960
ACUS01 KWNS 271952
SWODY1
SPC AC 271951
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0251 PM CDT WED MAY 27 2026
VALID 272000Z - 281200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE
OHIO VALLEY AND MID ATLANTIC...
..SUMMARY
SCATTERED SEVERE THUNDERSTORMS REMAIN POSSIBLE ACROSS PARTS OF THE
OHIO VALLEY AND MID-ATLANTIC THIS AFTERNOON AND EVENING. STRONG TO
SEVERE GUSTS CAPABLE OF PRODUCING WIND DAMAGE SHOULD BE THE PRIMARY
HAZARD, BUT ISOLATED HAIL MAY ALSO OCCUR.
..20Z UPDATE
THE PREVIOUS FORECAST (SEE BELOW) REMAINS GENERALLY ON TRACK (PLEASE
SEE MCD 876 FOR SHORT-TERM SEVERE TRENDS IN THE MID-ATLANTIC
REGION). THE PRIMARY CHANGE TO THE OUTLOOK WAS TO DROP SEVERE WIND
AND HAIL PROBABILITIES ACROSS THE TX PANHANDLE. HERE, CONVECTION HAS
FAILED TO DEEPEN, WITH WIDESPREAD CLOUD COVER BECOMING MORE
PREVALENT DURING THE DIURNAL HEATING MAXIMUM. IT IS UNCLEAR IF CELLS
CAN CONGEAL INTO LARGER STORM CORES CAPABLE OF PRODUCING SEVERE WIND
AND HAIL. HOWEVER, ENOUGH OVERLAPPING VERTICAL ORIENTED LOW-LEVEL
VORTICITY AND 0-3 KM CAPE EXISTS TO SUPPORT A LANDSPOUT, SO 2
PERCENT TORNADO PROBABILITIES HAVE BEEN MAINTAINED GIVEN THE
PRESENCE OF CONVECTIVE UPDRAFTS.
..SQUITIERI.. 05/27/2026
PREV DISCUSSION
/ISSUED 1120 AM CDT WED MAY 27 2026/
..OHIO VALLEY/MID-ATLANTIC
30-40 KT OF MID-LEVEL WESTERLY FLOW WILL BE PRESENT TODAY ACROSS
PARTS OF THE OH VALLEY AND MID-ATLANTIC, SANDWICHED BETWEEN AN UPPER
TROUGH OVER ONTARIO/QUEBEC AND A MID-LEVEL ANTICYCLONE CENTERED OVER
THE WESTERN ATLANTIC. A WEST-EAST ORIENTED FRONT, MODULATED BY
ONGOING CONVECTION, WILL SERVE AS A FOCUS AND NORTHERN LIMIT FOR
SEVERE POTENTIAL. LATEST SURFACE OBSERVATIONS SHOW A RATHER MOIST
LOW-LEVEL AIRMASS PRESENT ALONG/SOUTH OF THIS BOUNDARY (ALSO
REFERENCE THE 12Z OBSERVED SOUNDINGS FROM IAD/RNK), WITH SURFACE
DEWPOINTS GENERALLY IN THE MID 60S TO LOW 70S. LAPSE RATES ALOFT ARE
EXPECTED TO REMAIN POOR, AND PERSISTENT CLOUD COVER WILL SLOW
DAYTIME HEATING.
STILL, WEAK TO MODERATE INSTABILITY (MLCAPE 500-1500 J/KG) COUPLED
WITH 30-40 KT OF WESTERLY DEEP-LAYER SHEAR WILL SUPPORT ORGANIZED
THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING AS A WEAK MID-LEVEL
SHORTWAVE TROUGH MOVES EASTWARD ACROSS THE OH VALLEY/MID-ATLANTIC. A
MIX OF MULTICELLS AND MARGINAL SUPERCELL STRUCTURES IS ANTICIPATED
ALONG/SOUTH OF THE FRONT, WITH SCATTERED DAMAGING WINDS THE MAIN
SEVERE RISK. SOME HAIL COULD ALSO OCCUR WITH THE STRONGEST CORES.
THE SLIGHT RISK FOR SEVERE/DAMAGING WINDS HAS BEEN EXPANDED WESTWARD
INTO PARTS OF WV AND VICINITY, WHERE A FAVORABLE
ENVIRONMENT/CONVECTIVE EVOLUTION SHOULD OCCUR, SIMILAR TO LOCATIONS
FARTHER EAST IN VA/MD ALONG/SOUTH OF ONGOING PRECIPITATION.
..PACIFIC NORTHWEST/NORTHERN ROCKIES
A CLOSED MID/UPPER-LEVEL LOW IS NOT EXPECTED TO MOVE MUCH OVER CA/NV
TODAY. ENHANCED EAST-SOUTHEASTERLY MID-LEVEL FLOW AND MODEST
LARGE-SCALE ASCENT TO THE NORTH OF THIS CYCLONE WILL LIKELY SUPPORT
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS THIS AFTERNOON AND
EVENING ACROSS PARTS OF OR/ID AND WESTERN MT. COOL TEMPERATURES
ALOFT AND ADEQUATE LOW-LEVEL MOISTURE SHOULD SUPPORT AT LEAST WEAK
INSTABILITY AS FILTERED DAYTIME HEATING OCCURS. AS LOW-LEVEL LAPSE
RATES STEEPEN WITH THE WELL-MIXED BOUNDARY LAYER, ISOLATED SEVERE
GUSTS APPEAR POSSIBLE WITH THE HIGH-BASED CONVECTION THAT DEVELOPS
AND SPREADS WEST-NORTHWESTWARD THROUGH THE AFTERNOON/EVENING. SOME
GUSTS MAY REACH UP TO 70-75 MPH ON A LOCALIZED BASIS, BUT CONFIDENCE
IN A MORE FOCUSED CORRIDOR OF SEVERE WINDS REMAINS TOO LOW TO
INCLUDE GREATER PROBABILITIES AT THIS TIME. ISOLATED HAIL MAY ALSO
OCCUR.
..COASTAL TEXAS TO THE ARKLATEX
AN EXPANSIVE MCS HAS MOVED OFFSHORE FROM COASTAL TX INTO THE WESTERN
GULF LATE THIS MORNING. A LEADING MCS/OUTFLOW IS ALSO PRESENT ACROSS
PARTS OF SOUTHERN/CENTRAL LA. CURRENT EXPECTATIONS ARE FOR LIMITED
REDEVELOPMENT AND SEVERE RISK THROUGH THE PERIOD IN THE WAKE OF THIS
ONGOING ACTIVITY ACROSS COASTAL TX/SOUTHERN LA. HOWEVER, THERE MAY
BE AN OPPORTUNITY FOR MODEST DESTABILIZATION NEAR AN MCV ACROSS THE
ARKLATEX VICINITY THIS AFTERNOON. FAVORABLE/VEERING WIND PROFILES
WITH HEIGHT THROUGH MID LEVELS AND RELATED DEEP-LAYER SHEAR (SEE
RECENT VWPS FROM KSHV) WOULD CONDITIONALLY SUPPORT ORGANIZED
THUNDERSTORMS THIS AFTERNOON, ASSUMING SUFFICIENT INSTABILITY CAN
DEVELOP AMID WIDESPREAD CLOUD COVER. HAVE OPTED TO ADD A FOCUSED
MARGINAL RISK ACROSS PORTIONS OF THE ARKLATEX AND VICINITY FOR THIS
POTENTIAL, WITH BOTH OCCASIONAL DAMAGING WINDS AND A TORNADO OR TWO
POSSIBLE WITH THE STRONGER CELLS THAT DEVELOP.
..UPPER MIDWEST/WESTERN GREAT LAKES
MODEST NORTH-NORTHWESTERLY MID-LEVEL FLOW SHOULD EXIST TODAY ACROSS
THE UPPER MIDWEST AND WESTERN GREAT LAKES. WITH CONTINUED DAYTIME
HEATING, MODERATE INSTABILITY SHOULD DEVELOP ALONG/SOUTH OF A WEAK
SURFACE FRONT. THUNDERSTORMS THAT INITIATE ALONG/NEAR THE FRONT THIS
AFTERNOON COULD POSE AN ISOLATED THREAT FOR SEVERE HAIL AND DAMAGING
WINDS, PARTICULARLY ACROSS PARTS OF WI WHERE THE BEST CONVECTIVE
SIGNAL EXISTS IN VARIOUS SHORT-TERM MODEL GUIDANCE. HOWEVER, OVERALL
CONVECTIVE COVERAGE IS UNCERTAIN, AS LARGE-SCALE ASCENT SHOULD
REMAIN FAIRLY WEAK.
..SOUTHERN HIGH PLAINS
COOL TEMPERATURES ALOFT IN ASSOCIATION WITH A WEAK MID-LEVEL TROUGH
OVER THE SOUTHERN HIGH PLAINS SHOULD AID AT LEAST WEAK
DESTABILIZATION THIS AFTERNOON ACROSS PARTS OF NORTHWEST TX INTO THE
TX PANHANDLE AND FAR WESTERN OK. WHILE LOW-LEVEL MOISTURE WILL
REMAIN FAIRLY MUTED AND DEEP-LAYER SHEAR RATHER MODEST, A FEW
STRONGER THUNDERSTORMS CAPABLE OF PRODUCING ISOLATED HAIL/GUSTY
WINDS AND PERHAPS A LANDSPOUT MAY OCCUR.
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