fall a good bit more before the extreme cold shows up and prices start to rise. The ensemble mean HDDs continue to drop. The 18Z GEFss lost a whopping 14 HDDs vs the 12Z! But even though HDDs keep dropping, the trajectory continues to show a sharp climb late in week 2 to NN:

Folks, I recommend that snowman and others not look at the Euro Weeklies today. I’d instead go outside and enjoy the fantastic Canadian air! And Happy New Year! May 2026 be dominated by more Canadian air! Keep in mind that the EW are essentially the extended 0Z EPS. The 12Z EPS trended better with the western ridge and that won’t be reflected on the EW.

Excellent succinct summary! But there’s a typo as you meant Jan of 1976 as opposed to 1977. Also, Jan of 1975 phase 6 was almost as cold. By the way, I calculated the anoms based on GSP because that was near the center of BAM map’s coldest. Other areas would vary of course. I’d still much rather have moderate to weak 8-1-2 as I said for the E US as a whole.

Bump for @TheClimateChanger Do you have an update of Dec through the 30th? TIA I realize that with today still being colder than the avg of 12/1-30 by ~4 degrees per my guess, the final Dec update will be a little colder than 12/1-30.

The model consensus is suggesting a good chance for the Jan MJO to stay inside the circle for 20+ days. Only the following Jans since 1975 were on or inside the circle for 20+ days (note that it’s been 23 years since the last one due to the MJO avg amp increasing): 1977, 1980, 1981, 1982, 1994, 1996, 2000, 2003 Of these 8 Jans in the E US, 1977, 1981, 1982, 1994, and 2003 were cold while 1996 and 2000 were NN to slightly BN. Only 1980 was AN and it was only modestly AN. That one had its MJO the furthest right of the eight Jans mainly on or inside the circle with none in phases 7, 8, or 1. Of its 31 days, 25 were in phases 4 or 5. So, none of the 8 were anywhere near a torch. Here’s the cold composite for these 8 Jans with 20+ days on or inside the circle: Here’s the composite for the other Jans near the endpoints and in between: MJO outside circle 12+ days

That is a legit concern for me, too. The forecasted -EPO/+TNH cold pattern for the central US eventually looks great for cold domination prospects for the central US, much of the Midwest, and the N NE. But the biggest risk against sustainable cold is in the SE primarily and Mid-Atlantic secondarily, where the SE ridge may be too strong if the PNA in the means doesn’t go positive. This is very difficult to forecast this far out. Although I don’t like the warmer model developments of recent days for week 2 in the E US, my hope is still that the PNA in the means will flip for Jan averaged out to match the 100% of -ENSO -PNA Decs since 1983-4 that went to a net +PNA for Jan. My other hope is that the 90 day -PNA bias of the GEFS/EPS/GEPS means that they’re currently off. The GEFS AO looks better for midmonth vs yesterday fwiw.

I’m enjoying the current cold and dry snap. I had two great walks in the Canadian air the last 2 days and expect another one today. The area got down into the high 20s for the low, not far from the 25 coldest so far. Keep in mind that as of just 10 days ago, this cold snap was nonexistent on the models! So, I consider it a bonus to enjoy.

Thanks, snowman. One of the favored analogs has been 2021-2. This was the GEFS PNA forecast 4 years ago today through Jan 14, 2022: it showed the PNA turning positive, which it did but the mean wasn’t positive enough for midmonth: To compare, here’s today’s GEFS PNA forecast, which is clearly going in the right direction at the end but still isn’t then yet a +PNA. Note the wide spread of the members, however:

Natural gas, which usually drops when the high pop. centers of the NE US and Midwest look warmer in the 2 week forecast, is down >4%. The forecasted -EPO/+TNH cold pattern for the central US eventually looks great for cold domination prospects for the central US, much of the Midwest, and the N NE. But the biggest risk against sustainable cold is in the SE primarily and Mid-Atlantic secondarily, where the SE ridge may be too strong if the PNA in the means doesn’t go positive. This is very difficult to forecast this far out. Although I don’t like the warmer model developments of recent days for week 2 in the E US, my hope is still that the PNA in the means will flip for Jan averaged out to match the 100% of -ENSO -PNA Decs since 1983-4 that went to a net +PNA for Jan. My other hope is that the 90 day -PNA bias of the GEFS/EPS/GEPS means that they’re currently off. The GEFS AO looks better for midmonth vs yesterday fwiw: Yesterday: Today:

Watch out for potential major Arctic plunges week of 1/19-26: this was released on Tue 12/30.Exclusive Weather Updates from Vaisala/X Weather & The Weather Co.Brad Harvey, senior operational meteorologist at Vaisala, says that the forecast for the 6-to 10-day period features much-above-normal temperatures from the West to Texas. Highs are forecast to reach the 50s in Denver, 60s-70s in Dallas, and 70s in Houston. The Midwest and East are forecast to be drier than normal thanks to rounds of high pressure migrating southward from Canada. The forecast is near normal for temperatures in the Upper Midwest and below normal in the East. Risks are mixed for the Upper Midwest, where our forecast takes the middle ground between the warmer GFS and colder ECMWF solutions. Meanwhile, warmer risks in the Rockies are associated with downslope flow, while the Great Basin could be colder under high pressure. The models have lacked consistency in both the 6-to 10-day and 11-to 15-day periods. “The GFS EN projects a –PNA pattern, while ECMWF trends toward a +PNA. Neither of these solutions are given higher favorability, with our forecast featuring a round of above normal temperatures in the Eastern Half and belows emerging late in the Midwest.” For more information, go to https://www.xweather.com/weatherdesk. Mickey Shuman, a senior meteorologist with The Weather Company, tells us that for most of next week, the Pacific pattern will reverse, helping to drive mild Pacific air into much of western and interior North America. However, a west-based -NAO block will impede the advancement of the mild air into the East. By the 11-to 15-day period, mild Pacific and maritime Atlantic air will overspread the entirety of Canada, essentially shutting down the risk of any major cold air intrusions, such that most of the CONUS moderates and ends up on the warmer side of normal, supporting a prolonged stretch of lower-than-normal GWHDDs. That being said, an emerging +PNA signal also suggests that there won’t be a major or sustainable warm-up and that some seasonably cold air attempts to expand south and east later in the period. The bigger story is the potential pattern change for the middle to end of the month, which could lead to noteworthy cold Arctic blasts over the eastern two-thirds centered on the week of the 19-26th. For more information, go to https://www.weathercompany.com/

I did the analysis of the 15 Jans with phase 6 during La Niña (1975-2025) Year….# phase 6 days…avg anomaly 1975…3…-8 1976…13…-9 1989…3…+8 1999…3…+2 2000…3…-4 2006…6…+3 2008…3…+8 2009…6…+1 2011…12…-7 2012…19…+1 2017…2…0 2018…3…-2 2021…8…-1 2022…4…-9 2025…2…-5 ————— 91 total days that averaged ~-2 3 MBN 3 BN 6 NN 1 AN 2 MAN BAMwx said that the phase 6 MJO/-AAM analogs had this at ~-6 to -7. So, I believe based on the above analysis that this is a good bit overdone and should be ~-2. Granted, it came in cool on average with the -2 anomaly, which to me is admittedly a bit counterintuitive. And 1975, 1976, 2011, and 2022 came in quite cold during their Jan phase 6 days showing it would be doable. But one can see that only 6 of the 15 (40%) Jans during phase 6 were in BAMwx’s cold vicinity. So, I’d still much rather it go 8-1-2. Any comments? @donsutherland1@bluewave

Thanks for clarifying for us. My bad for misunderstanding what they meant by “0-2.5% significance”. So, it sounds like they’re saying that the chance that the warmth in the E US is due to randomness is only 2.5% or lower. Do I have that right? That would make perfect sense and sort of jibes with @cny riderand my original thinking.

Actually, I think it’s the opposite because the strongest warm anomalies are in the E US though admittedly I don’t know why it shows that as “0-2.5% significance”. That doesn’t make any sense as it should be the opposite!

I love the SE brand of cold. I’ve had more than enough mild after 7 days straight of torchy and sweaty 73-80. Thank goodness a return to a long torch isn’t in the forecast. I’m hoping for mainly BN to NN with low dewpoints (sub-45 is best) til further notice! Highs of 65 or lower other than a few low 70s scattered in and lows mainly in the 30s-40s. This is best for walking.