GaWx

Ji, With it still being a solid La Niña on a RONI basis (was still -1.0 in Dec and is only slowly warming), wouldn’t a weak southern stream be favored much of the winter?

As I said, I think BAMwx is significantly too cold in the means (which is what their map is supposed to represent). That pink area of -6 to -7 in the SE is, in reality (based on actual data that I analyzed) more like -2 along with much variation. And I didn’t analyze it for the entire E half of the US, which would take too long. If I get time, I could add a city like Baltimore, however, just to get an idea for this forum’s area.

Again to make sure folks keep track of what Webb actually said, he never said “Modoki El Niño forcing”. He said this: “It’s really interesting to see that we have already pushed the Pacific mean state to something in between La Nina & a modoki/Central Pacific El Niño.” So, in between La Niña and Modoki El Niño is exactly what he referred to. Per his research, a Feb in that group tended to be cold. By the way, Dec came in at -0.98 on a RONI basis and the latest BoM still has Feb down to -0.6. So, Feb will still be La Niña in that respect, which I respect.

This is BAMwx’s image: see lower right…that coldest area over the SE is ~-6 to -7 F for Jan -AAM phase 6s: The following are results of my research, which looked at GSP, a station in that coldest (pink) area, during La Niña Jans on that lower right map: Niña Year….# phase 6 days in Jan…avg anomaly 1975…3…-8 M 1976…13…-9 W-S 1989…3…+8 M 1999…3…+2 M 2000…3…-4 W 2006…6…+3 S 2008…3…+8 S 2009…6…+1 W-M 2011…12…-7 W-S 2012…19…+1 W-S 2017…2…0 W 2018…3…-2 S 2021…8…-1 M-S 2022…4…-9 W 2025…2…-5 W W weak (mainly in or near circle), M mod., S strong 91 total days (big sample) So, not surprisingly, there’s a wide spread. But the overall avg temp. anomaly at GSP during La Niña Jan phase 6s over the last 50 years did avg out to -2 F, a bit counterintuitive. So, this tells me two things: - Any possible phase 6 this month won’t necessarily favor mild in the E US though the spread is wide and it could end up that way - BAMwx’s -6 to -7 area in the SE and that map in general is significantly too cold for La Niña Jan phase 6. Only 6 of the 15 periods (40%) were about as cold as BAMwx. But the 40% does show a -6 to -7ish phase 6 this month would be doable.

1. He’s a well educated and well respected pro-met who typically backs up his posts with hard data. So, one wouldn’t think he’d risk his reputation by being a baseless weenie. 2. Just to clarify, in nothing that I quoted did Eric explicitly say he expects to go into a “Modoki El Niño pattern”. He said: “we have already pushed the Pacific mean state to something in between La Nina & a modoki/Central Pacific El Niño.” Is that wrong? 3. What’s Roundy saying? 4. Otherwise, are there any other Mets making a call for Feb?

Thanks, snowman. Well, fortunately he’s a well respected pro-met who constantly backs up his posts with hard data. So, he’d know what he’s talking about and thus he has a ton of followers. He didn’t say anything about March, however. Just Feb. That being said, is he near perfect? Of course not as he’s had his share of busts. But who hasn’t? So, his and other takes are all we have right now to go off of this early from pros. I wouldn’t bet anywhere near the farm on anyone this far out, but this is very encouraging to read. Also, Ray is on a similar page. I don’t recall any pro met being down on Feb recently. But I could have missed somebody. Speaking of other takes, has the well respected Paul Roundy said anything definitive about Feb yet? If so, please post it. TIA. Edit: This may be related to Webb’s optimism. Look at the OHC sharp warming: And look at the rising AAM fcast from yesterday’s CFS:

Coldest Jan 7th+ for Chicago lows on GEFS runs thru today’s 18Z:1/2 12Z +251/3 0Z +256Z +2112Z +1918Z +15 So, the GEFS mean coldest low at Chicago on the 18Z is a whopping 10 F colder than it was just 18 hours ago and is actually now slightly colder than the 12Z EPS’ 17. The normal Chicago low is for then ~18. So, the source for potential cold in the SE has gotten sig. colder. That’s the point of following and posting these. This colder 18Z run was largely related to a stronger -WPO, -EPO, and -AO vs the 12Z.

For those who are hoping for a cold Feb in the SE US, Eric Webb just a little while ago posted these increasingly positive takes: “It’s really interesting to see that we have already pushed the Pacific mean state to something in between La Nina & a modoki/Central Pacific El Niño. Notice the recurrent appearance of westerly wind anomalies over the Western Pacific (warm colors). Unlike most Nina winters that usually end up being very mild in February, seeing this change in the base state already occurring tells me that this winter has a few tricks up its sleeves.” ———— “Fwiw, I separated winters that preceded cool ENSO (cold neutral or Nina) >> El Niño transition by “cold” and “warm” Februarys on the East Coast and looked at their OLR/convective anomalies in the Tropical Pacific IMHO, given how much the Warm Pool has already advanced eastward, this year is leaning towards the “cold” February group with more convective activity or -OLR anomalies (cool colors) over the tropical West Pacific and tropical North Pacific, with a slightly weaker and eastward shifted area of +OLRa (decreased cloudiness, warm colors) near the International Dateline.” ————— “IMHO, we have opened the door to the possibility of 2014 style Feb this year with how the low frequency state is evolving in the Pacific.”

For those who are hoping for a cold Feb in the E US, Eric Webb just a little while ago posted these increasingly positive takes: “It’s really interesting to see that we have already pushed the Pacific mean state to something in between La Nina & a modoki/Central Pacific El Niño. Notice the recurrent appearance of westerly wind anomalies over the Western Pacific (warm colors). Unlike most Nina winters that usually end up being very mild in February, seeing this change in the base state already occurring tells me that this winter has a few tricks up its sleeves.” ———— “Fwiw, I separated winters that preceded cool ENSO (cold neutral or Nina) >> El Niño transition by “cold” and “warm” Februarys on the East Coast and looked at their OLR/convective anomalies in the Tropical Pacific IMHO, given how much the Warm Pool has already advanced eastward, this year is leaning towards the “cold” February group with more convective activity or -OLR anomalies (cool colors) over the tropical West Pacific and tropical North Pacific, with a slightly weaker and eastward shifted area of +OLRa (decreased cloudiness, warm colors) near the International Dateline.” ————— “IMHO, we have opened the door to the possibility of 2014 style Feb this year with how the low frequency state is evolving in the Pacific.”

Coldest post Jan 6th at Chicago on GFS/GEFS thru today’s 12Z: 1/2 12Z +30/+25 1/3 0Z +29/+25 6Z +21/+21 12Z +22/+19 Same for Euro/EPS: 1/2 12Z +22/+22 1/3 0Z -15/+16 1/3 12Z +7/+17

Dec QBO falls some more to -26.92, the lowest on record in Dec (to 1948) vs 2014’s -25.38. This sets up the chance for a record in Jan, too, though 2015’s -26.7 likely will be close: https://psl.noaa.gov/data/correlation/qbo.data

Today’s ens MJO progs both later get into 6: inside circle 6 would be best for cold chance during ph 6 as just posted: also Jans with 20+ days anywhere inside circle have averaged colder than the others as I posted about before:

Well, as it turned out again using GSP, El Niño ph 6 near or inside the circle in Jan turns out to avg cold just like La Niña inside Jan ph 6: Phase 6 during Nino Jan 77 6-9, 11-13: -7, -4, -11, -7, -20, -15, -13 (-11 W) 78 4: -6 (-6 W) 80 31: -13 (-13 W) 83 10-1: +1, +3 (+2 W) 92 3-8: +10, +13, +8, +6, +2, +1 (+7 W) 95 28-30: +1, -6, -7 (-4 W) 98 1-3, 21-2: -12, 0, +6, -3, -3 (-2 M)(-3 W) 03 10-12, 23-5: +5, -6, -10, -16, -19, -10 (-4 M)(-15 W) 05 9-19, 31: +10, +11, +11, +18, +22, +7, -1, -2, -13, -15, -14, -1 (+3 M)(-1 M) 07 9-13, 15-6, 24, 26-31: -1, -3, -4, +5, +16, +21, +5, -3, -5, +5, -2, -15, -2, -12 (+6 M)(-5 W) 10 20-1: +15, +3 (+9 M) 15 9-14, 28-31: -8, -11, -10, -1, -1, -4, -3, -2, 0, -4 (-6 S)(-2 W) 19 2-3, 25-30: +10, +11, -4, -5, -3, +1, -3, -9 (+11 S)(-4 S) 24 24-7: +6, +17, +21, +12 (+14 S) So, there were 20 Nino Jan ph 6 periods: 10 W: 3 MB, 4 B, 2 N, 1 A; avg -158/36 = -4.4 for weak! 6 M: 1 B, 2 N, 2 A, 1 MA avg +43/27 = +1.2 for moderate 4 S: 2 B, 2 MA +19/18 = +1 for strong 81 days BN 39 NN 16 AN 26 -66 cumulative or -1/day overall but cold concentrated when near/inside circle (-4 there vs +1 outside) similar to La Niña! For La Niña, it was overall -2/day with it averaging -5/day near/inside circle and +1 outside. So, the BAMwx idea of a cold E US during ph 6 in Jan in -AAM works out only for weak/mainly inside the circle and Nino is similar.

As we look ahead to Jan, here’s the wrap for Dec MJO: the last 12 days (12/20-31), which covered the torch period, turned out to track in 7-6-4-3-5, not well predicted by the models and which is typically not a cold path and can easily be mild: The coldest day of the month in the E US was during phase 8 and phase 8 overall was the typical cold. It never was able to get into 1 and instead took a detour across eventually to 5! Nothing even close to that had been predicted. Remember all of those endless ph 8 progs?

As we look ahead to Jan, here’s the wrap for Dec MJO: the last 12 days (12/20-31), which covered the torch period, turned out to track in 7-6-4-3-5, not well predicted by the models and which is typically not a cold path and can easily be mild: The coldest day of the month in the E US was during phase 8 and phase 8 overall was the typical cold. It never was able to get into 1 and instead took a detour across eventually to 5! Nothing even close to that had been predicted. Remember all of those endless ph 8 progs?

The reason for these Chi coldest of run posts is because of it being a source region since a lot of SE cold travels from that area. It’s extremely hard for the SE to get colder than Chi (outside of mtns) as the air traveling from there modifies as it comes SE and even more w/o snowcover.Whereas the 0Z GFS suite stayed the same (quite mild) as the 12Z despite the Euro suite getting sig. colder post Jan 6th, the 6Z GFS suite did trend a notable amount colder even though it’s still mainly mild (normal lows upper teens) (ens means are the most important that far out) Coldest post Jan 6th of GFS/GEFS:12Z +30/+250Z +29/+256Z +21/+21

Followup: 0Z vs 12Z Chicago lowest min (F) Jan 6+: Euro: -15 vs +22 EPS: +16 vs +22 GFS: +29 vs +30 GEFS: +25 vs +25 So, whereas Euro suite is colder, GFS suite is unchanged

ATL 15 coldest winters since 1950-1/SN 1957-8 2.7” incl IP 1960-1 0.1” 1962-3 T + major ZR 1963-4 3.6” 1965-6 0.7” 1967-8 4.2” + major ZR 1968-9 2.2” 1969-70 0.6” 1976-7 1.0” + ZR 1977-8 0.3” 1978-9 4.6” IP + major ZR 1981-2 7.7” incl. IP + ZR 1983-4 1.3” 2009-10 5.3” 2010-1 7.1” Avg 2.8” SN/IP + ~avg ZR 2.8”/1.9” = 1.5 times the 1.9” normal ————— Mild winters with 2”+: only 5 (~20% of them) 1951-2 3.9” 1990-1 2.1” 1991-2 5.0” 2001-2 4.6” 2017-8 4.7” NN to cold winters with 2”+: 26 (~50% of them) NN and BN similar chance for 2”+ So, for ATL, having a mild winter (2+ F AN) significantly cuts down on the chance for normal SN. But NN doesn’t at all. Keep in mind that often much of ATL’s snow in a season comes from just one storm.

ATL 15 coldest winters since 1950-1/SN 1957-8 2.7” incl IP 1960-1 0.1” 1962-3 T + major ZR 1963-4 3.6” 1965-6 0.7” 1967-8 4.2” + major ZR 1968-9 2.2” 1969-70 0.6” 1976-7 1.0” + ZR 1977-8 0.3” 1978-9 4.6” IP + major ZR 1981-2 7.7” incl. IP + ZR 1983-4 1.3” 2009-10 5.3” 2010-1 7.1” Avg 2.8” SN/IP + ~avg ZR 2.8”/1.9” = 1.5 times avg ————— Mild winters with 2”+: only 5 (~20% of them) 1951-2 3.9” 1990-1 2.1” 1991-2 5.0” 2001-2 4.6” 2017-8 4.7” NN to cold winters with 2”+: 26 (~50% of them) NN and BN similar chance for 2”+

That all looks pretty good at H5. But keep in mind that the Midwest only barely cools back down to NN briefly at best during these periods on that Euro run with AN dominating. And the GFS never even gets down to NN. Hopefully, the Euro and especially the GFS will cool off substantially on the ground in the Midwest as we get closer just as occurred for as recent periods as 12/28-today.

12Z Euro/GFS coldest low at Chicago 1/6-1/18: 22/30 12Z EPS/GEFS coldest low at Chicago 1/6-18: 22/25 Normal low 20-18 Not good for SE cold prospects. So, hopefully they’re going to turn out way too warm like 12/28-1/1 and earlier periods did. We’ll see. If not, it’s going to be very hard for the SE overall to get substantially cold before 1/20. Those 90 day bias maps had Chicago too warm by 4 F for the 11-15 fwiw:

Dec ‘25 will end up cooler than +3.9F once Dec 29-31 are added. Why? Because Dec 29-31 averaged NN to slightly BN vs 1991-2020 climo overall based on my rough est. That could be as cold as ~30 for those 3 days. So, the question isn’t if it will end up cooler because it has to based on the above. The question is how much will it bring down the +3.9. Roughly, you’d be adding a 10% weighting with as cold as ~-1 (based on 1991-2020 anomaly) to a 28 day of +3.9. That would come out to ~+3.4 IF the last 3 days were really -1. If it goes back down to ~+3.4, then it could also end up cooler than 1939, something @TheClimateChangerand I have been discussing. Even if Dec 29-31 averaged near 0 anomaly, that would still bring Dec as a whole down to +3.5, still quite possibly cooler than 1939 in the absolute and definitely much cooler for the anomaly vs appropriate climo for each period as 1939 was >+5.5. Also, 2015 may turn out warmer. So, 2025 could come in 6th or so. This chart only goes through 2021: Edit: note that per this chart that 1939 was >+5.5 F vs its climo and 1957 was ~+3.9. So, 2025 anomaly also could come in cooler than 1957’s anomaly. So, 2025’s anomaly vs its climo could come in 7th.

Today’s EPS and CFS are also going to ph 6 mid Jan. BAMwx posted that phase 6 in -AAM during Jan has been very cold in the E US, with the most intense cold in the interior SE (see lower right in image just below), which to me was very counterintuitive. So, I needed to know the answer. Now it’s even more important to know as the move to ph 6 midmonth now has increasing model support. The following are results of my research done on Tue, which looked at GSP, a station in that coldest (pink) area, during La Niña: Niña Year….# phase 6 days…avg anomaly 1975…3…-8 M 1976…13…-9 W-S 1989…3…+8 M 1999…3…+2 M 2000…3…-4 W 2006…6…+3 S 2008…3…+8 S 2009…6…+1 W-M 2011…12…-7 W-S 2012…19…+1 W-S 2017…2…0 W 2018…3…-2 S 2021…8…-1 M-S 2022…4…-9 W 2025…2…-5 W W weak (mainly in or near circle), M mod., S strong 91 total days (big sample) ————— So, 15 cases of ph 6 during Nina Jans: 3 MBN 3 BN 6 NN 1 AN 2 MAN ——————— - These La Nina Jan results weren’t at all what I would have expected for phase 6, one of the 3 mild Jan phases in the SE averaged out over all years: - Though there’s not surprisingly lots of variability, GSP did average 2 BN. Before seeing BAMwx’s post I never would have expected this. However, it should also be noted that BAM’s -6 to -7 for GSP is at the same time significantly too cold. - Only 3 of the 15 Jan cases were AN to MAN: 1989, 2006, and 2008. These were all M to S intensity (intuitive). - So, none of the last 8 were mild as there were 5 NN and 3 BN (2011, 2022, and 2025). These also averaged 2 BN. The weakest 3 averaged a solid cold 6 BN. - Thus if phase 6 continues to look more likely for midmonth, it will be interesting to see whether or not the NN to cold dominance works out in the SE (and E overall by association), especially if the bulk of ph 6 turns out to be anywhere from inside the circle to near/just outside the circle. @donsutherland1

Yeah, the 12Z EPS gives me hope. About all we know with decent confidence based on model consensus is that there will probably be a 4-5 day long torch (sound familiar?) mainly mid to next week. That covers Jan 6-10. After that, it’s a crap-shoot. If the 12Z EPS were to verify well, then things could be getting more interesting starting the week after next regardless of what todays EWs showed. By the way, the EW is essentially an extension of the 0Z EPS.