905
ACUS01 KWNS 161243
SWODY1
SPC AC 161242
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0742 AM CDT FRI OCT 16 2026
VALID 161300Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MID-ATLANTIC INTO SOUTHERN NEW ENGLAND...
..SUMMARY
THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS AND PERHAPS A
TORNADO OR TWO ARE EXPECTED ACROSS PARTS OF THE MID-ATLANTIC INTO
SOUTHERN NEW ENGLAND, MAINLY THIS AFTERNOON AND EARLY EVENING.
..MID-ATLANTIC INTO SOUTHERN NEW ENGLAND
RECENT WATER VAPOR SATELLITE IMAGERY SHOWS A PROMINENT AND
POSITIVELY TILTED UPPER TROUGH EXTENDING FROM EASTERN CANADA INTO
THE UPPER MIDWEST. THIS UPPER TROUGH WILL ADVANCE EASTWARD WHILE
AMPLIFYING OVER THE EASTERN CONUS THROUGH THE PERIOD, WITH ENHANCED
WEST-SOUTHWESTERLY LOW/MID-LEVEL FLOW EXPECTED TO OVERSPREAD MUCH OF
THE MID-ATLANTIC AND NORTHEAST. A RELATED SURFACE LOW OVER SOUTHERN
ONTARIO WILL DEVELOP EAST-NORTHEASTWARD TODAY INTO SOUTHERN QUEBEC,
AS A TRAILING COLD FRONT SWEEPS EAST-SOUTHEASTWARD ACROSS THE
EASTERN STATES. LOW-LEVEL MOISTURE IS FORECAST TO GRADUALLY INCREASE
AHEAD OF THE FRONT THROUGH THE AFTERNOON, AND MLCAPE SHOULD
GRADUALLY INCREASE INTO THE 500-1000 J/KG RANGE WITH FILTERED
DAYTIME HEATING. BUT, LAPSE RATES THROUGH LOW/MID LEVELS ARE LIKELY
TO REMAIN QUITE POOR (REFERENCE BUF/PIT/IAD 12Z OBSERVED SOUNDINGS).
THIS SHOULD TEMPER OVERALL UPDRAFT STRENGTH TO SOME EXTENT, AND
LOW-TOPPED CONVECTION WHICH DEVELOPS ALONG/NEAR THE FRONT MAY
PRODUCE LITTLE LIGHTING, ESPECIALLY WITH NORTHWARD EXTENT INTO
SOUTHERN NEW ENGLAND.
EVEN WITH THE POTENTIAL THERMODYNAMIC LIMITATIONS, FAVORABLE
DEEP-LAYER SHEAR WILL SUPPORT SOME UPDRAFT ORGANIZATION. GIVEN THE
STRENGTH OF THE LOW/MID-LEVEL FLOW, ISOLATED STRONG/GUSTY WINDS MAY
OCCUR THIS MORNING WITH ONGOING CONVECTION ALONG/NEAR THE FRONT
ACROSS WESTERN PA/NY, EVEN THOUGH INSTABILITY REMAINS VERY LIMITED.
LATEST SHORT-TERM GUIDANCE CONTINUES TO SUGGEST THAT A LOW-TOPPED
CONVECTIVE LINE WILL FURTHER DEVELOP ACROSS CENTRAL INTO EASTERN PA
AND SOUTHERN NY BY 17-21Z. CONVECTIVELY AUGMENTED WIND GUSTS CAPABLE
OF PRODUCING SCATTERED DAMAGING WINDS WILL LIKELY BE THE MAIN SEVERE
RISK AS THIS ACTIVITY SPREADS QUICKLY EASTWARD ACROSS THE NORTHERN
MID-ATLANTIC AND SOUTHERN NEW ENGLAND THROUGH EARLY EVENING. THE
GREATEST COVERAGE OF DAMAGING WINDS SHOULD FOCUS ACROSS PARTS OF
EASTERN PA INTO NJ AND SOUTHERN NY, WHERE LOCALLY GREATER
INSTABILITY IS FORECAST.
THE POTENTIAL FOR LINE-EMBEDDED MESOCIRCULATIONS IS LESS CLEAR.
WHILE SOME LOW-LEVEL SHEAR WILL BE PRESENT, THE ENHANCED LOW-LEVEL
FLOW IS FORECAST TO GRADUALLY VEER TO WEST-SOUTHWESTERLY THROUGH THE
AFTERNOON/EVENING, WHICH MAY REDUCE EFFECTIVE SRH SOMEWHAT. STILL,
AT LEAST AN ISOLATED THREAT FOR DAMAGING WINDS AND PERHAPS A TORNADO
SHOULD SPREAD TOWARDS THE COAST BEFORE CONVECTION WEAKENS THIS
EVENING DUE TO MARINE LAYER INFLUENCES AND NOCTURNAL COOLING.
OVERALL, THE ONGOING FORECAST ALIGNS REASONABLY WELL WITH RECENT
SHORT-TERM GUIDANCE/OBSERVATIONAL TRENDS, AND THEREFORE ONLY MINOR
CHANGES HAVE BEEN MADE TO SEVERE PROBABILITIES WITH THIS UPDATE.
..GLEASON/KERR.. 10/16/2026
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