GaWx

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.

I’ve been emphasizing how the Euro had 12/2-8 as much too warm not long ago. So, these outlooks are very far from being reliable. But at the same time I’d still rather them not trend warmer like most later weeks did yesterday. Aside: NG now -5%/low of day.

JB’s the only forecaster I’ve read even just talking about a potential SSW. What got us started today is purely in response to a supposed SSW JB’s been talking about for late month. Our reaction has been to downplay it as mainly baseless hype, which I feel is a good thing to do for the wx bb community to try to suppress the hype early on. JB with his E US cold bias in winter is not surprisingly using it to hype a potential cold Jan, colder than his own non-cold Jan forecast. I think it’s sometimes good to call him out because he’s the master of hyping cold potential whether realistic or not as many readers here likely aren’t as knowledgeable about his cold bias (which recently even he’s openly admitted to).

My own research of the last 65 winters found that the best chance for a major SSW is during El Niño/east QBO like last winter. Last winter had two. I’m hoping (not predicting) for El Niño/east QBO again next winter. The last four CANSIPS runs have been showing a Modoki Nino developing this summer fwiw. History says that if La Niña/west QBO like the current winter were to have a major SSW, it would likely occur late. And that’s a legit possibility from the data I studied.

I’m quite confident that having JB as their prime long range forecaster still helps boost the number of Weather Bell subs. If only he’d keep his self-admitted E US winter cold bias from tarnishing his outlooks/comments. I do give him credit for a +2ish Nov-Mar forecast for the big NE cities this year, his warmest final winter forecast of at least the last 10 years and very likely longer. I don’t consider +2 a torch but rather just moderately AN. But for him it’s a torch even though +2 would be cooler than last winter. What he seems to be doing currently though is to downplay his own overall AN forecast with chances for cold in Jan (colder than his Jan forecast). That’s typical of his style due to some combo of weenieness and wanting to keep the subs from dropping.

Sounds to me more like baseless hype than anything clearcut at least based on latest strat forecasts. Although this doesn’t mean it can’t occur, I don’t see any current clearcut indication for a SSW event later in Dec based on both the latest EPS and GEFS at 10 mb. EPS: mean close to normal for zonal wind 2nd half of Dec/1st half of Jan GEFS: zonal wind AN 2nd half of Dec and NN 1st week of Jan

NG is down another 3%, which is very likely indicative of an overall warmer E US mid-Dec forecast. Also, yesterday’s longer term Euro Weeklies run for late Dec/early Jan was warmer than Sunday’s run overall fwiw.

Some lows this morning: KATL 31; KSAV 34; KCHS 32; KGNV: 32 A cold day is in store for today, the coldest of the season to date with sluggishly warming temperatures thanks to a new supply of cold air that is bringing 850s way BN (as much as 16 C/29 F BN)! Please pin this and unpin Nov @jburnsor @buckeyefan1. TIA.

Latest CFS ensemble AAM is still positive late Dec/early Jan (avg +1 to +2) though not quite as positive early Jan as that of prior (+2 to +3): Latest: Prior:

Unless I missed something, this would be the first measurable snow at Charlotte in the first week of Dec since way back in 1971!

I thought maybe those, too. I told her that but she said they’re the size of a housefly. Maybe 1/4”. So they’re too small to be a cicada.

Does anyone have any idea what these are? My sis (in Atlanta) is asking me and I can’t tell from pics. She thought they were a bug but I’m not so sure. This one was in a spider web: These were in her garage (came off a car underneath where it was parked):

Traveled I-16 today from Dublin eastward. I saw a very large number of trees down on the sides with the heaviest concentration from ~10 miles E of Dublin to Metter in pockets. It was wild as I’ve never seen anything like it for so many miles (40-50)! This was from Hurricane Helene, which likely caused highest gusts in the 90s mph in this area and was a once in a lifetime tropical event of that strength in much of this area as a result of the combo of it coming ashore in FL as a cat 4, large size, and near record speed of movement. It was like a bunch of tornadoes over a 50 mile wide stretch! There were some cleanup crew trucks in spots.

No I don’t and yes I don’t trust the unreliable CFS. After all it still has an unrealistic record cooling from Nov to Dec in Nino 3.4 that no other model had in Nov. However, even though it could turn on a dime, I’d still rather the CFS show this persistent strong +AAM than show a -AAM. So, we’ll see if it happens to be “onto” something as opposed to “on” something. I did notice that the last 3 runs of the extended GEFS break down the SE ridge late month *fwiw* suggesting it may dominate for no more than 1-2 weeks.

Chris, IF the last few CFS ensemble runs were to verify pretty well, we’d be looking at a strong +AAM (El Ninoish) late in Dec and early in Jan. If so, any mid Dec SE ridge dominance could be shortlived:

Yesterday (12/1) had the first freeze at Gainesville, FL, (aka Hogtown) with an impressive 28. That’s 3 colder than KSAV’s coldest so far this season of 31. Those who follow Hogtown know that it can radiate with the best of the deep SE. @pcbjr

Natural gas is down 6% this evening, which is usually at this time of year indicative of reduced cold in the two week forecast, especially toward the end of week two.

Todays Euro Weekly at H5 for 1/6-12 looks pretty good: