SPC AC 160056
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0656 PM CST Sat Feb 15 2025
Valid 160100Z - 161200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN THE TN/LOWER
MS VALLEYS AND THE DEEP SOUTH...
...SUMMARY...
Severe thunderstorms are expected through early morning Sunday
across parts of the Tennessee/Lower Mississippi Valleys and the Deep
South. Tornadoes, a few of which could be strong, and scattered to
widespread damaging winds should be the primary threats.
...TN/Lower MS Valleys and the Deep South...
Broken linear convection is ongoing from the Mid-South to the Lower
Sabine Valley, along and just ahead of a surface cold front that is
expected to move east tonight. A relatively broad warm-moist sector
heated into the 70s and low 80s earlier, and has supported a plume
of MLCAPE 500-1500 J/kg. As a well-defined shortwave trough over the
Lower MO Valley to northeast TX progresses east into the Central OH
Valley and Deep South, an extensive QLCS will evolve from the TN
Valley to the central Gulf Coast. Pre-QLCS convection across LA
should persist with eastern extent across the Gulf Coast States.
Very strong 850-700 mb winds (65-80 kt) should be prominent from the
Ark-La-Miss to central parts of MS/AL northward. This flow regime
should support widespread strong gusts with embedded severe swaths,
yielding scattered to widespread damaging winds, along with a threat
for mesovortex tornadoes. After coordination with WFO BMX, have
expanded the level 3-ENH risk northeastward in AL. The fast-moving
QLCS will eventually outpace the warm-moist sector in the TN
Valley/southern Appalachian vicinity.
Farther south, the 00Z JAN sounding sampled a more deeply mixed air
mass than progged by operational guidance, with mean-mixing ratios
near 11 g/kg. Rich boundary-layer moisture closer to the Gulf Coast
suggests that semi-discrete supercells merging into the southern
portion of the QLCS would be the more favored scenario for a few
longer-lasting/strong tornadoes overnight.
..Grams.. 02/16/2025
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NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z