GaWx

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.

Per the avg of the last 12 runs of the 4 member CFS ens, much of the SE is forecasted to be near 10 F BN for the two week period Jan 8-21! The SE is forecasted to be the coldest area anomalywise on the entire globe through that period!

12Z Euro ensemble mean snow: pretty similar to GEFS Here was 12Z GEFS:

This is kind of an odd setup and would actually be an extremely close call on/near the coast on the 12Z Euro if it were to somehow play out closely to this: 850 mb temps several degrees <0C during start of precip and even the coast never gets close to the 0C line: 1000-500 mb thicknesses at start of precip well below the common 546 dm needed to support snow in SE as these are in the mid to high 530s and they actually drop from this point: Surface dewpoints well below 32 just in advance: But surface flow is then a warm SW flow that warms low levels up rapidly just in time: Clipper surface low coming down allows SW flow ahead of it on backside of Arctic high moving offshore, a pretty unusual setup with a low also in the Gulf: The qpf ends up too light (<0.15”) to allow the easily cold enough levels between 850 and 500 to have sunk enough to counteract the warming surface SW flow:

6Z GEFS mean:

0Z Euro ens mean: most areas have more than on 12Z with largest increase C GA/SC to 1.1-1.5” range with all of that falling starting 8 days from now; that’s a lot of snow showing up that far out for that area: @jburns@buckeyefan1please pin this thread

It looks like Dec NAO will probably come in moderately positive in the table…..~+0.6 to +0.8. Then we’ll have the very strong first half of Jan -NAO. It may be as low as -2 tabular equivalent. But then it should rise quite a bit per model consensus. However, Jan as a whole should still come out decently negative, possibly sub -1. If it were to end up lower than -1.11, it would be the lowest since the mid 80s! If so, Dec-Jan would average a weak -NAO with only Feb left. So, there’d then be a shot at a sub -0.25 NAO near a solar max though I wouldn’t bet on it as of yet.