979
ACUS02 KWNS 160633
SWODY2
SPC AC 160631
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1231 AM CST MON DEC 16 2024
VALID 171200Z - 181200Z
..NO SEVERE THUNDERSTORM AREAS FORECAST
..SUMMARY
THUNDERSTORMS ARE EXPECTED FROM THE SOUTHERN PLAINS TO THE LOWER
OHIO AND TENNESSEE VALLEY VICINITIES AND ACROSS FLORIDA ON TUESDAY.
SEVERE-THUNDERSTORM CHANCES ARE LOW AT THIS TIME.
..EASTERN OK/ARKLATEX/OZARKS VICINITY
AN UPPER TROUGH WILL DEEPEN AS IT MOVES ACROSS THE PLAINS TO THE MS
VALLEY VICINITY ON TUESDAY. A 500 MB JET MAX AROUND 50-70 KT WILL
BECOME ORIENTED FROM EASTERN OK INTO THE OHIO VALLEY/LOWER GREAT
LAKES AREA AFTER 06Z, AND STRONGER HEIGHT FALLS ARE NOT EXPECTED TO
OVERSPREAD THE REGION UNTIL THE NIGHTTIME HOURS. AT THE SURFACE, 50S
TO LOW/MID 60S F DEWPOINTS ARE EXPECTED ACROSS SOUTH/EAST TX INTO
THE MID-SOUTH VICINITY. A STRONG COLD FRONT WILL TRACK SOUTHEAST
ACROSS KS/OK DURING THE EVENING, AND BY 06Z BE POSITIONED FROM
NORTHERN AR INTO SOUTHEAST OK AND NORTH-CENTRAL TX. THIS BOUNDARY
WILL BECOME A FOCUS FOR INCREASING ISENTROPIC ASCENT AND ISOLATED TO
SCATTERED THUNDERSTORMS DURING THE OVERNIGHT/EARLY WEDNESDAY PERIOD.
NEUTRAL HEIGHT TENDENCIES WILL LIKELY SUPPRESS CONVECTION DURING THE
DAY ACROSS MUCH OF THE AREA. AS CONVECTION DEVELOPS ALONG THE
ADVANCING COLD FRONT OVERNIGHT, UNCERTAINTY REMAINS REGARDING ANY
SURFACE-BASED INSTABILITY OVERLAPPING WITH STRONGER VERTICAL SHEAR
(WHICH DECREASES RAPIDLY WITH SOUTHWARD EXTENT). FORECAST SOUNDINGS
VARY ACROSS FORECAST GUIDANCE, BUT AT LEAST WEAK ELEVATED
INSTABILITY IS EXPECTED DRIVEN BY COOLING ALOFT. STRONGER ELEVATED
CORES COULD PRODUCE SMALL HAIL, GIVEN FORECAST LAPSE RATES AROUND
6.8-7 C/KM AMID 30+ KT EFFECTIVE SHEAR MAGNITUDES (ESPECIALLY FROM
SOUTHEAST OK INTO AR). OVERALL, SEVERE POTENTIAL APPEARS QUITE
CONDITIONAL FOR THE LAST 3-6 HOURS OF THE FORECAST PERIOD. WILL HOLD
OFF ON INCLUDING LOW-END HAIL PROBABILITIES, THOUGH A MARGINAL
(LEVEL 1 OF 5) RISK MAY BE NEEDED IN LATER OUTLOOKS DEPENDING ON
FORECAST TRENDS.
..FL PENINSULA
ISOLATED THUNDERSTORMS ARE EXPECTED ON TUESDAY AS A MOIST AIRMASS
AND AT LEAST WEAK INSTABILITY OVERSPREAD THE REGION. ONSHORE,
EASTERLY LOW-LEVEL FLOW WILL PROVIDE CONVERGENCE ALONG AN INVERTED
SURFACE TROUGH. GIVEN SUFFICIENT DESTABILIZATION, THIS WILL SUPPORT
DEVELOPMENT OF THUNDERSTORMS MOVING ONSHORE THROUGH EVENING. WEAK
0-6 KM BULK SHEAR (LESS THAN 20 KT) WILL PRECLUDE ORGANIZED
CONVECTION, AND SEVERE STORMS ARE NOT EXPECTED.
..LEITMAN.. 12/16/2024
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