539
ACUS02 KWNS 261715
SWODY2
SPC AC 261713
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1213 PM CDT WED AUG 26 2026
VALID 271200Z - 281200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE MID-ATLANTIC AND NORTHEAST...
..SUMMARY
SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS PARTS
OF THE NORTHEAST ON THURSDAY. DAMAGING WIND, HAIL AND A TORNADO OR
TWO MAY ACCOMPANY THESE STORMS. STRONG WIND GUSTS AND HAIL ALSO MAY
OCCUR OVER PARTS OF THE CENTRAL PLAINS, AND THE NORTHERN ROCKIES
VICINITY.
..MID-ATLANTIC/NORTHEAST
UPPER TROUGHING WILL PERSIST OVER THE EASTERN U.S., WITH THE TROUGH
AXIS REMAINING ROUGHLY ORIENTED FROM THE LOWER GREAT LAKES TOWARD
THE CENTRAL/SOUTHERN APPALACHIANS. THIS WILL RESULT IN MODEST
SOUTHWESTERLY DEEP-LAYER FLOW ACROSS REGION, WITH SOMEWHAT STRONG
VERTICAL WIND PROFILES EXPECTED ACROSS THE NORTHEAST (AND DECREASING
WITH SOUTHWARD EXTENT ACROSS CENTRAL/SOUTHERN APPALACHIANS). A
SURFACE TROUGH/WEAK FRONT WILL EXTEND FROM THE UPPER OH VALLEY
SOUTHWARD TOWARD NORTHERN GA THURSDAY MORNING, WITH THIS FEATURE
DRIFTING EASTWARD THROUGH EARLY FRIDAY. SOUTHERLY LOW-LEVEL FLOW
EAST OF THE SURFACE TROUGH/BOUNDARY, WILL MAINTAIN A SEASONALLY
MOIST BOUNDARY LAYER (60S F DEWPOINTS). THIS WILL SUPPORT MODERATE
DESTABILIZATION ACROSS THE REGION, WITH POCKETS OF STRONG
INSTABILITY POSSIBLE NEAR/WEST OF THE I-95 CORRIDOR FROM NORTHERN VA
INTO SOUTHERN/CENTRAL NY.
VERTICALLY VEERING WIND PROFILES ARE EVIDENT IN FORECAST SOUNDINGS,
WITH AROUND 25-35 KT EFFECTIVE SHEAR MAGNITUDES SUGGESTING ORGANIZED
STORMS STRUCTURES AND POSSIBLE TRANSIENT SUPERCELLS. DAMAGING WINDS
AND OCCASIONAL HAIL WILL BE THE MAIN HAZARDS WITH STORMS THROUGH
THURSDAY EVENING. LOW-LEVEL HODOGRAPHS ARE SOMEWHAT SMALL, BUT
FAVORABLY CURVED, WITH 0-1 KM SRH APPROACHING 100 M2/S2 WHERE BACKED
LOW-LEVEL WINDS PERSIST. GIVEN THE MOIST BOUNDARY LAYER AND
SUFFICIENT STEEP LOW-LEVEL LAPSE RATES, A TORNADO OR TWO ALSO WILL
BE POSSIBLE.
VERTICAL SHEAR DECREASES WITH SOUTHWARD EXTENT ACROSS THE
APPALACHIANS. HOWEVER, HIGH PW AND SUFFICIENT INSTABILITY WILL EXIST
THAT THUNDERSTORM CLUSTERS COULD PRODUCE WET MICROBURSTS AND
SPORADIC WIND DAMAGE OF MARGINAL HAIL AS FAR SOUTH AS NORTHEAST
TN/NORTHWEST NC.
..CENTRAL PLAINS
NORTHWESTERLY FLOW ALOFT WILL PERSIST OVER THE REGION ON THURSDAY AS
THE WESTERN UPPER RIDGING BEGINS TO SHIFT EAST OVER THE HIGH PLAINS.
THIS WILL LIKELY SUPPRESS CONVECTIVE COVERAGE SOMEWHAT. HOWEVER,
MODEST VORTICITY MAXIMA ROTATING THROUGH NORTHWESTERLY FLOW ALOFT
AND STRONGER HEATING ACROSS THE MODESTLY MOIST AIRMASS, ALONG WITH
POSSIBLE OUTFLOW FROM PRIOR CONVECTION WILL SUPPORT ISOLATED
THUNDERSTORM DEVELOPMENT FROM THE BLACK HILLS SOUTHEAST INTO
NEBRASKA. ELONGATED HODOGRAPHS AND EFFECTIVE SHEAR AROUND 35+ KT
AMID STEEP MIDLEVEL LAPSE RATES SUGGEST LARGE HAIL WILL BE POSSIBLE,
WITH SOME POTENTIAL FOR HAIL GREATER THAN 2 INCH DIAMETER. OVERALL
STORM COVERAGE IS EXPECTED TO REMAIN LOW, PRECLUDING HIGHER SEVERE
PROBABILITIES.
ADDITIONAL THUNDERSTORMS ARE POSSIBLE WITH UPSLOPE FLOW ALONG THE CO
FOOTHILLS VICINITY. WEAKER VERTICAL SHEAR IS EXPECTED COMPARED TO
FURTHER NORTH, BUT THE ENVIRONMENT WILL STILL SUPPORT MARGINAL HAIL
WITH STRONGER UPDRAFTS.
..NORTHERN ROCKIES
SOUTHWESTERLY FLOW ALOFT WILL INCREASE AS AN UPPER SHORTWAVE TROUGH
MOVES EASTWARD FROM THE PACIFIC NORTHWEST INTO MT AND ALBERTA. STEEP
MIDLEVEL LAPSE RATES WILL SUPPORT MODEST DESTABILIZATION BY EARLY
AFTERNOON AND ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER HIGHER TERRAIN. STRONG HEATING WILL RESULT IN DEEP
BOUNDARY LAYER MIXING AND STEEP LOW-LEVEL LAPSE RATES. GIVEN
STRONGER FLOW ALOFT, ISOLATED STRONG TO SEVERE WIND GUSTS WILL BE
POSSIBLE AS CONVECTION DEVELOPS EAST/NORTHEAST THROUGH EARLY
EVENING.
..LEITMAN.. 08/26/2026
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