GaWx

Thanks for posting that. This tweet was posted elsewhere and here was my response to the bottom portion that addresses the extremely unreliable late portion of the cherry picked WB 6Z CFS ens mean: “I’d be cautious with WeatherBell CFS maps as they are usually colder than the NOAA and other versions. Also, one run of the CFS ensemble (4 members) like is being shown here (6Z of today) is extremely low in reliability, especially for the period near the end of the run. They jump around a lot. BAMwx shouldn’t imo be showing something like this as it borders on hype. They said ‘The CFS weekly is on board as well with a monster Alaskan ridge stretching well up into the pole. (-EPO)’ as if it were a big deal. But they cherry picked an extra cold run of the very jumpy, unreliable CFS and a WB version (colder than other versions) of it to boot. Don’t get me wrong. I’d love nothing more than for something like this to actually occur. But I don’t like to see hype.” Here’s the insanely ridiculously unrealistic and highly flawed WB 2m temperature anomaly map for this 6Z CFS ens mean for Jan 9-15: -10 to -30F anomalies (also note the typical WB CFS relative warm spot in N Michigan that’s indicative of a WB CFS flaw)

Mitch, Here’s the new WB Euro ensemble mean at H5 for Jan: looks like typical Nina with Aleutian ridge, BN hts far N Plains/Rockies/extreme upper MW, hints of SE ridge:

In contrast to the above BAMwx tweet showing the extreme -EPO of the WB 6Z CFS ensemble mean, here’s the average of the last 12 CFS ensemble means at Tropical Tidbits for Jan 9-15 (caution still advised as it is for 5 weeks out and it is the CFS): still a decent -EPO but much more subdued than the WB 6Z CFS ens mean (531 dm at MN/Canada border): Now check out the accompanying TT 2m temperature anomaly map: nothing extraordinary at all in the US with NN to slightly BN in the upper Midwest Compare the above to the WB 6Z CFS ens that BAMwx just tweeted (just one run and WB version) mean for Jan 9-15: this would border on historic for much of the US, especially Midwest (516 dm at MN/Canada border): And the accompanying WB 6Z CFS ens mean of today 2m temperature anomaly map has insanely ridiculous cold throughout most of the US (10-30F BN lmao) with nearly -30F in the upper Midwest (note the everpresent cold spot near Chicago and relative warm spot N Lake Michigan/Michigan indicative of flawed WB CFS maps):

The bottom portion of the following tweet from BAMwx (referring to today’s four member 6Z WB CFS ensemble) is imho borderline hype. Going back a few years, BAMwx tended to overhype at times. I hope they’re not reverting back. Someone just posted this tweet in the SE subforum and here was my reply: “I’d be cautious with WeatherBell CFS maps as they are usually colder than the NOAA and other versions. Also, one run of the CFS ensemble (4 members) like is being shown here (6Z of today) is extremely low in reliability, especially for the period near the end of the run. They jump around a lot. BAMwx shouldn’t imo be showing something like this as it borders on hype. They said “The CFS weekly is on board as well with a monster Alaskan ridge stretching well up into the pole. (-EPO)” as if it were a big deal. But they cherry picked an extra cold run of the very jumpy, unreliable CFS and a WB version (colder than other versions) of it to boot. Don’t get me wrong. I’d love nothing more than for something like this to actually occur. But I don’t like to see hype.”

I’d be cautious with WeatherBell CFS maps as they are usually colder than the NOAA and other versions. Also, one run of the CFS ensemble (4 members) like is being shown here (6Z of today) is extremely low in reliability, especially for the period near the end of the run. They jump around a lot. BAMwx shouldn’t imo be showing something like this as it borders on hype. They said “The CFS weekly is on board as well with a monster Alaskan ridge stretching well up into the pole. (-EPO)” as if it were a big deal. But they cherry picked an extra cold run of the very jumpy, unreliable CFS and a WB version (colder than other versions) of it to boot. Don’t get me wrong. I’d love nothing more than for something like this to actually occur. But I don’t like to see hype.

Latest WB Euro for Jan (12/1 forecast) is similar in New England, slightly warmer mid-Atlantic/SE (+2.5F to 3.5F), and cooler Midwest vs prior (11/1): Latest: Prior:

This is from pro-met Brad’s email response: “Your ideas about model biases are generally true. The CAN EN (GEPS) is often cold biased, and this is especially the case in the West as you have noted. The GEFS is often cold-biased as well, but this has not been the case more recently. I think the maps and graph from DTN make sense from what I remember this fall. With that said, model performance in the fall can vary more than other times of year. This might be a function of tropical activity, which peaks in the fall, but also the changing of seasons itself. So in that respect, I probably wouldn't consider the biases from this past fall to be an indication of how models will perform going forward.” “While I can’t say for sure what caused models to be too warm this fall season, their handling of soil moisture might be a theory:” So, in other words, Brad is suggesting that we not count on the net warm EPS/GEFS E US day 6-15 model biases of this past autumn continuing into this winter.

My opinion on this: -Michael Clark clearly presents his thoughts in detail with solid reasoning, especially regarding the MJO and TPV. Well done. He’s hinting at a strong possibility of a cold Jan in the Midwest to interior NE though he didn’t know about the coastal NE and said (virtually) nothing about the SE. -Per his history, I don’t put him in the Bastardi category of being a strongly cold biased hypester by any means (exhibited by him talking about warmth Dec 10-25/30….Bastardi would unlike Michael gloss over the warmth and skip to the cold potential)..so a big positive vs JB -Per that same history though, my feel is that he’s probably still a bit cold biased though not as much as a few years ago when I first followed him. -My biggest disappointment is how much emphasis he puts on the typically highly unreliable CFS. He focuses on the 12/4/24 0Z CFS 4 member ensemble run. Although that’s much better than just showing a control run (something JB often does when it is very cold), it’s still highly unreliable. -Besides it being typically highly unreliable, the CFS (though it has backed away slightly) is still calling for a record rate of Nino 3.4 cooling of -0.8C from Nov to Dec to -1.0C and then -1.25C in Jan! No other model is anywhere close. That potential huge error makes me wonder if it is affecting the CFS in Jan. -I also don’t like to see his displaying WxBell CFS US 2 meter temperature maps. They’re usually several degrees colder than what the NOAA CFS maps show on avg in the E US and are messed up. He showed the very cold WB 12/4/24 0Z ensemble run for Jan, which is almost definitely colder than what that actual CFS run has. Also, the maps he showed had the ever-present cold spot in S Lake Michigan and warm spot in N Lake Michigan. -My overall feeling is to take this with a grain but hope he’s generally right for Jan and hope that the cold includes the SE/Mid-Atlantic/coastal NE with no blocking mean SE ridge.

So, I want to make sure that Webb, jconsor and Chris are on the same page. Jconsor said this based on what Webb said: “Per Eric Webb, the PDO has limited influence and limited usefulness for subseasonal predictability (especially in a winter like this with a strong Indo-W Pacific warm pool).” This is what Webb said: “Most people misunderstand the direction of forcing. Extratropical SSTs are mostly forced by atmospheric circulation anomalies, not the other way around. I.e. the -PDO’s contemporary correlation with things like the -PNA is more of a reflection of the -PNA pattern forcing the -PDO on interannual scales, not the other way around” Chris, do you agree with jconsor and Webb that the PDO actually has limited influence on the atmosphere? So, does this mean that the record -PDO we’ve been having, itself, has been having only minimal impact on the atmosphere? There seems to be a lot of disagreement about this among the meteorological community, which has been confusing to me over the last few years. I‘m just trying to learn. For example, I used to think that -PDO, itself, including the W Pacific marine heatwave E of Japan, tended to help force a -PNA/stronger mean Aleutian ridge/stronger than avg mean SE ridge. But in reality it appears that the 15N to 15S warm pool in addition to La Niña is what drives that pattern and not also the marine heatwave to the north/-PDO. Chris and Yaakov, do I have this right? So, if so, does following the PDO, itself, have much usefulness for seasonal predictions for, say, the US and the Atlantic tropics? If not, what’s the point with regard to forecasting mean seasonal atmospheric circulation in following the PDO index and the E of Japan marine heatwave?

So, would you agree that the warm pool is between 15N and 15S latitudinal range? I want to make sure I’m properly following along with you on the waters you’re focusing on. So, does this mean that the marine heatwave E of Japan is having minimal impact on the atmosphere?

-RONI for SON just came out at -0.80. So, on a RONI basis this event will end up with at least a solid weak La Niña peak. -ONI for SON: -0.24 -So, difference between RONI and ONI in SON was -0.56 (difference between -0.80 and -0.24) - Difference between RONI and ONI: MJJ: -0.60 JJA: -0.55 JAS: -0.52 ASO: -0.54 SON: -0.56 So, when I see an OISST and want to very roughly estimate the equivalent daily RONI, I’m currently subtracting ~0.55. The Dec. 1st OISST was -0.35. So, I have the current equivalent Dec 1st RONI near -0.90**(**Corrected for typo).

The record high is +15.62 (June of 1995). I give it about a 10% chance to be exceeded. If so, that would almost definitely be in Dec or Jan.

-Nov QBO (at 30 mb): came in at +13.78 (about as expected) vs Oct’s +11.64. -Based on historical patterns (back to 1947 on this table), either Nov or more than likely Dec will be the peak. Jan has only a very small shot to be the month of the highest as it will likely already be starting to fall then. Peak almost definitely to be from +13.78 to +15.6 with best guess in the +14s: https://psl.noaa.gov/data/correlation/qbo.data We very likely will have a solid -QBO next winter.

Lows in my area: coldest of season to date KSAV 27 KSVN 28 Some others: KATL 27 coldest of season KGNV 26! @pcbjr had the coldest of these four locations and coldest for Hogtown to date this season. Radiation capital of the deep SE!

I just took a walk in 33-34 temperatures. But I was dressed appropriately and the winds were calm. So, I enjoyed it! It was so peaceful with it too cold for others.

Thanks, Chris. Honestly, I’m still surprised to see there being so much EPS warm bias over the E US in the 6-15 over the last 90 days. It is even showing warm bias over the Great Lakes, where the mean ridge axis was:

Interesting! The DTN bias graphs for GEFS/EPS you linked me for days 6-15 averaged over the last 90 days are surprisingly showing a warm bias in the NE US. I wonder why. If I get a chance, I’m going to email my Maxar pro met contact. Maybe he can give me an update on the week 2 biases.

The cold E US bias is very well known because it is so obvious after analysis of numerous verifications and it has been going on for many years. I’m talking based on a compilation of all of the runs from every day for major cities throughout the US done scientifically by pro mets. It has nothing to do with cherry picking. If you still have any doubt, subscribe to Maxar. You and others would learn a lot from them. They have many pro mets on staff. Their forecasts always take these biases into account making them “bc” (bias corrected). They are not cold hypesters like JB nor cold Debby Downers. Maxar makes money off of their reputation for accuracy, not off of hype or down-playing. They forecast with emotion left out. Weenieism or emotional based bias is strongly frowned upon. When Chris and I talk about bias, we mean the average discrepancy between forecasted and verified actual.

In other words, the models have a cold bias in the E US. They adjust warmer more often than adjusting colder as we get closer. This has been the case for probably 8+ years. The CMC ensemble actually has had the coldest bias at 2 meters of the big 3. I used to subscribe to a company that analyzed biases in detail. That’s how I know this. The W US is a different story. The bias is much closer to neutral with a few cities sometimes actually showing a warm bias due to overdone W ridging/underdone W troughing.

The brand new Euro Weeklies (which start Dec 9th) are mainly warmer than yesterday’s run in the E US in week by week comparisons for the last 3 full weeks of Dec. They are all mainly only slightly AN (~+2 to +3 vs 1991-2020 mean) meaning they’re not showing a blowtorch and still may not fully negate the very cold early Dec if they were to verify well. The first 2 weeks of Jan in the NE US are about the same as yesterday and are NN.

1. The brand new Euro Weeklies (which start Dec 9th) are mainly warmer than yesterday’s run in the SE US in week by week comparisons. They are all mainly only slightly AN (~+2 to +3 vs 1991-2020 mean) meaning they’re not showing a blowtorch and still may not fully negate the very cold early Dec: 2. This 30 day map is reflecting a warmer last 3 weeks of Dec but also dropping a cold Dec 2nd:

Thanks for posting. A bit of caution is advised because of the individual weeks generating that cold overall Dec map. The only reason it’s cold for the month as a whole in much of the E US is the very cold 12/2-8. The three weeks after that are all mainly near normal in much of the SE. I’d take NN though. Much better than AN. Today’s run will be out pretty soon.

NG largely ignores the long range because it is so highly unreliable. That’s why it focuses on the medium range. It reacts very soon after when medium range runs, especially EPS and GEFS, are released.

Nov NOAA PDO just came in about where I expected (based on adjusting WCS’ PDO) at -3.24 (rise of 0.54 from Oct). This compares to the WCS’ Nov of ~-2.10. So, this is only the 2nd time since 1851 with three sub -3 PDO months in a row. The other time was in 1894 (6 months earlier that year than 2024). We actually only barely missed 7 months in a row of sub -3 as the last 7 have all been sub -2.90: -2.99 -3.16 -2.99 -2.91 -3.54 -3.78 -3.24 https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat Current daily NOAA PDOs are likely in the low -3 range. @snowman19

The NG market is now down a whopping 15% vs a week ago. I learned quite awhile back that this market is smart (as @Stormchaserchuck1knows well) and is thus a great barometer of expectations of temperatures in the E US in the decently predictable medium range. Being down 15% is saying a lot as regards how things looked in the medium range one week ago, when near term cold looked like it might last through the first half of Dec.