GaWx

Today’s MJO through 12/10: tune in tomorrow to see what they’ll do 12/11-27:

So, now I can give you the answer Yesterday’s 2 week GEFS (through 12/9/25) was starting to loop in 7 through the end of the 2 week run: was it going to stay in 7 or was it going to go into 8? Here’s the much anticipated answer: it ended up doing just a small, quick loop in 7 but then it went a little ways into 8 on 12/11. But that little ways was enough for the moderate amped 8 to last 8 days (12/11-18), which alone would be enough for the longest Dec phase 8 since Dec of 1989’s 10 days and longest, period, since Feb of 2019’s 9 days. However, it then looped back into 7 a little ways 12/19-26 with it stalled at the end. Now my question is whether or not it would have gone back into 8: we’ll never know that far out on this run

The above noted colder GEFS trend for early Dec continued with the 12Z run.

That ext Euro phase 8 lasts 11 days, which would be the longest in Dec since 1975. I just hope it actually gets there and stays for awhile rather than curl back to 7 to stay.

1. No, ext for same run comes out a day later. —————— 2. GEFS 2 days ago: GEFS yesterday: gets to phase 8 five days earlier than any other GEFS as of then: GEFS today: curled back very slightly vs yesterday (E US cold lovers wouldn’t want a curl back into phase 7) but very similar to yesterday/look how different it is vs 2 days ago!

Yesterday’s Euro: phase 8 starts 12/14: Today’s Euro: phase 8 starts 10 days earlier, 12/4, (with a 6+day long phase 8 implied) although I’d want to make sure it isn’t curling back into 7 and staying there: last time Dec had a 6+ day long phase 8 was way back in 1995 (12/20-5):

Euro Weeklies 2m temps for 11/24-30 and this is before the very recent cooldown for early Dec: 11/17 run: 11/24 run:

The colder trend for early Dec is happening on all ensembles including GEFS: these are all for a week from today at 7PM: watch the SER disappear: @donsutherland1@bluewave

I’m wondering if despite the clear warming trend of the Euro Weeklies related to its insistence of a stubborn potent SER along with the current progged switch to a +AO if there’s lower than normal confidence due to a combo of the MJO taking a track that’s often cold (though far from always as we know) and the current very weak SPV, which typically takes 2+ weeks to bring the E US persistent dominating cold.

I didn’t pick up on this earlier and don’t know if anyone else posted this. Today’s GEFS has phase 8 starting on Dec 8th, which is about 5 days earlier than any other run:

Your post shows yesterday’s ext EPS predicting an 11 day long phase 8 for 12/14-24 averaging ~2.0 amplitude. The ext GFS is predicting a 12++ day long phase 8 for 12/13-24++ but with a much lower avg amp that with extrapolation would likely be headed to a sub 1.5 amp for the full phase 8 avg. Regarding the EPS prog, there hasn’t been an 11+ day phase 8 since back in Feb of 2010 (2/7-17). Regarding the GEFS prog of 12++ days, there hasn’t been a 12+ day long one since way back in Dec ‘75-Jan ‘76 (12/19-1/5)! There have been only two on record of 12+ days: the just mentioned one of 18 days and a 13 day long one 1/19-31/75. Also, the 15 long phase 8s (8+ days) have followed long phase 7s (9+ days) only twice out of the 15 cases although the two that did were two of the coldest. So, needless to say, I’m taking these very long phase 8 progs with a huge grain for now. Of the 15 long phase 8s at Baltimore, the ones averaging an amp of <1.8 (like GEFS has) were significantly colder in the E US on avg than those with an avg amp >1.8 (like EPS has). The GEFS-like sub 1.8 amp cases include the very cold outbreaks of Jan of 1985, Jan of 1988, Dec of 1989, and Feb of 2010 with 3+” snows (including historic snow in 2010) for all 4 in Baltimore for example. The other 3 sub 1.8 amp phase 8s had either BN (1) or NN (2) temps at Baltimore. So, even a GEFS-like moderate long phase 8 hasn’t always been cold at Baltimore but rather in most cases and with no mild cases. But half of the >1.8 amp long phase 8s were warmer than normal! So, if there’s actually a very long phase 8, I’ll be rooting for one closer to the lower amp of GEFS than the higher amp of EPS due to better prospects for cold per long phase 8 history.

There has been a +PNA in Jan for all 11 cold ENSO winters that had a -PNA in Dec since 1983-4: -1983-4: -0.31 to +0.97 -1984-5: -1.60 to +1.63 -1996-7: -1.23 to +0.63 -1998-9: -0.09 to +0.16 -2008-9: -1.41 to +0.61 -2010-11: -1.78 to +1.29 -2012-3: -1.01 to +0.55 -2013-4: -0.86 to +0.97 -2016-7: -0.35 to +0.28 -2021-2: -2.56 to +1.01 -2022-3: -0.66 to +0.22 ———— What kind of PNA are you expecting in Jan?

This isn’t a new report but I just saw it and it has the latest Jamaica death toll: Death toll from Hurricane Melissa rises to 45 in Jamaica, with 15 others still missingThe death toll is expected to rise, with officials still trying to reach two towns that remain cut off since the catastrophic Category 5 storm made landfall in western Jamaica on Oct. 28. Helicopters have been dropping food and other basic supplies in those two communities, said Alvin Gayle, director general of Jamaica’s emergency management office. He said the storm has displaced 30,000 households, with 1,100 people still living in 88 emergency shelters that remain open. https://apnews.com/article/jamaica-hurricane-melissa-haiti-cuba-killed-deaths-77db005a55d415ae84b74f6680769273

I took your advice to find out instead of assuming. Since he doesn’t post here, I knew I had to ask him how he’s done with snow in NM. His answer: We’ve done okay ish I would say overall, we have yet to have any snow though. Just had our first precipitation event since early October a few days ago. Earlier this year it snowed on my birthday so that was nice. Our last 4” winter storm warning worthy storm was back in 2015, tho Feb 2021 got close in a few spots. Any accumulating snow is a really big deal down in the Desert Lowlands & people go crazy over it here like they do in the southeast. The climatology here since the early 2000s is roughly about the same as places like Charlotte, NC. It used to snow a lot more here several decades ago but our average has cratered. ———— So, it wasn’t bad like I thought, but by no means has he been racking it up either. It sounds in between. He hasn’t gotten that much, but they normally don’t there.

I don’t think met. Eric Webb has been happy with how his abode in NM has done in recent years (since he moved there) based on his posts.

Check this out regarding 8+ day long MJO phase 8 since 1974-5: Fifteen 8+ day winter phase 8 periods back to 1974-5 in # of days, amp, (practical) # days of preceding phase 7; Balt snow/temps: -1/19-31/75: 13; amp 2.1; 3; 3.5”/MA -12/19/75-1/5/76: 18; amp 1.0; 2; 0.5”/B -1/27-2/3/76: 8; amp 2.3; 4; 1.3”/N -2/8-15/76: 8; amp 1.8; 4; T/A -2/20-28/1978: 9; amp 1.8; 3; T/B -2/17-26/82: 10; amp 1.1; 0; 5.2”/N -1/21-30/83: 10; amp 1.5; 0; T/N -1/12-22/85: 11; amp 1.6; 9; 2.8”/MB -12/31/87-1/7/88: 8; amp 1.2; 6; 4.3”/MB -2/21-29/88: 9; amp 3.2; 5; T/B -12/9-18/89: 10; amp 1.1; 4; 5.5”/MB -1/2-9/97: 8; amp 1.9; 6; 2.4”/MA -2/16-24/99: 9; amp 2.1; 4; 0.6”/B -2/7-17/10: 11; amp 1.7; 16; 19.6”/MB -2/15-23/19: 9; amp 1.9; 1 (5); 4.5”/A ——————— Analysis of above: - The # of days of phase 7 preceding these long phase 8 periods have a large majority of the time been <7 days (counterintuitive?). - Consistent with the great post today of @bluewave, look how sharply the frequency has dropped off: 5 in the 2nd half of 70s, 6 in the 80s, 2 in the 90s, none in the 00s, 2 in the 10s, and none in the 1st half of the 20s. -So, from 1974-5 through 1989-90, there was an avg. of 0.7/winter. But since 1990-1, there has been a mere 0.1/winter or only 1/7 the frequency! -But when they occur, they still have been leaning pretty hard on snow and cold based on Baltimore: Temps: MA: 2 A: 2 N: 3 B: 4 MB: 4 - So, twice as many cold as mild - Total snowfall 50.2” over these 151 days, which means an average of 0.33” per day. That’s almost 150% of the Jan-Feb 1974-2025 average daily snow of 0.23”. - So, although they’ve been much harder to come by, lengthy phase 8 periods remain highly desirable for a winter lover in the E US. @donsutherland1 *Edit 6:30PM: On average, the <1.8 median amplitudes of these long phase 8 periods have been colder and snowier than the 1.8+ amps: There were 7 phase 8 amps <1.8: -4 of the 7 lower amps were the only four MBs while all 4 of the A to MA were when the amp was 1.8+. -All but one of the 4”+ snows were during an amp <1.8.

Today’s Euro Weeklies aren’t what you want to see if you don’t want them to be warmer than yesterday: the most intense cold on the run is W and SW of Chicago and perhaps near ME. I personally hate them because the colder the better and I hate sweating in winter when I take my walks. Note that the warmest anomalies in the US are in the deep SE: Dec 1-7: very slightly warmer/strong SER: Dec 8-14: slightly warmer/stronger SER lingering: Dec 15-21: warmer/SER won’t give up Dec 22-28: SER finally weakened but slightly warmer NE vs yesterday Dec 29-Jan 4: SER staying weak but slightly warmer NE vs yesterday:

DJF MJO last 15 winters (2010-1 through 2024-5): # of days each phase *7: 286 days from 58 phase 7s or 4.9 days/phase *8: 95 days from 34 phase 8s or 2.8 days/phase 1: 76 days from 24 phase 1s or 3.2 days/phase 2: 96 days from 23 phase 2s or 4.2 days/phase 3: 167 days 4: 173 days 5: 212 days 6: 249 days ——————— Per the above data, the # of phase 8 days for the last 15 winters, combined, has been only 1/3 the # of phase 7 days. This was due to a combo of much fewer phase 8 periods than phase 7 periods (34 vs 58) and much shorter avg. duration for 8 vs 7 (~3 days vs ~5 days). So, there sometimes is a struggle in going from phase 7 to 8. The # of combined 8-1-2 days has been ~# of phase 7 days, alone! The coldest E US phases have been 8, 1, and 2 while the warmest have been 4-6 (see bottom). The # of phase 8-1-2 days, combined, has only barely been higher than the # of phase 6 days, alone! So, as we look at Dec MJO progs, keep in mind the relative difficulty in getting as many phase 8 days (as well as each of phases 1 and 2, for that matter) as phase 7 days (if any at all). Just because models suggest a 2+ week long phase 7 is very likely doesn’t necessarily mean the durations of each of phases 8, 1, and 2 immediately following will be anywhere near as long, if they even occur. Here are the 10+ day long phase 7s since 2010-1 along with the subsequent phase 8-1-2: - 1/14-30/13: 17 days followed by a combined 15 days in 8-1-2 - 2/19-29/2016: 11 days followed by a combined 10 days in 8-1-2 - 2/2-18/2018: 17 days followed by a combined 10 days in 8-1-2 - 2/7-21/2021: 15 days followed by 0 days in 8-1-2 and instead a combined 11 days in 6-5-6-7 - 12/19/2021-1/9/2022: 22 days followed by only 4 days in phase 8 before going back to 7; phases 7-6-5-4-3 then dominated the next 3.5 weeks. - 1/1-10/2023: 10 days followed by a combined 9 days in 8-1-2 - 2/16-28/2023: 13 days followed by 1 day in phase 6 and then right back to phase 7 for 5 more days…so, 19 days in phase 7 for all practical purposes…followed by a combined 19 days in 8-1-2 - 1/28-2/6/2024: 10 days followed by 2 days in phase 6 and then right back to phase 7 for 10 more days….so, 22 days in phase 7 for all practical purposes…followed by only 1 day in phase 8, which was then followed by a combined 31 days in 7-5-6-7-3-4-5-6 ——————— Analysis of the above: - Much more frequent 10+ day long phase 7 last 5 winters with 5 of them vs only 3 during the previous 10 winters! - The combined 8-1-2 duration was never longer than the prior phase 7 length (using the “for all practical purposes” phase 7 length in two cases). - Of the 8 long duration phase 7s, two (25%) of the following 8-1-2 periods lasted a notable length of 15-19 days and three (38%) lasted a mediocre 9-10 days. However, the other three (38%) were only a minuscule 4 or fewer days long (4, 1, 0) and these were all within the last 5 winters. - So, whereas there’s a decent chance to get a higher end duration of 15-19+ days in 8-1-2 following the upcoming 7, the chance doesn’t appear to be very high and the chance of getting only a very disappointing short period is probably at least about as high. - Thus, recent history tells us that the upcoming 2nd half of Dec MJO is practically un-forecastable as of now with dominance by the often cold 8-1-2 about equally as probable as a feared hardly any 8-1-2. @donsutherland1@bluewave ——————— Daily MJO: https://www.bom.gov.au/clim_data/IDCKGEM000/rmm.74toRealtime.txt

Holy cow! That 82 F at KATL is also the warmest so late in the season by 6 days! They missed the warmest for all of Nov by only 2 F! Here it wasn’t a record, but it was the 4th day in a row with low 80s. Bring back autumn! It will be arriving just in time to give us a cool Thanksgiving!

Hopefully the MJO won’t turn sharply left along the 7/8 border like these: Dec of 2014 was mild: Dec-Jan 2019-20 was mild:

Whereas there can be a lag, the diagrams by phase are based on concurrent temps. So, phase 8 being the coldest in Dec is based on temps during phase 8 being the coldest of any phase rather than with a lag. Perhaps, it’s phase 7 in some cases being the cold generator that takes til phase 8 to show up in the E US.

12/9-14/91 also was a mild strong phase 8 in the E US though it cooled afterward:

The Weeklies have it mainly mild in the SE first 3 weeks of Dec, not the NE, thanks to a SE ridge. Anthony asked where’s the warmth? The maps he posted had SE warmth.

You don’t see any warmth, Anthony?

Why? I’m not going crazy. We look at long range guidance ITT every day. This is mainly a long range thread. You just posted weeks 3-4, for example. I’d rather have the most up to date.