SPC Mar 7, 2024 1730 UTC Day 2 Convective Outlook

[NorthGeorgiaWX]

SPC 1730Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1130 AM CST Thu Mar 07 2024

Valid 081200Z - 091200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SOUTHEAST OK
AND EAST TX TO SOUTH AL...

...SUMMARY...
Scattered severe thunderstorms capable of producing tornadoes,
damaging winds, and large hail are expected from parts of east
Texas/Oklahoma across the lower Mississippi Valley and parts of the
central Gulf Coast States, on Friday afternoon into Friday night.

...Synopsis...
A positive-tilt upper trough will shift east from the Southwest to
the South-Central States with a pair of embedded shortwave impulses.
Fast mid-level southwesterlies, in excess of 80 kts at 500 mb, will
shift from south TX to the Ark-La-Miss by 12Z Saturday. A modest
surface cyclone should shift from north TX towards the TN Valley.

...South-Central to Southeast States...
Two potential mesoscale corridors of concern remain evident with a
probable bimodal distribution to the overall severe threat,
encompassed at this time with a relatively broad cat 2-SLGT risk. 

Clusters of convection will likely be ongoing at 12Z Friday across
parts of central/eastern OK/TX into the Ark-La-Miss. This activity
may continue to pose mainly a threat for isolated severe hail as it
moves east-northeast, given the presence of modestly steep mid-level
lapse rates and strong deep-layer shear. The southern bounds of this
convection should effectively suppress the northern extent of
appreciable surface-based destabilization into the Mid-South region.
In addition, the low-level warm theta-e advection regime will
persist through the diurnal heating cycle, yielding convection
persisting across MS into AL into the afternoon, further limiting
the northward advancement of the surface warm front. 

Afternoon to evening thunderstorm development should be focused
within two regimes. One may evolve in the Ark-La-Tex to Ark-La-Miss
vicinity where large-scale ascent is focused ahead of the surface
cyclone and attendant mid-level shortwave impulse. While low-level
shear, outside of the composite warm front/remnant outflow boundary,
should be modest, elongated and nearly straight-line hodographs will
favor potential for a couple, long-track splitting supercells. With
steep mid-level lapse rates impinging from the west, the setup may
be favorable for a mesoscale corridor of enhanced large hail
potential. For this cycle, have added a sig severe hail area.

Farther east-southeast towards the central Gulf Coast, low-level
shear will be stronger within the warm conveyor, but weak mid-level
lapse rates will limit destabilization. With sufficient low-level
shear to support updraft rotation, any supercell that develops in
this regime could produce a tornado. Convective mode will likely
tend to become messy rather quickly, as thunderstorm mergers result
in multiple clusters capable of producing damaging winds.
Uncertainty over timing of warm-sector surface-based storms further
limits confidence in highlighting a mesoscale corridor of greater
tornado potential. Still, at least a low-probability threat for
tornadoes and damaging winds should persist into Friday night across
parts of MS/AL, perhaps as far east as GA late.

..Grams.. 03/07/2024

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