496
ACUS02 KWNS 310606
SWODY2
SPC AC 310604
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0104 AM CDT MON AUG 31 2026
VALID 011200Z - 021200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
CENTRAL NEW YORK INTO CENTRAL AND EASTERN PENNSYLVANIA AND NEW
JERSEY...
..SUMMARY
SCATTERED STRONG TO SEVERE STORMS ARE POSSIBLE TUESDAY OVER PARTS OF
NEW YORK, PENNSYLVANIA AND NEW JERSEY. ISOLATED SEVERE STORMS MAY
ALSO EXTEND WESTWARD INTO NEBRASKA.
..SYNOPSIS
AN UPPER RIDGE WILL PREVAIL OVER THE CENTRAL MS VALLEY TO THE
CENTRAL APPALACHIANS WHILE A NEGATIVELY TILTED UPPER TROUGH
AMPLIFIES OVER THE INTERIOR WEST TOMORROW (TUESDAY). MULTIPLE
MID-LEVEL IMPULSES WILL PIVOT AROUND THE UPPER RIDGE, FROM THE
CENTRAL PLAINS TO THE MID-ATLANTIC, SUPPORTING MULTIPLE THUNDERSTORM
CLUSTERS ALL ALONG THE RIDGE. ACROSS THE NORTHEAST, MULTIPLE
PRONOUNCED MID-LEVEL IMPULSES, PRECEDED BY SEASONABLY COOLER
MID-LEVEL TEMPERATURES AND STRONGER WESTERLY FLOW ATOP RICH
LOW-LEVEL MOISTURE, WILL PROMOTE STRONG THUNDERSTORM POTENTIAL, SOME
OF WHICH MAY BE SEVERE. ISOLATED SEVERE THUNDERSTORMS ARE ALSO
POSSIBLE ALONG THE PERIPHERY OF THE UPPER RIDGE FROM THE MIDWEST TO
GREAT LAKES.
..PARTS OF THE NORTHEAST
WEAK SURFACE TROUGHING WILL DEVELOP ACROSS THE LOWER HUDSON VALLEY,
ALONG WITH THE DEVELOPMENT OF A DIFFUSE WARM FRONT BENEATH THE
NORTHEAST PERIPHERY OF THE UPPER RIDGE. GUIDANCE CURRENTLY SUGGESTS
THAT AT LEAST TWO IMPULSES MAY SUPPORT THUNDERSTORM DEVELOPMENT OVER
SOUTHERN NEW ENGLAND INTO THE NORTHERN MID-ATLANTIC. THE FIRST AND
MORE SUBTLE IMPULSE WILL OVERSPREAD THE REGION DURING THE DAY,
ACCOMPANIED BY ENOUGH UPPER SUPPORT TO PROMOTE SPARSE THUNDERSTORM
DEVELOPMENT OVER THE TRI-STATE AREA. BY AFTERNOON, 7 C/KM MID-LEVEL
LAPSE RATES WILL OVERSPREAD 70S F SURFACE DEWPOINTS, RESULTING IN
2000-3000 J/KG MLCAPE AMID 40+ KTS OF EFFECTIVE BULK SHEAR. FORECAST
SOUNDINGS ALSO SHOW APPRECIABLY CURVED, SIZEABLE LOW-LEVEL
HODOGRAPHS. AS SUCH, A COUPLE OF SUPERCELLS WILL BE POSSIBLE,
ACCOMPANIED BY A RISK OF SEVERE HAIL/WIND AND PERHAPS A TORNADO.
LATER OVERNIGHT, THE APPROACH OF A MORE PRONOUNCED MID-LEVEL IMPULSE
IS EXPECTED. AS THIS OCCURS, THUNDERSTORMS SHOULD DEVELOP AROUND THE
GREAT LAKES AND TRAVERSE THE UPPER RIDGE, MOVING SOUTHEAST TOWARD
THE MID-ATLANTIC COASTLINE. DESPITE NOCTURNAL COOLING, THE RICH
MOISTURE IN PLACE WILL LIMIT STABILIZATION TO A DEGREE. SHOULD
STRONGER STORMS PERSIST, A FEW INSTANCES OF SEVERE WIND AND HAIL ARE
POSSIBLE, ESPECIALLY OVER CENTRAL AND SOUTHERN PA.
..PORTIONS OF THE CENTRAL PLAINS TO GREAT LAKES
ONE MID-LEVEL IMPULSE WILL EJECT INTO THE CENTRAL PLAINS WHILE
ANOTHER LOW-AMPLITUDE UPPER TROUGH TRAVERSES THE GREAT LAKES THROUGH
THE PERIOD. BY EVENING, A WEAK SURFACE CYCLONE WILL DEVELOP OVER THE
CENTRAL PLAINS WHILE A DIFFUSE WARM FRONT BECOMES SITUATED OVER
NORTHEASTERN NE TO CENTRAL WI. SURFACE DEWPOINTS MAY REACH UP TO THE
MID 70S F ALONG PORTIONS OF THIS WARM FRONT, YIELDING OVER 3000 J/KG
MLCAPE OVER SEVERAL LOCALES GIVEN 7-8 C/KM MID-LEVEL LAPSE RATES
OVERSPREADING THIS BOUNDARY. A BELT OF 50+ KT WEST-SOUTHWESTERLY 500
MB FLOW MAY ALSO OVERLAP WITH THE AFOREMENTIONED MID-LEVEL LAPSE
RATES GIVEN THE APPROACH OF THE EMBEDDED IMPULSE, SUPPORTING 40-50
KTS OF EFFECTIVE BULK SHEAR AND MODESTLY CURVED/ELONGATED
HODOGRAPHS.
GIVEN THE STRONG OVERLAPPING BUOYANCY AND VERTICAL WIND SHEAR, ANY
STORM THAT CAN MATURE AND BECOME SUSTAINED MAY BECOME MULTICELLULAR
OR SUPERCELLULAR, ACCOMPANIED BY A SEVERE WIND/HAIL THREAT. AT THE
MOMENT, STORM COVERAGE SHOULD BE SPARSE, SINCE UPPER SUPPORT WITH
THE GREAT LAKES MID-LEVEL TROUGH SHOULD ONLY GRAZE THE WARM FRONTAL
ZONE, AND THE APPROACH OF THE CENTRAL PLAINS IMPULSE SHOULD OCCUR
LATE IN THE PERIOD. THEREFORE, DESPITE THE FAVORABLE CONVECTIVE
ENVIRONMENT, PROBABILITIES HAVE BEEN MAINTAINED AT CATEGORY
1/MARGINAL RISK.
.. SOUTHERN TX/LA
TROPICAL CYCLONE FORMATION IS POSSIBLE WITHIN THE NEXT 48 HOURS
ALONG THE LA COASTLINE (PLEASE SEE THE NATIONAL HURRICANE CENTER
OUTLOOKS FOR MORE DETAILS). THIS DISTURBANCE WILL CONTINUE TO TRACK
WEST-NORTHWESTWARD ALONG THE LA/TX COASTLINES THROUGH TUESDAY.
VERTICAL SHEAR PROFILES ACCOMPANYING THIS DISTURBANCE ARE FORECAST
TO BE QUITE WEAK, PRECLUDING TORNADO PROBABILITIES THIS OUTLOOK.
..SQUITIERI.. 08/31/2026
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