GaWx

Barney says hey to E NC: holy snowcover but very likely way overdone: single digits at 1PM? No, Barney, you’re being silly! GFS has a strong cold bias over fresh snowcover. Nothing new.

18Z GFS: Barney doing his cold thing at 2m and 850 mb. Preliminary maps showing the low over MX in combo with the cold may mean more suppressed than 12Z.

That doesn’t mean dry. It means drier than climo avg. for 2/17-23. For Marietta, it still is giving 0.70” (not dry at all but drier than climo avg of 1.1”).

Asheville is +9 for Feb 1-12. The forecast per the 12Z EPS mean (which is between the less cold GEFS and the typically colder GEPS) is for -7 the rest of the month. If the EPS mean verifies well, Asheville will end Feb very near average. I admit that the 12Z EPS mean may be overdoing the length of the BN to some extent. But fwiw, it literally has Asheville BN on Feb 14 and then the 12 day period Feb 17-28 implying high chances for a significantly longer than 4-5 day period BN. Here is the new Euro Weeklies (based on 0Z EPS) for Feb 17-23, coldest yet by a good margin: that’s ~11BN for Asheville. The entire SE other than FL is BN even for mid-Jan: Feb 17-23 qpf: keep in mind that NN or even slightly BN is still pretty wet in mid to late Feb: 0.85-1.5” NW to SE in much of GA/Carolinas (ATL/Charlotte 0.85”; Triad/Triangle 1”, Augusta/CAE/ILM 1.2”; CHS/SAV 1.5”)

The models remain unanimous with a low of sub -5 AO on/near Feb 15th. Below is the latest GEFS. Today (2/13) it was at -3.7, which is actually lower than the -3.25 this chart shows. That gives me extra confidence that it will go sub -5 in 2 days: Sub -5 AOs are pretty rare and have always been accompanied and/or immediately followed by intense cold and/or wintry in parts and often much of the SE. Here are the ones during DJF since 1950: 1. 2/10-11/2021: major ZR GSO 2/12-13 2. 12/18/2010: significant to big snow one week later much of inland SE and light on coast 3. 2/6-7/2010, 2/14/2010: two winter storms (2/5, 2/12-13) affecting most of SE between them including some on coast 2/12-13 4. 1/2-6/2010: light snow N GA/very cold SE 5. 12/20-25/2009: winter storm mainly NC 12/18-19 6. 1/18-20/1985: 1-2 mainly light snows much of inland SE 1/17-20 followed by historic cold 7. 2/5-6/1978: several mainly light snows SE 2/2-9 including some on coast 2/8-9; very cold 8. 1/11-17/1977: snow events almost all of SE during and soon after including Miami and parts of Bahamas 1/19; very cold 9. 12/28-29/1976: several wintry events then into first few days of Jan inland SE; cold 10. 2/13-16/1969: major winter storm 2/15-17 Charlotte to GSP/Asheville; wintry precip most other areas within 2/14-17 including light on coast 11. 1/28/1966: several wintry events 1/25-30 including on coast 1/27 and 1-2 majors much of NC; extreme cold 1/29-31 12. 1/21/1963: extreme cold the week following; several light wintry events inland

The models remain unanimous with a low of sub -5 AO on/near Feb 15th. Below is the latest GEFS. Today (2/13) it was at -3.7, which is actually lower than the -3.25 this chart shows. That gives me extra confidence that it will go sub -5 in 2 days: Sub -5 AOs are pretty rare and have always been accompanied and/or immediately followed by intense cold and/or wintry in parts and often much of the SE. Here are the ones during DJF since 1950: 1. 2/10-11/2021: major ZR GSO 2/12-13 https://climate.ncsu.edu/blog/2021/02/rapid-reaction-back-to-back-ice-storms-pound-the-northern-piedmont/#:~:text=February 12-13 Storm&text=Reports aggregated by the National,weakened ground%2C caused numerous outages. 2. 12/18/2010: significant to big snow one week later much of inland SE and light on coast 3. 2/6-7/2010, 2/14/2010: two winter storms (2/5, 2/12-13) affecting most of SE between them including some on coast 2/12-13 4. 1/2-6/2010: light snow N GA/very cold SE 5. 12/20-25/2009: winter storm mainly NC 12/18-19 6. 1/18-20/1985: 1-2 mainly light snows much of inland SE 1/17-20 followed by historic cold 7. 2/5-6/1978: several mainly light snows SE 2/2-9 including some on coast 2/8-9; very cold 8. 1/11-17/1977: snow events almost all of SE during and soon after including Miami and parts of Bahamas 1/19; very cold 9. 12/28-29/1976: several wintry events then into first few days of Jan inland SE; cold 10. 2/13-16/1969: major winter storm 2/15-17 Charlotte to GSP/Asheville; wintry precip most other areas within 2/14-17 including light on coast 11. 1/28/1966: several wintry events 1/25-30 including on coast 1/27 and 1-2 majors much of NC; extreme cold 1/29-31 12. 1/21/1963: extreme cold the week following; several light wintry events inland

12Z Euro is much better with much further SE track and major winter storm at least NC

12Z CMC looks like it may have two waves. First wave gives NC a mixed bag of SN/IP/ZR.

But almost no snow most of NC fwiw due to it not allowing deep enough cold air to get in there first/too fast with the low. There’s good bit of ZR:

12Z Icon almost all snow for precip type in ATL area with 3-4” of snow from ~0.5” qpf. Would mean ATL area total snow to date of mainly 6-8” from 2-3 measurable snows and biggest snow winter since the similar 2010-1! Before that, one has to go back to 1992-3 for the great March SOTC on northside of ATL (including Sandy Springs/Dunwoody) for about that much snow in a season although less fell in the city south and more fell in Marietta/Cobb. Also, this would mean two major snows (3.5”+) this winter city northward. Last time that happened northside of ATL probably at least back to 1959-60 thanks to March! 1894-5 had two major snows all of ATL area thanks to the great frigid Feb of 1895.

0Z EPS has finally resumed. It does have more snow (10:1) in NC, N SC, and N GA than recent runs:

1. 0Z EPS appears to look better than 12Z although it looks like it is stuck on hour 168 at WB/Pivotal. 2. 18Z Mogreps (UK ensemble) looks pretty good with the offshore track of the low. What a big contrast of that with the 0Z UKMET/Euro ops! Edit: 3. 0Z Mogreps doesn’t look as good as 18Z with mean low track not as far offshore and thus not as cold over the SE.

0Z UKMET is coming in well inland unfortunately for SE snow lovers.

0Z Euro far inland track that can’t take full advantage of the Barney cold. Will there be a 2nd wave? No. Not a good run for SE snow/sleetlovers. But something for the ZR lovers in NW NC. Is this a viable solution? Of course it is, especially in a La Niña. But the Euro will very likely have big changes between runs for next few days as this threat is still 6-7 days out and we have an atypical for La Niña mid Feb very strong -AO/strong +PNA combo on the way along with a 1050s Arctic high set to plunge into the Plains 2/16-18 accompanied by -30s 850s and coldest temps likely going <0 into St. Louis.

0Z Euro Barney going crazy! Some of this is as cold as 53 BN with most of this pink area colder than 40 BN!! Matches near gasoline!

When I see the model consensus giving St. Louis a good shot at getting <0F for lows and barely above +10 for highs and the airmass has a strong +PNA to steer the bulk of the airmass down quite far but at the same time running into a moist WSW H5 flow (split flow), that combo is usually a good benchmark for good wintry mischief potential in the SE soon afterward.

So, 1st 3 major 0Z runs (Icon, GFS, CMC) all have a low to mid 1050s high plunging down Feb 16th-18th bringing down absolutely frigid mid -30s 850s into ND/MN (nearly as cold as the plunge of Jan 19-20) thanks to the tale end of a -5 AO steered by a strong +PNA during moderate MJO 8. This is a very rare setup in mid Feb, especially in La Niña. We should be very thankful for having this opportunity.

Nice hit in much of SC to SE NC:

2nd wave:

Barney’s in charge in the Plains so far on 0Z GFS thanks to a big 1050 mb high plunging down: colder than recent runs

Could we be looking at Brick Storm #2? Wx Channel already renamed 1/21-2 storm as Brick #1. You’re world famous now!

No Euro 12Z yet, but new weeklies (0Z based) just came out: This remains the week with the best opportunity for a significant SE wintry event, Feb 17-23: H5: 2m: qpf:

The last two 12 hourly UK ens runs have trended toward more cold air getting into SE from the Plains Arctic high along with the surface low’s mean track being further SE. Two runs ago, the mean low was tracking inland into N FL vs the current run’s 100 miles offshore the SE coast: https://www.pivotalweather.com/model.php?m=mogrepsgens&p=sfcmslp-meanmem&rh=2025021112&fh=198&r=us_se&dpdt=&mc=

All 5 periods of a sub -5 AO in Feb back to 1950 had wintry precip on or near those dates in RDU and/or GSO: 2021, 2010 (two periods), 1978, and 1969 fwiw. 12Z Euro still not started which means it’s at least 35-40 minutes late getting started.