Wintry February 19-21, 2020 Winter Storm

[BackThePack]

great great post. so many comments under my facebook updates saying mets are saying its warm so stuff wont stick.

IDK why but ground temps are way way overexaggerated as a major impact. Sure it'll take a bit longer to stick and sure we will lose an inch to melt but its not like the snow is falling on 90 degree pavement lol

Soil temps are too warm for snow to accum is the most debunked myth of all time. Rates overcome ground temps 99.9999999999%

 

[FallsLake]

One big question for this event is the surface temps. The 12z HRW-WRF-NSSL would be wonderful for folks in central NC:

 

[Myfrotho704_]

fwiw, the NAM does show weak instability during the snow/sleet with elevated CAPE (even weak SBcape, and elevated K-index temps

 

[packfan98]

Parts of the GFS are rolling out. It's much drier than 6z for the NW regions.

 

[ryan1234]

One big question for this event is the surface temps. The 12z HRW-WRF-NSSL would be wonderful for folks in central NC:

View attachment 35614

That's a great look! Even here in the Southern Piedmont, if only that came to fruition. If it did, the Charlotte area could cash in. Sometimes sitting on that transistion line can do wonders. I.e. Feb 2004.

 

[WxBlue]

In my opinion, the storm is moving through at such a pace that I think it'll be hard to pull off 10"+ somewhere even under an intense band. That's a strong jet that it's riding on so it's gonna scream through the region rather quickly.

 

[SimeonNC]

fwiw, the NAM does show weak instability during the snow/sleet with elevated CAPE (even weak SBcape, and elevated K-index temps View attachment 35615View attachment 35616

So that supports Roberts assertion of possible thundersnow/sleet, I wonder if that would affect accumulations?

 

[NickyBGuarantee]

Wow RAP 15z looks to have increased precip significantly by 18z Thursday for East Tennessee and moving into NC ... could be a fun run


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[Myfrotho704_]

So that supports Roberts assertion of possible thundersnow/sleet, I wonder if that would affect accumulations?

Maybe more Convective nature to banding

 

[Myfrotho704_]

Wow RAP 15z looks to have increased precip significantly by 18z Thursday for East Tennessee and moving into NC ... could be a fun run


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Still meh, sfc temps to warm, it’s BL issues may be showin like the hrrr, or there’s a very tiny chance it’s onto something

 

[iGRXY]

Still meh, sfc temps to warm, it’s BL issues may be showin like the hrrr, or there’s a very tiny chance it’s onto something

The soundings actaully look good except for the surface. It's right on the 32 degree line in the northern upstate which would be snow.

 

[accu35]

Wow!! Much better run for north Al/Tn

 

[accu35]

 

[NCCWOP9077]

12z HREF valid 3pm Thursday afternoon, just to show how far north the warm nose gets before it begins to move SE

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[NCCWOP9077]

Total snow accumulation (PMM) for the entire model run, jackpot (6-8) is NE NC with a stripe of 4-6 inches in the darker blue shading

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[crecre9]

NWS Huntsville remains very unimpressed for the N AL area.

"The precipitation
may briefly begin as sleet, especially for northwest AL and our
southern TN counties, where low-level wet bulb profiles are a bit
more favorable. As the surface trough to our south advances eastward
across the northern Gulf during the day, forecast soundings suggest
that reinvigoration of cold air advection in the low-levels will
provide an increasingly favorable environment for a rain-snow mixture
(or perhaps all snow) during the 12-18Z timeframe, mainly for
northwest AL/southern TN."

 

[Downeastnc]

I think( hope) the models mix to much and keep the surface too warm to long, there is not a big warm nose aloft to overcome like we often have to deal with, hopefully the NAM is not quite as amped and we see that go back away….the warm is at the surface and decent rates will get the snow to the surface quickly IMO and once it goes snow it stays snow. There could/should be a couple of decent bands form one that runs west to east that forms over the northern coastal plains and drifts south and another more SW to NE that forms over interior central NC and drifts SE as the low slides out.....

Personally for MBY I think worst case for the PGV area is 3-5" of snow and .5-1" of sleet if we mix a lot.....best case is probably around 12-14" of snow. Just the fact that things like 6-12" in places is even on the table is awesome IMO and tomorrow should be fun....

 

[NCHighCountryWX]

Soil temps are too warm for snow to accum is the most debunked myth of all time. Rates overcome ground temps 99.9999999999%

happened last week In Indianapolis

 

[Pup12]

NWS Huntsville remains very unimpressed for the N AL


Must be ignoring the NAM, but it’s been solid so far this season ??‍

 

[accu35]

NWS Huntsville remains very unimpressed for the N AL area.

"The precipitation
may briefly begin as sleet, especially for northwest AL and our
southern TN counties, where low-level wet bulb profiles are a bit
more favorable. As the surface trough to our south advances eastward
across the northern Gulf during the day, forecast soundings suggest
that reinvigoration of cold air advection in the low-levels will
provide an increasingly favorable environment for a rain-snow mixture
(or perhaps all snow) during the 12-18Z timeframe, mainly for
northwest AL/southern TN."

What's so bad about there forecast? it's not over doing it and we all know there are surprises in these setups, plus 12z 18z time frame with possible all snow isn't bad. Plus FWIW the gefs came in colder and more snow for areas of north Bama.