149
ACUS02 KWNS 071730
SWODY2
SPC AC 071729
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1229 PM CDT WED MAY 07 2025
VALID 081200Z - 091200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE SOUTHERN
APPALACHIANS AND RIO GRANDE VALLEY...
..SUMMARY
SCATTERED DAMAGING WINDS AND SEVERE HAIL ARE POSSIBLE OVER THE
SOUTHERN APPALACHIANS ON THURSDAY AFTERNOON TO EARLY EVENING. A
SWATH OF LARGE HAIL AND SEVERE WIND IS POSSIBLE ALONG THE RIO GRANDE
VALLEY FROM MID-AFTERNOON TO EVENING.
..SYNOPSIS
AN ELONGATED, POSITIVE-TILT MID/UPPER TROUGH FROM SOUTHEAST CANADA
TO THE RIO GRANDE WILL SLOWLY PROGRESS EAST ON THURSDAY. AT LEAST A
TRIO OF EMBEDDED SHORTWAVE IMPULSES WILL AID IN CORRIDORS OF MODEST
LARGE-SCALE ASCENT, AMID A PERVASIVE SWATH OF 35-50 KT 500-MB
WEST-SOUTHWESTERLIES ACROSS THE SOUTH INTO THE EAST. GIVEN THE
HIGHLY POSITIVE-TILT ORIENTATION OF THE TROUGH, ATTENDANT SURFACE
REFLECTIONS WILL REMAIN WEAK. A MINOR SURFACE WAVE OVER THE
MID-SOUTH SHOULD DECAY BY EARLY EVENING, WHILE A SEPARATE LOW DRIFTS
NORTHEAST FROM THE LEE OF THE SOUTHERN APPALACHIANS TO VA.
..MID-SOUTH TO SOUTHERN APPALACHIANS
MULTIPLE CORRIDORS OF SCATTERED THUNDERSTORM DEVELOPMENT ARE
EXPECTED BY THURSDAY AFTERNOON, AHEAD OF A SHORTWAVE IMPULSE
DRIFTING FROM THE OZARKS ACROSS A PORTION OF THE MID-SOUTH.
LINGERING ACTIVITY/CLOUD COVER DURING THE MORNING WILL SERVE AS THE
NORTHERN LIMITER TO SEVERE POTENTIAL, ALONG WITH WEAKER DEEP-LAYER
SHEAR CLOSER TO THE TROUGH. THE MOST LIKELY ZONE FOR A SCATTERED
SEVERE HAIL AND DAMAGING WIND THREAT APPEARS TO BE ACROSS THE
SOUTHERN APPALACHIANS VICINITY WHERE MLCAPE OF 1000-1500 J/KG AND
30-40 KT EFFECTIVE BULK SHEAR ARE ANTICIPATED. HERE, A FEW
SUPERCELLS MAY CONGEAL INTO AN ORGANIZED CLUSTER OR TWO. FARTHER
WEST, LESSER VALUES OF INSTABILITY AND SHEAR SHOULD YIELD A MORE
ISOLATED/MARGINAL SEVERE THREAT.
..TX RIO GRANDE VALLEY
A LOW-AMPLITUDE SHORTWAVE IMPULSE SHOULD PROGRESS FROM NORTHERN
CHIHUAHUA ALONG THE RIO GRANDE. NUMEROUS THUNDERSTORMS ARE EXPECTED
AHEAD OF THE IMPULSE ACROSS THE SOUTHERN TRANS-PECOS/BIG BEND BY
MID-AFTERNOON AND ADJACENT COAHUILA. UNCERTAINTY INCREASES WITH HOW
THIS ACTIVITY WILL EVOLVE DOWNSTREAM THURSDAY EVENING, POTENTIALLY
REMAINING PRIMARILY ACROSS NORTHEAST MEXICO OR GROWING UPSCALE
ACROSS THE LOWER RIO GRANDE VALLEY INTO DEEP SOUTH TX AS IT IMPINGES
ON RICHER LOW-LEVEL MOISTURE. WITH LOW-LEVEL NORTHEASTERLIES BENEATH
MID/UPPER-LEVEL WEST-SOUTHWESTERLIES, AN ELONGATED/NEARLY
STRAIGHT-LINE HODOGRAPH IS EXPECTED. THIS SHOULD FOSTER SPLITTING
SUPERCELL STRUCTURES, WHICH COULD CONGEAL INTO A CLUSTER/SMALL MCS.
THE PRIMARY LIMITING FACTOR TO MORE ROBUST INTENSITY WILL BE A LACK
OF STEEP MID-LEVEL LAPSE RATES AMID WEAK WARM ADVECTION. STILL,
ENOUGH SIGNAL EXISTS TO WARRANT A LEVEL 2/SLGT RISK.
..SOUTHERN MID-ATLANTIC
MODEST MID-LEVEL FORCING FOR ASCENT SHOULD PROMOTE ISOLATED TO
SCATTERED THUNDERSTORMS DEVELOPING OFF THE CENTRAL APPALACHIANS AND
BLUE RIDGE MOUNTAINS ON THURSDAY AFTERNOON. A WELL-MIXED BOUNDARY
LAYER WITH WEAK MLCAPE AND MODERATE EFFECTIVE SHEAR WILL ALLOW FOR A
FEW TRANSIENT/WEAKLY ORGANIZED CELLS DURING THE AFTERNOON. THIS
COULD PROMOTE SMALL HAIL AMID WEAK MID-LEVEL LAPSE RATES AND SUPPORT
A PRIMARY THREAT OF LOCALIZED DAMAGING WINDS.
..SOUTHERN ATLANTIC COAST
SUFFICIENT MID-LEVEL WESTERLIES ARE EXPECTED TO SUPPORT A FEW WEAKLY
ORGANIZED STORMS ALONG THE SEA BREEZE BOUNDARY ON THURSDAY
AFTERNOON. MID-LEVEL TEMPERATURES SHOULD REMAIN COLD ENOUGH TO
SUPPORT AN ISOLATED SEVERE HAIL THREAT. A WARM/MOIST BOUNDARY LAYER
WILL ALSO FOSTER ISOLATED STRONG TO SEVERE GUSTS.
..GRAMS.. 05/07/2025
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