GaWx

Allan Huffman going with a cold January in the E US. I wonder if this is because of a prog for a very early SSWE followed by a lagged cold effect in Jan: I’d be more than happy with this. I’d love another cold Jan! Not having a warmer than normal La Niña winter in the majority of the SE including another cold Jan would be a victory!

Thanks for posting this. I wonder if Alan’s cold Jan is largely because of a prog for a very early SSWE followed by a lagged cold effect in Jan. I’d be quite content with this. Not having a warmer than normal La Niña winter in the majority of the SE including another cold Jan would be a victory!

Indeed, there’s a much greater % of the conus with BN vs AN in weeks 1-2 of Dec.

Thanks. This is what I was looking at directly from ECMWF rather than from WxBell and also this is strictly for Dec 1-21: still no prevailing +PNA Dec 1-7: coldest MW to Rockies vs mainly NN NE/SE Dec 8-14: coldest MW to N Rockies; slightly cold NE; NN SE Dec 15-21: slightly cold NE, NN SE

Today’s Euro Weeklies for Dec 1-21 are still showing consistent strong cold largely avoiding the E and especially SE due to a neutral PNA to -PNA not driving the coldest anomalies far into the SE. The Midwest to N Rockies are where the coldest anomalies remain concentrated.

AAM is still looking to go back to a solid negative next week and last for 2 weeks. However, afterward, this is showing a move back up closer to neutral for early Dec fwiw:

Natgas is up a whopping 5% due to increased late Nov-Dec cold potential.

The Earth’s average CO2 level was 333 during the very cold winter of 1976-7. That’s pretty impressive considering that it had risen from 285 in 1850. I’m assuming that the increase in sulfates was probably a big reason. To compare, it is now all of the way up to ~431!

This map gives a good perspective that shows the record cold was widespread from the mid-south to the SE US and with a few in the lower Midwest and also in TX although, indeed, none in the NE US:

Followup to the above based on lowest hourlies through 7AM (I’ll update this if any official lows turn out to be lower):These appear to be the lows along with the model that was closest out of the 11/7 6Z GFS/ICON/Euro runs and 11/7 0Z UKMET/CMC runs:SAV: 28/ICONNE ATL: 28/EuroGSP: 23/ICONCAE: 29/ICONCLT: 29/CMCRDU: 30/ICON, Euro, GFS tied-Avg of these: 27.8, which is significantly colder than my guess of 30.5 and lead me to be dead wrong with my prediction of ICON to be the furthest away!-So, although the CMC was closest to only 1 of the 6, it’s average of 28.5 followed by ICON’s 26.3 were closest to the 27.8 actual-UKMET’s 32.6 was easily the furthest-So, ICON, alone, was closest to 3 of the 6So, ICON and CMC did the best overall due to being the coldest while UKMET was the worst due to being the warmest

@donsutherland1put together and posted this excellent table in the SE thread that says a lot about how historic this cold is in the Deep South:

Thanks, Don! To add to this, today’s 28 F at KSAV (SAV airport) was colder than 78% of the coldest official Savannah lows for the ENTIRE November (records back to 1874)! The last time it was colder during the entire November was 2014. Even Hunter AAF base, which is ~6 miles to the SE (closer to the ocean), was able to have a low of 29! So, the ability of this windy freeze (as opposed to it being a radiational freeze) getting the cold all of the way to the coast was quite evident! Also, the official Jacksonville, FL, station (more inland airport) got down to 28! Closer to town lows were 30-32. It looks like various stations in Gainesville, FL, got down to 30-34. The official Gainesville (airport) got down at least to 32. I’m guessing its official low will end up at 31.

My city’s official low (KSAV) as of 7AM EST was way down to 28 F, which beats the 31 record low for the day (records back to 1874). Not only that but also: -last time it was this cold or colder this early in season was 1976 -colder than 78% of coldest for ENTIRE November -last time it was colder in entire November was 2014

This Euro Weeklies run verbatim looks to me like it may be closer to a neutral PNA than a -PNA for the avg of the 3 weeks and especially weeks 1-2 as 3 does look like it may be more -PNA (along with a -EPO, -NAO, and -AO): (not favoring the SE for intense cold and favoring the Midwest over the NE) Dec 1-7: Dec 8-14: Dec 15-21:

You can add Wilmington, NC to that record earliest snow. Their previous record earliest was also 11/12/2013.

The wind here has been crazy high. It was enough to blow over my trash bin on its side, which I don’t recall ever happening before!

WCS accidentally left out the SSWE of 11/30/1958 unless they don’t think 1958 counts as modern: https://www.researchgate.net/figure/The-SSW-and-SFW-event-onset-date-year-and-type-identified-in-the-NCEP-NCAR-dataset-The_tbl1_267063738

That -1.2 is the RONI daily equivalent value, not trimonth, and that seems legit. OTOH, the last released trimonth RONI was -0.78.

My niece in Emory area (NE Atlanta) reported snow flurries just before 5:15PM. She was so excited! Edit: Also two friends in different parts of Cobb County (NW of Atlantic) saw snow flurries/showers this afternoon…one said they lasted a couple of hours with it coming down “pretty good” for a few minutes

Euro Weeklies: coldest run yet for 1st 3 weeks in Dec for US overall. The maps don’t even have a speck of warmer than normal in the entire Conus except for S TX and S/C FL. Dec 1-7: Dec 8-14: Dec 15-21:

What has been the approximate range of total snowfall for Chicago, itself, so far? I know there’s a last gasp now near the shoreline.

ONI: -0.45 NDJ 2024 26.09 -0.53 DJF 2025 26.05 -0.59 JFM 2025 26.49 -0.38 FMA 2025 27.11 -0.18 MAM 2025 27.60 -0.09 AMJ 2025 27.72 -0.11 MJJ 2025 27.54 -0.11 JJA 2025 27.11 -0.19 JAS 2025 26.63 -0.32 ASO 2025 26.31 -0.45 ———— RONI: -0.78 NDJ 2024 -1.07 DJF 2025 -1.12 JFM 2025 -0.90 FMA 2025 -0.67 MAM 2025 -0.52 AMJ 2025 -0.49 MJJ 2025 -0.43 JJA 2025 -0.47 JAS 2025 -0.63 ASO 2025 -0.78 ———— So, RONI less ONI -0.33 RONI less ONI: NDJ -0.54 DJF -0.53 JFM -0.52 FMA -0.49 MAM -0.43 AMJ -0.38 MJJ -0.32 JJA -0.28 JAS -0.31 ASO -0.33 So, after slowly falling NDJ through JJA, RONI less ONI has bounced back some. ONI link: https://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt

Just out from LOT (11:37 PM): THE INITIAL PUSH OF SNOW THAT DROPPED VIS DOWN TO 3/4SM AT CHICAGO TERMINALS IS PUSHING SOUTHWESTWARD TOWARD KPIA. HOWEVER, THE NEXT BAND OF SNOW IS RIGHT ALONG THE LAKE SHORELINE AT THE TIME THIS DISCUSSION WAS PUBLISHED. CURRENTLY CONDITIONS AT CHICAGO TERMINALS ARE VFR, BUT WITH THE NEXT BAND ABOUT TO MOVE ONSHORE, THE TAFS WERE SENT WITH WORSE CONDITIONS DUE TO THE EXPECTATIONS THAT THINGS WILL DETERIORATE QUICKLY AFTER 06Z. THIS BAND WILL BE HAVE MORE VIGOROUS SNOW RATES AND STRONG GUSTY WINDS. LOW VIS IS EXPECTED, BUT MAY EXCEED EXPECTATIONS AND BECOME SUB-1/4SM. ADDITIONALLY, BUOYS HAVE ALREADY REPORTED GUSTS TO 31 KNOTS, AND WHILE 35 KNOTS IS IN THE TAF, IT IS ENTIRELY POSSIBLE THAT GUSTS TOUCH 40 KNOTS AT TIMES. IT IS POSSIBLE THE THE TEMPO FROM 06Z TO 09Z IS A HAIR LONG, BUT HAVE MODERATE CONFIDENCE THAT THERE COULD BE 3 HOURS OF REALLY INTENSE SNOW RATES. LOOKING AT REGIONAL RADAR, THERE IS A LONG LAKE ORIENTED BAND OFF THE WISCONSIN SHORELINE MOVING SOUTHWARD. THIS BAND WILL BE "ROUND 2" AS IT MOVES INTO ILLINOIS. THERE WILL THE EXPECTATION IS THAT THERE WILL PROBABLY SOME TIME OF "BREAK" IN THE INTENSE SNOW BEFORE IT MOVES SOUTHWARD (LONGER AT KMDW AND KGYY). CAN'T RULE OUT SOME QUICK VFR CONDITIONS, BUT FELT MORE PRUDENT TO LEAVE IFR/MVFR CONDITIONS FOR ONGOING SNOWFALL. NEVERTHELESS, A SECOND ROUND OF INTENSE LAKE EFFECT SNOW IS EXPECTED BEFORE DAYBREAK.

Fascinating very detailed update just a few minutes ago from Chi NWSFO explaining how difficult this forecast is:UPDATE ISSUED AT 944 PM CST SUN NOV 9 2025 HAVE EXPANDED THE WINTER WEATHER ADVISORY TO INCLUDE FORD AND BENTON COUNTIES, OTHERWISE NO CHANGES TO THE MANY, MANY HEADLINES IN EFFECT. ALSO, NO BIG CHANGES TO THE FORECAST GRIDS THIS EVENING. CONVECTIVE ALLOWING MODELS (CAMS) OFTEN STRUGGLE WITH THE EXACT DETAILS OF LAKE EFFECT SNOW, MUCH LIKE THEY DO WITH SPECIFICS OF SUMMERTIME CONVECTION. THIS WAS THE CASE THIS EVENING WITH THE MOVEMENT AND TIMING OF THE LAKE INDUCED/ENHANCED MESO-LOW, WHICH MOVED INLAND INTO NORTHERN IN HOURS EARLIER THAN MOST CAM GUIDANCE HAD BEEN INDICATING. THE FASTER AND FARTHER EAST TRACK OF THIS MESOLOW HAS RESULTED IN CAMS BEING WRONG IN THEIR DEPICTION OF A LARGE INITIAL WESTWARD SURGING LAKE EFFECT SNOW PLUME WELL INLAND INTO NORTHEASTERN IL LATE THIS EVENING. RATHER, THIS MESOLOW HAS BECOME NEARLY STATIONARY OVER NORTH CENTRAL INDIANA WITH A COHERENT, INTENSE SINGLE BAND OF LAKE EFFECT SNOW EXTENDING NORTHWEST THEN NORTH UP THE SPINE OF THE LAKE FROM THIS MESOLOW. SURFACE OBSERVATIONS DEPICT A SHARP SURFACE TROUGH EXTENDING NORTHWEST FROM THE MESOLOW ACROSS SOUTHERN LAKE MICHIGAN. THIS TROUGH AXIS HAS BEEN STEADILY MOVING SOUTHWARD DOWN THE LAKE, WITH THE STRONG LOW LEVEL NORTHEASTERLY FLOW IN THE WAKE OF THIS TROUGH HELPING PUSH THE LAKE EFFECT PLUME STEADILY WESTWARD. AS THIS TROUGH CONTINUES TO PUSH SOUTH OF THE LAKE, ANTICIPATE THAT WESTWARD PROGRESSION OF THE LAKE PLUME SHOULD PUSH IT INTO NORTHEAST IL BETWEEN 11 PM AND MIDNIGHT. CONFIDENCE IS LOW IN HOW FAR WEST THIS PLUME WILL GET INTO NE IL BEFORE BECOMING QUASI-STATIONARY FOR A TIME, THEN LIKELY SHIFTING BACK EASTWARD TOWARD AND ACROSS NORTHWEST IN MONDAY. REALLY NOT PUTTING A TON OF STOCK IN CAM GUIDANCE AT THIS POINT, SO ONCOMING MIDNIGHT SHIFT WILL BE NOWCASTING THIS BAND THROUGH THE NIGHT BASED ON OBSERVATIONAL TRENDS. NO CHANGE TO THE MAGNITUDE OF INSTABILITY, WHICH IS CONFIRMED BY A SPECIAL 0030Z VALPARAISO UNIVERSITY SOUNDING FROM THIS EVENING. STILL ANTICIPATE SNOWFALL RATES OF AT LEAST 2-3 INCHES PER HOUR WITHIN THE HEAVIEST ELEMENTS OF THIS BAND. DEPENDING ON HOW LONG THE BAND BECOMES QUASI-STATIONARY, IT IS CERTAINLY POSSIBLE THAT WE COULD SEE ISOLATED TOTALS PUSHING OR EVEN EXCEEDING A FOOT BEFORE THE BAND BEGINS SHIFTING EASTWARD. CURRENT TRENDS WOULD SEEM TO SUGGEST THAT LAKE OR COOK COUNTY IL COULD BE THAT WESTWARD TERMINUS THAT SEES SOME OF THE HEAVIER TOTALS. WHERE EVER THE BAND IS DURING RUSH HOUR TOMORROW MORNING, TRAVEL CONDITIONS WILL BE VERY DIFFICULT TO NEARLY IMPOSSIBLE. - IZZI

Any opinions about this, which suggests Greenland blocking throughout this winter? @bluewave@snowman19