Possible significant severe wx outbreak 11/23-24

[SouthernWx]

Not a time to panic, but evening model guidance continues to forecast atmospheric ingrediants that could create a significant severe weather outbreak in the Tuesday-Wednesday time frame next week (11/23-24). The most likely area to experience dangerous weather appears to be from east Texas across the Gulf States toward Alabama and Georgia....possibly as far north as the Tennessee and lower Ohio Valley.

Both the GFS and ECMWF prog a developing storm system to move out of the southern Rockies Monday and deepen rapidly as it moves across the Mississippi Valley toward the Great Lakes. With such a vigorous storm system, extremely strong wind fields (850 mb LLJ in excess of 50 kt; upper jet core of over 150 kt at 200 mb), and unseasonably warm weather forecast in advance of the approaching storm....it has the possibility of producing severe storms, serious flooding, and possibly tornadoes. A band of heavy wintery precipitation is also possible to the northwest of the storm track...across portions of the central Plains and upper Mississippi Valley/ western Great Lakes area.

There's no way to know this far in advance just how widespread the severe thunderstorms will become or exactly where tornadoes are most likely to occur, but in light of the fact we are approaching the Thanksgiving holiday, and many folks will be traveling early/ mid next week, decided it was prudent to give everyone an advance heads up on this potentially dangerous weather event.

PW

[yoda]

Yes. This looks to be a strong Appalachain runner, or the low may go a bit further west...

[Guest]

Yep i agree here this looks to be a big event. My main areas for concern would be from central eastern TN/KY down to Northern AL, GA, MS and then the Carolinas and Virginia for the biggest severe wx threats.

On the colder side of things the areas that stand the best chance of accumulating snows ( the first for most btw) would be from N.MO, IA, WI, N.IL, N.IN and MI with the exception perhaps of SE Michigan from Near Detroit on south.
Only problem will be with areas right on or close to the lake such as Chicago which may have a harder time switching over from rain to snow because of the warmer lake waters. Best hope is to have the wind quickly as possible go to the nnw or nw. Which will happen. Just a matter of when.

This as well could bring the first big lake effect event as well behind the system in northern and W.MI, N.IN, ne.OH, W.PA, W.NY.

[Stormsfury]

I noticed this also with model consensus starting to come to a head in the past couple of days ... I didn't want to get into a lot of details, but with current model progs, this could be quite a healthy outbreak ...

SF

[PurdueWx80]

The support is about is strong as it gets (any time of the year) as far as the wind/shear profile goes, particularly in the TN Valley. While the surface low/triple point will likely move across the middle MS Valley and Lakes on Tuesday/Wednesday, the powerful midlevel vort and associated shortwave trough in the south will induce southwesterly midlevel flow over a 50-60 kt low-level jet. The whole Midwest, TN Valley and parts of the south will be under the influence of coupled upper level jets, so the divergence will be there for widespread and deep convection. Great call on the chances for severe weather, Southern, this may be an event to remember if the models predictions come to fruition. Right now, the main event looks to happen on Tuesday, and as long as the air mass over the Gulf equilibrates and the flow sends that warm, moist air northward, this could be a big time tornadic outbreak. Activity further to the north may be retarded by convection over the South, especially if a squall line can consolidate early on. I think the models are grossly underdoing temps all across the east for Monday and especially Tuesday. I wouldn't be surprised to see 70's as far north as the Ohio Valley and perhaps even in the lower Lakes, especially if skies can clear out for a few hours in the afternoon. 80's are probalby likely south of the Mason-Dixon line. The snow areas I outlined earlier this week still look pretty good in my mind (NM/TX to KS/MO to WI/MI.) Thanksgiving looks brisk and very cold all the way to the Gulf Coast and Eastern Seaboard.

[Fred Gossage]

There's one little thing that stuck out to me on the 12Z GFS run.... At 700-mb...there seems to be a little shortwave moving northeastward across Tennessee with the surface warm front. If you look at the 700 RH profiles to the southwest of it....there is a pool of mid-level dry air there. That would tend to promote some subsidence, especially early on in the day, which would, in turn, allow for breaks in cloud cover and the sun to shine through. That may, in turn, enhance instability even further.

[MGC]

Just reading the forcast discussions from Jackson Ms and New Orleans. Jackson is really concerned about a potential tornadic outbreak. Looks like all of MS, AL, GA will be in warm sector and the potential for isolated supercells are a real concern. November is tornado season in the gulf states. I still have vivid memories of the Nov 21 1992 tornado that passed just east of my home in Brandon MS. It was an F-4 and it killed 10 people.......MGC

[breeze]

Thanks for the "heads-up", folks. The local
Nashville mets and the NWS out of Nashville
are simply saying "thunderstorms" for us in
southern mid-TN for Tuesday into Wednesday.
They may even change their tune, closer to
Tuesday!

[PurdueWx80]

Thanks for the "heads-up", folks. The local
Nashville mets and the NWS out of Nashville
are simply saying "thunderstorms" for us in
southern mid-TN for Tuesday into Wednesday.
They may even change their tune, closer to
Tuesday!

They'll be talking about it once the exact location of the highest risks are honed in...don't expect that to happen until Monday or Tuesday. A lot of the ingredients (mostly surface wind and instability) won't be certain until the day of.

[JuliannaMKH]

Just dittoing thanks for the heads up.
Huntsville, AL discussion is saying possible severe thunderstorms and high winds Tues-Weds but it sounds like they're kinda waiting to see what happens before they solidify any forecasts.

Mmmm. Holiday Severe Storms. My favorite. (/sarcasm)