• Hello, please take a minute to check out our awesome content, contributed by the wonderful members of our community. We hope you'll add your own thoughts and opinions by making a free account!

Wintry February 19-21, 2020 Winter Storm

GaWx

Supporter
Member
Joined
Jan 5, 2017
Messages
6,809
Reaction score
14,032
Location
SAV, GA
You are likely correct. Been a minute😁
I didn't experience it, but I sure followed it! There was a 1007 mb GOM low, phase 7 MJO, strong +PNA, -EPO, -NAO, and neutral AO. At KATL, 4.6" of 10:1 ratio. SN from Montgomery to NC.

Yes, the setup looks to me like it could produce a long duration SN of 12+ hours.
 

Jessy89

Member
Joined
Oct 9, 2018
Messages
1,458
Reaction score
1,198
Location
Liberty sc
Is this good or? Again, I’m sorry if this isn’t appropriate, I’m just trying to learn


Sent from my iPhone using Tapatalk
Well it doesn’t go out far enough to know if it’s good or bad. It shows the front draped out across the Carolinas. We got to see where that front stalls


Sent from my iPhone using Tapatalk
 

Brick Tamland

Member
Joined
Jan 5, 2017
Messages
5,840
Reaction score
4,619
Location
Wake Forest, NC
And just like that the GFS says game on. This is why folks should not get and worry about so-called trends inside a 24 hour period. Anytime we have a threat of a winter storm it is a fluid situation, and the models are going to change and go back and forth this far out. They are still trying to figure things out. It's like a basketball game, sometimes it's a close one and the game goes back and forth. We were starting to lose on the models earlier today, but right now we're winning again.

And for folks in NC, you have to really like where the bullseye is on the GFS run when you consider it usually shifts NW the closer we get to the storm getting here.
 

Dawgdaze22

Member
Joined
Feb 7, 2020
Messages
61
Reaction score
59
Location
Atlanta
While it’ll probably trend north some, I still like SC (including Columbia SC in this setup, gonna be hard to get this thing as far north as Central VA/DC like how are other ones have trended to due to the strength of that trough in SE Canada
How is this setup for north Georgia?


Sent from my iPhone using Tapatalk
 

Webberweather53

Meteorologist
Joined
Jan 5, 2017
Messages
8,634
Reaction score
22,256
Location
Charlotte, NC
Here's my 2 cents on what I'm seeing atm w/ this potential overrunning event next week.

The difference between a storm and no storm late next week imo relies almost entirely on the orientation of the longwave trough centered over the Lakes - midwest - & into the south-central Rockies & Great Basin, not on whether we get the s/w out of the SW US to emerge from the Rockies, there's actually more than one way we can produce the solution we want here.

The reason we've lost the storm on the Euro is because this longwave trough has become increasingly positively tilted (from SW-NE to basically W-E) and the flow underneath it over the SE US has thus veered from the WSW in earlier runs to W-WNW in later suites. The reason for that has everything to do with the wave over the southwestern US lagging further behind and failing to pump the heights over the SE US and create W-WSWly mid level flow. Even if this wave continues to trend unfavorably, the other way we can get back to the snowier solutions on earlier runs and pump the heights in the SE US is if this northern stream wave over WI, MI, IA, & MN slows down and/or digs further west (say towards western IA, Nebraska, or the Dakotas instead). I think these desired changes are very doable inside day 5-6 and I wouldn't be shocked if our storm "came back" on the Euro/EPS in later runs.

trend-ecmwf_full-2020021412-f138.500hv.conus.gif


When you compare the Euro & GFS 500mb vort around day 5, it's easy to see why one has a storm while the other doesn't.

Euro is much faster (& thus further SE) with the northern stream wave whereas the GFS slows it down & is less progressive for once (surprisingly). The GFS thus allows the heights to rise more over the SE US & therefore pushes the eventual sheared, overrunning wave further NW, bringing snow to parts of the deep south.

Even if you took both of these modeled patterns at face value, I'd still expect precipitation associated w/ said wave to be a bit stronger & further north than modeled due to aforementioned model biases wrt low-mid level warm advection. Stronger warm advection not only = stronger warm noses as we see time & time again, but if it's one of the primary forcing mechanisms (along w/ differential CVA) that's driving precipitation as it often is during overrunning events, this also means said precipitation will be more expansive in coverage and intense than forecast. Hence, I'm pretty skeptical of the suppressed solutions atm being offered by the ECMWF.

In any case, given the aforementioned discussion, it should be pretty obvious what trends we need to see the next few days to give much of the board a nice overrunning event:

Our longwave trough needs to be less positively tilted & the adjacent SE US ridge has to be stronger. Therefore, the evolution of both the northern & southern stream waves will be key here.



500hv.conus (1).png

500hv.conus.png
 
Top