370
ACUS02 KWNS 270521
SWODY2
SPC AC 270520
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1220 AM CDT MON JUL 27 2026
VALID 281200Z - 291200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE SOUTHERN
MID-ATLANTIC INTO THE CAROLINAS AND CENTRAL AND SOUTHERN
APPALACHIANS...
..SUMMARY
SEVERE THUNDERSTORMS CAPABLE OF DAMAGING WINDS AND ISOLATED HAIL ARE
POSSIBLE FROM THE SOUTHERN MID-ATLANTIC INTO THE CAROLINAS AND
CENTRAL AND SOUTHERN APPALACHIANS TUESDAY INTO TUESDAY EVENING.
ISOLATED SEVERE WIND GUSTS AND LARGE HAIL MAY OCCUR IN THE CENTRAL
HIGH PLAINS.
..SYNOPSIS
CONSIDERABLE TROUGH AMPLIFICATION IS FORECAST OVER THE EASTERN CONUS
THIS PERIOD, AIDED BY THE PROPAGATION OF THE MID/UPPER-LEVEL JET
STREAKS FROM THE GREAT LAKES AND OH VALLEY THROUGH VA AND NC. A
SERIES OF VORTICITY MAXIMA IS FORECAST ON THE CYCLONIC SIDE OF THE
JET STREAKS, WHICH WILL ENHANCE FORCING FOR ASCENT OVER THE CENTRAL
APPALACHIANS INTO THE MID-ATLANTIC. AT THE SURFACE, THE PRIMARY LOW
PRESSURE IS EXPECTED TO DEEPEN OVER THE DELMARVA WITH A SECONDARY
CYCLONE OVER WESTERN NY. A LEE TROUGH WILL EXTEND FROM THE DELMARVA
LOW SOUTH-SOUTHWEST ALONG THE PIEDMONT, AHEAD OF A COLD FRONT MOVING
THROUGH THE TN VALLEY AND CENTRAL AND SOUTHERN APPALACHIANS.
..MID-ATLANTIC INTO THE SOUTHERN APPALACHIANS
SHOWERS AND THUNDERSTORMS (SOME POTENTIALLY SEVERE WITH DAMAGING
WINDS) ARE EXPECTED TO BE ONGOING TUESDAY MORNING FROM THE LOWER
GREAT LAKES INTO THE CENTRAL APPALACHIANS. THE LONGEVITY AND AREAL
EXTENT OF THE EARLY-DAY STORMS WILL BE A DETERMINANT IN WHERE MORE
ROBUST AIR MASS DESTABILIZATION WILL TAKE PLACE DURING THE
AFTERNOON. THE 00Z HREF CALIBRATED THUNDER PROBABILITIES SUGGEST THE
MOST LIKELY AREAS FOR PERSISTENT MORNING STORMS WILL BE FROM NY AND
PA INTO THE DELMARVA AND WV. TO THE SOUTH OF THOSE LOCATIONS,
STRONGER DAYTIME HEATING APPEARS MORE PROBABLE, WHICH, COMBINED WITH
BOUNDARY-LAYER DEWPOINTS IN THE UPPER 60S TO MID 70S, WILL YIELD
MODERATE TO POTENTIALLY STRONG AFTERNOON INSTABILITY WITH MLCAPE OF
1500-2500+ J/KG.
THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
DURING THE AFTERNOON ALONG AND AHEAD OF THE COLD FRONT AND LEE
TROUGH AS BACKGROUND FORCING FOR ASCENT STRENGTHENS IN THE LEFT EXIT
REGION OF THE APPROACHING UPPER-LEVEL JET STREAK. THE PRESENCE OF
THE MID/UPPER-LEVEL WIND MAXIMA WILL YIELD LONG HODOGRAPHS WITH
SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS AND BOWING STRUCTURES. THE
STRENGTHENING SHEAR COMBINED WITH COOLING MID-LEVEL TEMPERATURES
WILL BE SUPPORTIVE OF LARGE-HAIL PRODUCTION WITH ANY SUPERCELLS THAT
FORM. OTHERWISE, DAMAGING WINDS WILL BE THE PRIMARY HAZARD,
ESPECIALLY WITH ANY STORM CLUSTERS OR BOWING LINE SEGMENTS. SOME
TORNADO THREAT COULD ALSO MATERIALIZE TUESDAY AFTERNOON INTO EVENING
NEAR AND SOUTH OF THE DELMARVA SURFACE LOW WHERE SLIGHTLY STRONGER
LOW-LEVEL SHEAR IS FORECAST.
..CENTRAL HIGH PLAINS
STRONG HEATING OF A MOIST, UPSLOPE-FLOW AIR MASS IS EXPECTED TO
YIELD A MODERATELY UNSTABLE ENVIRONMENT BY AFTERNOON WITH MLCAPE OF
1500-2500 J/KG. ISOLATED TO WIDELY SCATTERED THUNDERSTORM
DEVELOPMENT APPEARS POSSIBLE BY MID- TO LATE AFTERNOON ALONG THE
HIGH TERRAIN WITHIN A KINEMATIC ENVIRONMENT FEATURING 30-35 KT
WESTERLY DEEP-LAYER SHEAR. TRANSIENT SUPERCELL STRUCTURES APPEAR
POSSIBLE, WHICH SUGGEST SOME MARGINALLY SEVERE HAIL POTENTIAL,
DESPITE THE WARM MID-LEVEL TEMPERATURES. THERE IS SOME MODEL SIGNAL
FOR STORM CLUSTERING OVER THE ADJACENT HIGH PLAINS BY EVENING, AT
WHICH POINT THE THREAT FOR ISOLATED SEVERE WIND GUSTS WOULD
INCREASE.
..MEAD.. 07/27/2026
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