Severe WX February 8th - 12th deep south severe threat.

[UncleJuJu98]

Here's a screen grab at around 5 oclock Wednesday off the WRF EHI of 1-2 from Mississippi to Alabama will be adequate. Heck the WRF even shows scattered supercells around Mississippi and Alabama.

All eyes should be kept on the trends for uptick, potential exists for a robust event wether it's a outflow boundary that drifts southeast from the line of storms along the boundary of the low pressure system or just a front boundary or something. Or maybe the low pressure drops 4mb sooner and faster and upticks shear in the upper levels. Just a lot of little things that could uptick this event. Seems like it teeters on the edge of bust or boom.

 

[JBishopwx]

.THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE LOWER
MISSISSIPPI VALLEY/ARKLAMISS...

...SUMMARY...
Severe thunderstorms are possible Wednesday and Wednesday night
across the Lower Mississippi Valley. This includes the potential for
damaging winds, a few tornadoes, and possibly some hail.

...Lower Mississippi Valley/ArkLaMiss and Tennessee Valley...
A shortwave trough and an increasingly strong polar jet will spread
northeastward on Wednesday from the south-central Plains/Ozarks
toward the Midwest and interface with an increasingly moist air mass
across the Lower Mississippi Valley/Tennessee Valley.

Early day cloud cover and scattered thunderstorms will potentially
be semi-persistent factors near/ahead of the cold front on
Wednesday. However, the pre-convective warm sector will
progressively moisten and cloud breaks should allow for modest
diurnal destabilization across Louisiana into Mississippi and
southern/eastern Arkansas. Some semi-discrete storms/supercells will
be possible, but the modest prevalent scenario of convection may be
quasi-linear bands with some embedded bows near the effective front.
Damaging winds should be the most likely hazard along with the
potential for a few tornadoes. The severe risk should develop toward
eastern portions of Mississippi/Louisiana by Wednesday evening, and
possibly reach western Alabama and/or western Tennessee later
Wednesday night.

...Lower Ohio Valley/Midwest...
The steady northeastward ejection of the shortwave trough and
related deepening phase (potentially reaching -1 mb/hr) of the
northeastward-advancing surface cyclone from the Ozarks to the
Midwest could influence a strongly forced low-topped convective line
across the region Wednesday night. Concern exists for the potential
of convectively enhanced wind gusts, possibly with little or no
lightning flashes, even in the presence of minimal instability with
northward extent. Given a pronounced nocturnal strengthening of
deep-layer winds (highlighted by 100+ kt mid-level jet), along with
steepening lapse rates atop residual but eroding boundary layer
stability, at least low wind-related severe probabilities appear
warranted even with thermodynamic uncertainties/limitations.

 

[UncleJuJu98]

I'm torn at the middle on the storm mode.

 

[UncleJuJu98]

Also where's @KevinH at? Usually he likes severe weather discussions.

You'll get your fill by the time the month is over ensembles support a few events of relatively significant troughing for the southeast it seems.

 

[UncleJuJu98]

Seems like timing may not be a issue for adequate mositure in fact late night arrival with higher shear and around 800-1400sbcape is decent for a squall line spin up or kinked line. Pretty volatile environment around midnight in missippi around the state line of Alabama.

 

[UncleJuJu98]

This is the WRF forecasted updraft swaths. Pretty good indication of a broken squall line with a lot of spinning in individual cells lol . I trust the WRF at this range until the short range hrrr.

 

[JBishopwx]

No real changes at the 17:30 update, granted I haven't look at the text.

 

[JPWX]

One thing that caught my eye was "a greater tornado threat could persist from evening to early overnight"

 

[UncleJuJu98]

One thing that caught my eye was "a greater tornado threat could persist from evening to early overnight"
View attachment 17616

Shear really upticks when the sun falls from the nocturnal jet kicking in and the low pressure starting to rapidly drop it seems. Could be a lot of spinners in the line,

Unfortunately it seems the gist of it now is going to be nocturnal in Mississippi

Rap shows around that 800-1400 range I usually go with for a winter event and around 350 range of 1km and 3km SRH helicity. Not sure at the low level lapse rates but I'm pretty sure the low level instability was pretty good at around 100-150

 

[UncleJuJu98]

00z hrrr run really has some strong updraft swaths near the triple point of the low with some pretty good parameters.

STP values reaching near 7 in southeast Arkansas

 

[UncleJuJu98]

I'd say a enhanced would be warranted near that area. I'd be weary if a boundary or something slides southeast from the rain mass/mcs.

The second squall line or mcs that Develops southeast of that good parameter space may cut off supply to the parameters so I'm not sure if the hrrr is catching on

 

[Timhsv]

Seems as the 08Z NAM run of CIPS has picked up a little more.

 

[JPWX]

I'll be surprised if there's not at least a small Enhanced Risk for parts of Louisiana into MS tomorrow.

 

[UncleJuJu98]

Seems as the 08Z NAM run of CIPS has picked up a little more.

That southeast corner of Arkansas is incredibly intriguing, potential there for a strong tornado is pretty high I would say. WRF and hrrr updrafts swaths

 

[Timhsv]

I'll be surprised if there's not at least a small Enhanced Risk for parts of Louisiana into MS tomorrow.

I'm in some agreement with you. If you take some of the numbers of the 08Z NAM alone, there's almost on 1 sounding along the Mississippi River north of Vickburg almost 2100 J/kg of CAPE and 0-1km at nearly 500 m2/s2. and Critical Angle at 63, with an increasing 850 jet from 60-70knts. I may be wrong, but I do see a possible upgrade near AR/LA/MS area.

 

[UncleJuJu98]

@Timhsv @JPWX for what it's worth this is the tornadocast

 

[Timhsv]

@Timhsv @JPWX for what it's worth this is the tornadocast

Yes sir. Interesting.

 

[JBishopwx]

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TX
ACROSS THE LOWER MS VALLEY...

...SUMMARY...
Severe thunderstorms are possible today and tonight from east Texas
across the Lower Mississippi Valley. This includes the potential for
damaging winds, a few tornadoes, and possibly some hail.

...Synopsis...
Upper low currently moving into the southern High Plains is forecast
to continue eastward across the southern Plains today, becoming more
progressive and negatively tilted as it does. An associated surface
low is currently centered about 25 miles west of TYR in east TX,
along a slow-moving cold front.

This surface low is expected to deepen while gradually moving
northeastward this morning, before then accelerating northeastward
this afternoon and evening as the upper low also accelerates
eastward/northeastward. The cold front is also expected to quickly
move eastward in response, likely extending from the low over
northwest AR southward through southwest LA at 00Z. Additional
northeastward progress of the surface low is expected thereafter,
with the low likely centered over central IL by 12Z. At that tine,
the cold front will likely extend southward from the low through
middle TN and then more southwestward through southeastern LA.

...East TX through the Lower MS Valley...
Widespread warm-air advection showers and thunderstorms will likely
be ongoing from central TX into eastern OK/far western AR this
morning, along and behind the cold front expected to extend from
northeast TX back southwestward into central TX. Limited buoyancy
should temper any severe potential with this activity.

Low-level moisture advection is expected to persist across the warm
sector, likely resulting in a broad area of mid 60s dewpoints ahead
of the front by early afternoon. Pre-frontal convection will likely
increase during the late afternoon/early evening across LA as ascent
spreads across the region. Buoyancy will be tempered by widespread
cloud cover and limited diurnal heating. In contrast, moderate
deep-layer vertical shear will be in place, supported by a
strengthening low-level jet, and the potential exists for organized
storms capable of damaging wind gusts and tornadoes. However, a
slightly elevated and more multicellular mode is currently
anticipated, with storm interactions potentially limiting updraft
organization.

Additional thunderstorm development is expected along the front,
with the moderate vertical shear contributing bowing line segments
capable of damaging wind gusts, and perhaps a line-embedded
tornadoes. Greatest chance for tornadoes within the line appears to
be from north-central LA eastward into central MS, where slightly
higher buoyancy could overlap with strong low-level jet in the
presence of surface-based storms.

...Arklatex into the Lower OH Valley...
The deepening surface low is forecast to track northeastward from
the Arklatex across central AR and southeast MO into central IL.
Ascent attendant to this low will augment the already strong forcing
near the upper low and associated jet streak, contributing to
thunderstorms just ahead of the low as it progresses northeastward.
Bowing line segments capable of damaging wind gusts and maybe a
line-embedded tornado or two are possible across southern AR this
evening. Despite limited buoyancy, the strong forcing for ascent may
contribute to additional damaging wind gusts overnight across
southwest MO and into southern IL.

 

[Argus]

Is this system going to cause storms over North Georgia anytime this week?

 

[UncleJuJu98]

Is this system going to cause storms over North Georgia anytime this week?

Not any severe storms, that'll be regulated to extreme south Georgia I think, probably have some rain maybe a rumble or thunder or two in north georgia