Latest SPC Outlook

It looks like Central and Southern Mississippi as well as Southern Arkansas and Northern Louisiana could be dealing with organized severe thunderstorms, including a fairly substantial tornado threat tomorrow. 

Around here it looks more like a basic risk of damaging thunderstorm winds within the squall line Tuesday evening/night. Roughly from 6 PM to Midnight is when the line should move through. The risk for severe thunderstorms is more marginal as you get up into the Tennessee counties compared to North Alabama. 

 SPC AC 030550

   Day 2 Convective Outlook  

   NWS Storm Prediction Center Norman OK

   1150 PM CST Sun Mar 02 2025

   Valid 041200Z - 051200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS TUESDAY INTO

   TUESDAY EVENING ACROSS SOUTHERN ARKANSAS...MUCH OF NORTHERN AND

   CENTRAL LOUISIANA AND CENTRAL/SOUTHERN MISSISSIPPI...

   ...SUMMARY...

   One or two organized lines or clusters of thunderstorms, and perhaps

   a few supercells, will pose a risk for damaging wind gusts, a few

   tornadoes and hail, primarily across parts of the lower Mississippi

   Valley into the Southeast, Tuesday through Tuesday night.

   ...Discussion...

   Model output remains varied concerning sub-synoptic developments

   into and through this period.  However, better consensus is evident

   among the various model ensemble output concerning the large-scale

   pattern evolution across the eastern Pacific into North America. 

   Within this regime, a significant upper trough, now inland of the

   Pacific coast, is forecast to progress east of the Great Plains

   through Mississippi Valley Tuesday through Tuesday night,

   accompanied by continuing strong cyclogenesis.  

   Models generally indicate that the center of the evolving broad and

   deep surface cyclone will migrate from western Kansas through

   northern Illinois during this period.  In the wake of the cyclone, a

   substantive cold front is forecast to surge southeastward across the

   southern Great Plains into northwestern Gulf coast and lower

   Mississippi Valley by 12Z Wednesday.  This may be preceded by a more

   modest Pacific cold front across the southern Great Plains at the

   outset of the period, and potentially cool/dry air across/east of

   the lower Mississippi Valley, associated with a surface ridge

   shifting off the Atlantic Seaboard, in the wake of de-amplifying

   large-scale mid/upper troughing.

   A southerly return flow off a modifying boundary-layer over the

   western Gulf Basin is likely to be ongoing early Tuesday across

   eastern Texas toward the lower Missouri Valley, before shifting

   eastward across and east of the lower Mississippi Valley.  In

   response to the evolution and progression of the cyclone, models

   suggest that better low-level moisture return from the Gulf will

   probably become cut off across the eastern Gulf Coast region by late

   Tuesday night.

   Across and northeast of a low-level baroclinic zone, initially

   extending across the Ark-La-Tex vicinity southeastward through

   southern portions of the lower Mississippi Valley, the Gulf moisture

   return will initially become elevated above a residual cool/stable

   surface-based layer.  However, the NAM and Rapid Refresh output

   still suggest that this boundary will become more diffuse while

   developing eastward through the day.

   Regardless, most model output remains suggestive that elevated

   and/or closer to surface-based destabilization, and large-scale

   ascent associated with the cyclone, will become sufficient to

   support extensive convective development across the interior U.S.

   Tuesday through Tuesday night, and a fairly broad area with at least

   a conditional risk for severe storms.

   ...Lower Mississippi Valley into Southeast...

   The remnant, though becoming increasingly diffuse, baroclinic zone

   across the lower Mississippi Valley, might become the primary

   initial focus for intense thunderstorm development during this

   period.  As the environment destabilizes more rapidly to the

   southwest of this boundary, and low-level warm advection along it

   contributes to large-scale ascent accompanying a short wave

   perturbation overspreading the lower Mississippi Valley, conditions

   may become conducive to the evolution of an organizing storm

   cluster. This may be preceded by a couple of discrete supercells.

   Given the strength of the deep-layer mean wind fields, which may

   include a belt of south-southwesterly flow in the 850-500 mb layer

   on the order of 60-100 kt overspreading Louisiana and Mississippi

   during the day, there appears at least conditional potential for

   supercells capable of producing strong tornadoes.  With the

   strongest wind fields generally forecast in the inflow layer of the

   convective development, the extent of the damaging wind potential

   remains more unclear, particularly with any evolving cluster

   developing along/above a maturing cold pool

   Much will also depend on the extent to which near-surface

   thermodynamic profiles are able to destabilize in advance of the

   large-scale forcing.  Both the latest Rapid Refresh and NAM forecast

   soundings suggest this may be an issue, and potential mitigating

   factor with regard to the severe wind and tornado potential,

   particularly overnight east of the lower Mississippi Valley into the

   eastern Gulf Coast states.

   ..Kerr.. 03/03/2025