burrel2

4 minutes ago, DopplerWx said:

the HP is sitting in the midwest, much different than here. hrrr does not have a warm bias that i have seen, has nailed MANY rain/snow lines over the past few winters.

Hrrr from this morning shows rain flipping to snow in Mississippi around 5am... Latest runs have that flip happening between 11pm and midnight. 

But more than that, from years of watching the Hrrr... it has a warm bias at the surface out past 10 or 12 hrs.

Hrrr has a warm bias. Check out it's 7am run today for the San Antonio area... Notice no hint of snow falling anywhere in that region.

Just now, CARDC79 said:

Aren't we at best looking at 6:1 versus 10:1 on the map?  Or maybe even 4:1 aka White Rain...

White rain is 0:1

Follow the RGEM in the 12 to 36hr range... it's usually right. IMO

Normally that's bad news for us, but in this case it looks slightly better for SC/piedmont NC. We'll see if it nails it this time...

I've been burned many times by surface layer warm air that doesn't evaporate as fast as I had hoped, but.... those other times often involved a thicker warm layer, and daytime snow in late february or march where solar insolation would eat in to accumulating snow even at 30 degree's.  We are just a a couple weeks away from the solstice right now.

I honestly would be ready to push my chips all in for a hammer job if all of the models weren't stuck on bottoming out the upstate at around 35/36. I just don't see how that will be the case if it's ripping it outside at 8am tomorrow morning like most models are showing. But if it is... we won't have any chance for accumulations. 

Rgem is adding on an inch or two of accumulations Saturday morning from the back side.... Hope that pans out.

Dang, check out the back side precip shield Saturday morning on the RGEM... similar to what the GFS is hinting at I suppose. 

FYI, I've found this RGEM product's rain/snow/mix line to be deadly accurate in past events...

http://collaboration.cmc.ec.gc.ca/cmc/cmdn/pcpn_type/pcpn_type_gem_reg.html

18z RGEM just showed up...

Just now, Rainforrest said:

Not according to gap. Lol

Won't be the first time they've busted badly.

I could see this one busting majorly for the upstate in a good way. If we get heavy rates tomorrow morning and quickly overcome the shallow warm air at the surface, we could be off to the races with an inch of liquid falling down as heavy sticking snow at 32/33,(plus the sun angle isn't bad at all like it is in feb/march).  In the perfect scenario I think north of 85 could get 5 or 6 inches of paste.

On the other hand, the shallow warm air at the surface could hold strong and we get our inch of liquid with nothing more than white rain pelting down and melting on contact all day.

Warm nose at 750mb could also set up a little farther north than models show and preclude us from any snow.

Odds are something goes wrong and we get mostly rain or non-sticking slop, but there is certainly a non-zero chance we get pasted with significant snow-storm.

Edit to add: The southern Mountains are going to get smoked. I think that's a lock now.  Highlands/cashiers/lake toxaway, towards caesar's head will get get 6 to 10 inches, IMO.

Hrrr is usually torching us 18h ours out, and it has the northen upstate flipping to snow by 7am Friday.. which is way ahead of schedule with most other modeling. Maybe the Hrrr and Rap are on to something.

A nice band of snow showing up on the Hi-res NAM around lunchtime Friday up the I-85 corridor in SC. If it plays out like this I think the upstate could get a quick inch or two of snow as the heaviest burst comes through.  Both the Hi-res NAM and RGEM are really slow to change over from rain to snow here, which I don't understand looking at the soundings. From what I see we should flip over to snow relatively quickly once rates pick up. We'll find out I guess.

2 minutes ago, snowlover91 said:

I wouldn't put too much stock in the RGEM surface temps. It has a known cold bias and in events like this the NAM usually does the best in the short range.

Huh? Rgem normally does very well with thermal profiles.

3 minutes ago, griteater said:

Agree Buddy, should see a little more storm with this run

I'm thinking it's about to spit out a blockbuster hit!

16 minutes ago, mackerel_sky said:

NAVGEM looks to have a deform band over us!!? How are temps that run?

The battle lines for these runs appear to be similar to the winter storm we had last January. IE: you want to be north of I-85

06z Navgem doubles down on the westernNC/SC crush job. Verbatim it's showing well over a foot of snow in the mountains/foothills.

Here is 7am Friday to 1pm Friday totals, and 7pm Friday to 1am Saturday totals... it's a lot of liquid!!!

Navgem is firmly in the ukmet/cmc/jma camp...

So we have UKmet/JMA/CMC that are amped with precip shield all the way back to western TN. This puts the warm nose/ mixing with rain line closer to the i-85 corridor. JMA is the coldest in that regard.

Then we have NAM/GFS with a more muted precip shield, but the warm nose/mixing in line is further south/east.

Euro falls somewhere in the middle of the two camps.

This doesn't take in to account the surface warm layer,(hopefully we can overcome that with decent rates.)

FWIW, the JMA is dropping over 30mm of liquid over my back yard for the event, with 850's never rising above -2C.   That's 1.18 inches of liquid!  

00z JMA... continues to be cold and amped...would be a massive snow storm for the 85 corridor.

Most of the ensemble members on the GFS are more bullsh with the westward extent of the precip shield compared to the OP. Maybe the JMA is on to something!

12 minutes ago, FLweather said:

Not all of that is frozen. Alot of that falls as rain. But to continue the Jma. H5 slightly negative. 

 

 

It's all frozen for Western NC/SC(mby). Raleigh to Charlotte would most likely have mixing issues with that track.

Liquid from 7am Friday to 7am Saturday

12z JMA is a big dog! This is the best look possible, IMO. I hope it's on to something. Hard to tell with the crummy maps, but it looks like this is drop 1"plus of liquid across my area with supportive temps for snow.