046
ACUS02 KWNS 131733
SWODY2
SPC AC 131731
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1231 PM CDT MON JUL 13 2026
VALID 141200Z - 151200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN
NEW ENGLAND...
..SUMMARY
SEVERE THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON AND
EVENING ACROSS PORTIONS OF NEW ENGLAND ON TUESDAY. ADDITIONAL
STRONG-TO-SEVERE THUNDERSTORMS WILL BE POSSIBLE ACROSS PARTS OF
WESTERN AND CENTRAL MONTANA.
..SYNOPSIS
UPPER-LEVEL RIDGING WILL CONTINUE ACROSS MUCH OF THE CONUS ON
TUESDAY. A STRONG UPPER TROUGH WILL MOVE INTO NEW ENGLAND DURING THE
EVENING/OVERNIGHT ALONG WITH A SURFACE COLD FRONT. ADDITIONAL
MODERATE MID-LEVEL FLOW WILL BE PRESENT OVER THE NORTHERN ROCKIES
ALONG WITH WEAKER SHORTWAVE TROUGHS MOVING THROUGH THE REGION.
..NEW ENGLAND
STRONG NORTHWESTERLY FLOW ALOFT WILL BE PRESENT AT THE START OF THE
FORECAST PERIOD. MODELS SUGGEST THAT A SUBTLE PERTURBATION MAY BE
MOVING THROUGH THE REGION EARLY IN THE DAY. SOME CONVECTION MAY BE
ASSOCIATED WITH THIS FEATURE, THOUGH THE EXPECTATION IS THAT THIS
ACTIVITY WILL BE WEAKENING WITH TIME. ANY CLOUD COVER FROM THIS
ACTIVITY WOULD DELAY SURFACE HEATING IN SOME AREAS. NEVERTHELESS,
HEATING/MOISTENING AHEAD OF THE COLD FRONT APPEARS MORE THAN
SUFFICIENT FOR SEVERE STORM DEVELOPMENT BY LATE AFTERNOON INTO THE
EVENING. INITIAL DEVELOPMENT WILL LIKELY OCCUR IN SOUTHERN QUEBEC
ALONG THE FRONT AND MOVE INTO NEW ENGLAND. THE STRONGEST FORCING FOR
ASCENT WITHIN THE REGION WILL ALSO BE AFTER 03Z. 2500-3000 J/KG
MLCAPE NEAR THE CANADIAN BORDER DURING THE LATE AFTERNOON WITH
AROUND 2000 J/KG MLCAPE PERSISTING INTO EARLY EVENING ACROSS PARTS
OF NEW ENGLAND. LINEAR FORCING ALONG THE COLD FRONT WILL NOT BE
OVERLY STRONG AND LARGE COMPONENT OF THE 50+ KT OF EFFECTIVE SHEAR
WILL BE PERPENDICULAR TO THIS BOUNDARY. SUPERCELL STRUCTURES WILL BE
FAVORED, THOUGH BOWING STRUCTURES MAY ALSO DEVELOP DUE TO STORM
INTERACTIONS OR LOCALLY GREATER LINEAR FORCING. LARGE HAIL,
INCLUDING POTENTIAL FOR 2+ IN. WITH SUPERCELLS, IS POSSIBLE.
SEVERE/DAMAGING WINDS ARE ALSO EXPECTED. BOWING SEGMENTS THAT
DEVELOP WILL HAVE POTENTIAL FOR SIGNIFICANT WIND GUSTS. LOW-LEVEL
HODOGRAPHS WILL ALSO SUPPORT A THREAT FOR A FEW TORNADOES. A STRONG
TORNADO IS POSSIBLE, BUT WILL BE CONDITIONAL ON A DISCRETE SUPERCELL
PERSISTING INTO THE EARLY EVENING.
..MONTANA
DEVELOPMENT OF A SURFACE LOW IN PARTS OF EASTERN MONTANA/WYOMING
WILL DRAW LOW-LEVEL MOISTURE WESTWARD ALONG A STALLED SURFACE
BOUNDARY. ADDITIONALLY, MID-LEVEL MOISTURE WILL INCREASE FROM THE
SOUTHWEST AROUND THE WESTERN EDGE OF THE UPPER-LEVEL RIDGE. THIS,
COUPLED WITH A SHORTWAVE TROUGH DURING THE LATE AFTERNOON, WILL
PROMOTE WIDELY SCATTERED TO SCATTERED THUNDERSTORMS WITHIN THE
HIGHER TERRAIN OF SOUTHWEST/CENTRAL MONTANA. AROUND 30-35 KT OF
EFFECTIVE SHEAR WILL PROMOTE A MIX OF MARGINAL SUPERCELLS AND LINEAR
SEGMENTS. MOISTURE WILL BE MORE MODEST WITH WESTERN EXTENT AND
OUTFLOW PRODUCTION WILL BE MORE EFFICIENT. THIS SHOULD GENERALLY
LEAD TO MORE LINEAR MODES QUICKLY. BUOYANCY WILL ALSO BE MODEST
(750-1250 J/KG MUCAPE) GIVEN 50S F DEWPOINTS INTO WESTERN MONTANA.
NORTH OF THE SURFACE LOW THERE WILL LIKELY BE A BELT OF GREATER
SURFACE MOISTURE (LOW 60S F, POTENTIALLY) THAT ADVECTS INTO THE
HIGHER TERRAIN OF CENTRAL MONTANA. HERE, A COUPLE OF SUPERCELLS
COULD DEVELOP AND BE SURFACE BASED. THIS COULD ALSO BE AN AREA WHERE
LINEAR STRUCTURES COULD BETTER ORGANIZE DUE TO MORE MOIST INFLOW. AT
PRESENT TIME, THIS MORE FAVORABLE ENVIRONMENT APPEARS TOO SPATIALLY
LIMITED FOR AN INCREASE IN WIND/HAIL PROBABILITIES.
..WENDT.. 07/13/2026
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