1/10/08 FCST: LA,MS,AL,FL,GA,TN,KY

[Justin E. Reed]

A new low presssure system is forecasted to move into the Plains early Thursday morning, and intensifying throughout the day. A jet streak of almost 100kts is going to move into the trough area and rapidly move northeast with the system. Strong southerly and southeasterly winds will bring a heavy amount of GOMEX moisture northward into the Gulf Coast, MS/TN Valleys, with temperatures anywhere from 65-75 degrees, with dewpoints in the 60's up to KBNA, with 50 dewpoints up to the Ohio River. Shear will definetly not be an issue in developing, as winds will continue to intensify at the surface all day. It should be a mainly partly cloudy sky, allowing for a good amount of heating, increasing an already somewhat unstable airmass. Supercells are likely, with a squall line developing in the evening, spreading further into GA, FL, and the Carolinas. Definetly keep abreast to the situation for tomorrow! The biggest threat is for central and northern Alabama, eastern Mississippi, northwestern Georgia, and extreme southern Middle Tennessee.

 

[Brett Adair]

Instability values in Central Alabama are nearing 1500J/kg on the GFS. The ECMWF has been showing a deeper system for days. The NAM continues to trend in this general direction. The 100 knot 'barb of death' was shown on last nights run so this looks to be pretty serious with parameters coming together especially since thermodynamic fields look to be underestimated on the NAM. Something to continue to watch, but definitely a chase day is in the works not to mention the possibility of a risk upgrade.

 

[Angie Norris]

Classic severe weather setup for the southeast tomorrow. Warm front looks to extend as far north as Ohio with temperatures into the 60s, with 70s into central MS/AL. Moisture will be in place with dewpoint into the 50s as far north as KY and mid 60s in MS/AL and southern GA. Shear is more than adequate. Upper divergence will definitely enhance lift as the huge 500mb trough digs into the MS/AL area. The NAM doesn't depict CAPE as being that high, only about 500-1000J/kg, but this time of year, in that area of the country, that's more than enough to wreck some serious havoc. CAPE looks to spike through the central KY/TN area back into MS and AL at 0Z. The only negative that I can see is the ongoing precip depicted by the NAM and GFS...that would pretty well kill any surface heating.

Would expect the best chances of severe in the central MS/AL area, but anywhere from KY south could be fair game tomorrow. Dynamics are the best in the MS/AL area, with the best heating, moisture and shear. Any descrete storms that form should have no problems rotating, but they will also be the 45-50mph speed racers. Looks like the associated cold front will blast through the region after 6Z on Friday, with an associated squall line.

 

[Justin E. Reed]

Damn, this happening on a day I gotta work, oh well, at least I'm a meteorologist, well, for the Navy so to speak, well, observer to be exact. I'll definetly be watching this closely, More than half my family is in Alabama, I can possibly see a March 1st, 07 type event happening, with probable upgrade to MOD risk tomorrow morning. Line of fire metros include: Birmingham, Montgomery, Huntsville, Chattanooga, Mobile-Pensacola, Gulfport-Biloxi, Jackson, and New Orleans. Possibly as far north as Nashville, Louisville, and Cincinnati. W/O a doubt, focal point will be a Meridian, MS to Birmingham line I believe.

 

[Justin E. Reed]

That was yesterday's sounding.

Oh, thanx, dang, I deleted my post.

 

[Brett Adair]

We will likely be headed out in the early morning to setup somewhere around Tuscaloosa where the CAPE axis looks to spike tomorrow afternoon. I do see the worst action occurring in the NWS-BMX CWA. Hopefully the SPC will upgrade this to a MDT risk on the new day one tonight because it certainly looks to warrant one at this point.

 

[Tony Laubach]

I am also chiming in as a fortunate series of circumstances will actually have me flying into Atlanta tomorrow morning. I am leaving at midnight Denver time tonight to land at 5:30 EST in Atlanta where I'll head out to Birmingham initially and adjust from there. The cost of all this will be less than a typical chase trip to Hays, KS from Denver and for me.

Certainly looks promising for severe weather which is amazing for early January. I'm thinking temps of 70 will be more likely as the warm front lifts north and lands the target area back into the warm sector. Clouds should clear enough to allow for the heating needed to realize the instability.

Storm motions, as usual with this type of system, will be racing and make for a wild ride. I think cells ahead of the line are possible and will make for the best play early before the cold front and squall line race through.

More on my blog as all this unfolds for me.

 

[Terry Tyler]

i am very impressed about tomorow...

it looks alot better in my part of the state then i could think of...very balanced in the atmosphere as far as the 30 HR nam was last night...

dew points in the low to mid 60s, 0-3KM cape from 80-120 j/kg and 0-1KM helicity from 250-300 with up to 1000MLCAPE and a wicked 85kt+ jet kicking in...

it looks pretty good to me...im just happy its probably going to start earlier in the day so i can see it...

if anything forms near here, im gonna go try and see whats up!

 

[Dave Gallaher]

I have to report to work in Huntsville at about 5pm, but I'll be out and watching for intercept possibilities in the area west of here up until then, and maybe later if the action gets good around here.

Welcome to Alabama, Tony--wear your overalls.

 

[Angie Norris]

Not a lot of difference in the 0Z runs. Both NAM and GFS have precip breaking out by 18Z, with the cold front moving through with a wicked squall line in the overnight time frame. The main problem continues to be just how much will the ongoing precip limit instability.
I'm looking at the area from Chattanooga, TN to Tuscaloosa, AL to Tupelo, MS to Shelbyville, TN as the primary area of interest due to a nice CAPE spike and good divergence at 500mb. If I could chase, I'd be headed to Huntsville, AL as a starting point.
Good luck to everybody venturing out...storms will be speed racers in the trees and hills...

 

[Justin E. Reed]

Well, the new Day 1 Outlook is out, 10% chance of tornadoes in AL and MS. They have stated this "FORECAST IS SUBJECT TO UPGRADE IN SUBSEQUENT OUTLOOKS ONCE STORM FOCI AND AREAS OF MOST FAVORABLE DIURNAL SFC HEATING BECOME BETTER DEFINED." So I am feeling good on a MOD outlook, probably coming out by lunchtime Eastern time. I am keeping a very close eye on condition in Birmingham and Nashville, since they are locations where I have family, and scattered throughout AL, anywho very good chance of a fair sized outbreak of tornadoes. Unfortunately, cloudiness covers Alabama, mainly between 030 and 065. Thunderstorms are currently in progress over AR, LA, and GA with the warm front. Can;t wait for 12Z Soundings.

 

[Justin E. Reed]

New soundings are out for the 12Z run. Jackson, MS, Shreveport and Lake Charles, Louisiana all have impressive soundings. Jackson,MS although is where the focal point for supercells is likely to initiate. The tornado threat has been back to a centered area around Tupelo and Columbus, MS as well. Thunderstorms continue to erupt in AR, TN, and AL, along and in the area near the warm front. Memphis has been hammered with good storms this morning and will continue for a few hours. Thundershowers are developing over New Orleans and Slidell at this time as well. A new tornado watch may be issued for MS, southeastern AR, and eastern LA by mid morning it appears, according to the SPC, and I agree highly, and its likely to be in a squall line formation, with more isolated supercells in Alabama with afternoon heating.

UPDATE: Speaking of a watch, right where I said, Most of MS from the TN line, down to baton Rouge, west to Opelousas,LA, and east to the NW suburbs of New Orleans. It expires at 4pm/1600 pm Central time.
Tornado Watch #16
http://www.spc.noaa.gov/products/watch/ww0016.html

 

[Karen Politte]

The stage appears set for a good ol' wintertime SErn US tornado outbreak. SPC upgraded to a MOD over parts of MS, AL and TN with their 1630Z Day 1 outlook, and given the ongoing line of intense storms all the way from LA's Gulf Coast to Nrn Tennessee, I would say that this is warranted as most areas east of this line will see severe weather in their vicinity as portions of the line pass.

That of course is not also taking into account the enhanced threat for tornadic supercells - which appears likely and with it a greater-than-average possibility for destructive tornadoes in parts of eastern MS, northwestern AL and southern TN. A tornado watch is already in effect for most of MS and portions of their neighbouring states to the south and north, but with cells already developing well ahead of the cold front in the warm, moist return-flow air of SErn MS, I expect another tornado watch to be issued shortly for these areas. As the upper system interacts with the true-CAPE air that has been injected into central MS (and further north eventually) by midday or mid-afternoon, everybody should be on the lookout for strong, severe storms, tornadoes and huge hail. Just another day in the jungles of MS and AL!

The 15z run of the RUC backs surface winds in response to the ever-deepening surface low (996mb by 0Z) very impressively across most parts of TN and parts of AL by 1800UTC. If this can happen, a significant tornado outbreak may be possible yet again with this multi-day trough.

Seeing as storms are currently ongoing, this FOREcast may be a little moot, but if I were to be chasing today (and not sheltering in my 'fraidy hole like a sensible citizen as the freight trains pass), I would target areas between Florence and Huntsville, AL for some significant severe and, if we can back the surface and have discrete cells fire ahead of the line, significant tornadoes.

Good luck to all who are trying to chase today - don't forget your machetes.

KL