GaWx

0Z GEFS through 1/11 only: less than prior 2 runs Edit: keep in mind there’s also IP/ZR in addition to this

0Z Euro for Jan 10-11:

0Z UKMET like the 12Z UK/Euro is totally dry for 1/8-10 over the SE.

A NW trend is common and it coincides with the cold bias of most models in the E US. If I were betting, I’d bet on it most of the time. The cold bias leads to teases for the Deep South due to tracks too far SE that usually don’t verify. There are many more teases than the actual rare wintry precip events for down in this neck of the woods. When they do occur, they’re often just a T. That’s why I’ve said most likely nothing or at most a T for this event for this area. This keeps me grounded and keeps disappointment when it does the normal and doesn’t occur minimal at worst. The reason for the cold bias of models is debatable but some pro mets believe it is due to the very warm west Pacific and the models not handling it well.

The 18z Euro AI based on 850s (mainly near +2C), 1000/500 mb thicknesses (mainly ~550 dm during bulk), and a lot of qpf (~1”) appears to give ATL mainly IP and ZR (~0.95” liquid equivalent) assuming it remains <32F along with some snow near the end (~1/2”). Model says Atl-AHN will be close to 32 with 34 max.

18Z GFS precip types for 1/10-11: qpf: ATL to CAE: mix with mainly ZR (~0.5-0.7”) and ~1” snow/IP

No need to worry. Our area will most likely get either nothing or just a trace no matter what the wintry form. 150 years of weather history tells me that getting measurable wintry here is typically very difficult. The models sometimes tease us and more often than not end up as nothing. More recently, we’ve not even had a T of wintry in 7 years (longest wintry drought at least back to 1880s). Measurable since 1990: 3/93 light snow at end (from “Storm of Century”), 2/96 (light snow from upper low), 2/10 (rain changed to snow at end), 1/14 (light ZR and IP), and the big one, 1/18 (ZR, IP, SN). So, 5 times in 34 winters or once ever 7 winters since 90-91. A trace would be a reasonable goal with only the HOPE, not the expectation, of more. I’m actually not expecting anything per normalcy. But that doesn’t mean I don’t hope because at some point it will finally happen again.

12Z EPS snow through 1/11: similar to slight decrease This was 0Z through Jan 11th: Comparing the above map to the new run (12Z) below through Jan 11th shows similar in some places and decrease in others: Full new (12Z) run: slight increase N GA/much of SC meaning an increase after Jan 11th there while fairly similar overall NC:

-12Z UKMET has no split flow and thus no wintry precip in SE -12Z Euro some changes but it’s fairly similar to last 2 runs in not having much wintry precip in GA/SC/NC outside of mountains through 360: 12Z Euro similar to 12Z UKMET still no H5 split flow providing moisture unlike Icon and CMC. 12Z Euro similar to UKMET has all H5 flow down to the Gulf coast at crucial time we’ve been following from WNW to W (dry) But 12Z CMC (like 12Z Icon) has dry WNW to W H5 flow only well to the north (still supplying the cold) while having moist WSW flow Gulf to Deep South (aka split flow) that flows over low level cold and thus wintry precip there:

It’s all just digital at this point. Nobody has anything yet. 12Z GEFS through Jan 11th: more than recent runs N GA to NW 2/3 of NC:

Indeed, here’s yesterday’s Euro Weekly map for 1/20-6 with a -PNA forming: Accompanying 2 meter temps: coldest shifts W/NW from E US to N Plains/Rockies/Midwest/Ohio Valley; note also that E US still mainly BN: After that week, the run has the subsequent 2 weeks NN in E US/no warmth.

12Z CMC has similar split flow to 12Z Icon leading to snow Gulf coast by Jan 9th like on Icon and GFS (CMC and Icon didn’t have this favorable of a split flow at 0Z):

12Z Icon very different from 0Z with split flow, which leads to snow Gulf coast 1/9: This leads to a very close call Gulf coast 1/9:

12Z GFS: very close in this area on Jan 10th: near freezing at sfc 1PM with cold NNE sfc winds, 850 temp near 0C, and radar showing sleet/mix falling then @Awesomesauce81might be interested

Stronger sfc high to the north on 12Z GFS. I’d like to see that continue to trend back stronger.

6Z GEFS mean not good at all for 1/10-1 (can kicking):

Compared to both the 0Z GEFS (quoted above) and the 12Z EPS, the 0Z EPS has a good bit less snow in most areas: Night night!

Indeed, I was just getting ready to post the 0Z GEFS snow, which I’d say has improved even more than marginally vs 18Z from Charlotte/Greensboro to N GA (~1” higher) and is also higher than 12Z/close to 6Z there: **Edit: However, this would still be can-kicking on the 0Z GEFS because the increases are for after 1/10-1. Next up: Euro ensemble. Then lights out! @SnowDawgto check what I added in an edit about the 0Z GEFS can kicking 1/10-1.

If the 1/10-1 Miller A were to not return, I’d consider it a classic case of can kicking unlike 1/6. I don’t like the trends at all but it’s still early enough for the trend to reverse and 1/10-1 to return as it has been only 12 hours on the GFS among others and that’s still 8 days away.

0Z Euro: not good for SE snow lovers as 2nd shortwave is so weak that there’s no surface low.

It would be nice if there could be a decent amount of cold surface high pressure maintaining itself to the north in the OH Valley but on the 0Z GFS it instead collapses rapidly when turning that way vs the respectable high that is retained there on the 12z (GFS run with big snowstorm): 12Z GFS: 1029 mb high 0Z GFS: only ~1022 mb high

You can see it visually in the HDD image below. Look how much less cold 1/10-12 have gotten since the 6Z GEFS run. For example, the 18Z run is a whopping nearly 5 HDD warmer on 1/11 vs the 6Z! Regardless, it is still quite cold and it can easily reverse back to how cold it was. With the combo of indices we have, I feel confident that the intensity and duration of the cold will maintain being impressive.

18Z GEFS snowfall: less vs recent runs for most and the run overall was significantly warmer

The 12Z Euro AI has qpf of 0.8-0.9” during 1/10-11 for much of N GA, NW 1/2 of SC, and much of NC. 850s never get above 0C meaning all snow (a whopping ~8-9”) at Rome, Gainesville, GSP, Charlotte, and RDU along with places in between, which would easily be the most widespread big SE snowstorm in many years. In ATL, AHN, AUG, and CAE, 850s do get just above 0C during a part of this implying sleet likely during part of it.

Per the avg of the last 12 runs of the 4 member CFS ens, part of the E US is forecasted to be near 10 F BN for the two week period Jan 8-21 and is forecasted to be the coldest area anomalywise on the entire globe through that period! These runs suggest these areas of the E US will be ~7 BN for Jan as a whole.