128  
ACUS11 KWNS 141816  
SWOMCD  
SPC MCD 141815  
MEZ000-NHZ000-VTZ000-142015-  
 
MESOSCALE DISCUSSION 1613  
NWS STORM PREDICTION CENTER NORMAN OK  
0115 PM CDT TUE JUL 14 2026  
 
AREAS AFFECTED...PARTS OF WESTERN MAINE...NORTHERN NEW HAMPSHIRE  
AND VERMONT  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 141815Z - 142015Z  
 
PROBABILITY OF WATCH ISSUANCE...60 PERCENT  
 
SUMMARY...SEVERE THUNDERSTORM DEVELOPMENT APPEARS INCREASINGLY  
PROBABLE ACROSS THE ST. LAWRENCE VALLEY THROUGH THE WESTERN NEW  
ENGLAND INTERNATIONAL BORDER VICINITY BY 4-6 PM EDT. THESE MAY BE  
ACCOMPANIED BY LARGE HAIL AND POTENTIAL TO PRODUCE TORNADOES, IN  
ADDITION TO DAMAGING WIND GUSTS.  
 
DISCUSSION...A MESOSCALE CONVECTIVE VORTEX HAS PROGRESSED ACROSS THE  
INTERNATIONAL BORDER AND WILL CONTINUE EAST-SOUTH EAST OF THE  
GREENVILLE ME VICINITY TOWARD DOWNEAST COASTAL AREAS THIS AFTERNOON.  
THUNDERSTORM ACTIVITY NEAR THE VORTEX HAS BEEN STEADILY  
DISSIPATING FOR SEVERAL HOURS NOW, BUT RENEWED THUNDERSTORM  
DEVELOPMENT PERSISTS ALONG (AND TO THE COOL SIDE OF) AN ASSOCIATED  
OUTFLOW BOUNDARY TRAILING WEST-NORTHWESTWARD ACROSS SOUTHWESTERN  
QUEBEC.  
 
SOME OF THIS UPSTREAM ACTIVITY HAS SHOWN RECENT SIGNS OF  
INTENSIFICATION, MAINLY NEAR AND TO THE WEST OF THE ST. LAWRENCE  
VALLEY, WHERE INFLOW MAY BE EMANATING FROM A MOIST BOUNDARY-LAYER  
WITH SURFACE DEW POINTS NEAR 70F. STILL MOSTLY BENEATH A PLUME OF  
WARM AND CAPPING ELEVATED MIXED-LAYER AIR, THIS AIR APPEARS  
CHARACTERIZED BY CAPE IN EXCESS OF 2000 J/KG.  
 
THROUGH 20-22Z, MODEL OUTPUT SUGGESTS THAT THE ELEVATED MIXED-LAYER  
PLUME WILL SLOWLY BECOME SUPPRESSED SOUTHWARD ACROSS SOUTHERN QUEBEC  
THROUGH THE INTERNATIONAL BORDER VICINITY. AS IT DOES, THERE  
APPEARS INCREASING POTENTIAL FOR SCATTERED THUNDERSTORMS TO CONTINUE  
INTENSIFYING ALONG AND, PERHAPS, ACROSS THE OUTFLOW BOUNDARY,  
BECOMING INCREASINGLY ROOTED IN THE UNSTABLE BOUNDARY-LAYER. IN THE  
PRESENCE OF STRONG DEEP-LAYER SHEAR, A FEW SUPERCELL STRUCTURES MAY  
EVOLVE, ACCOMPANIED BY A RISK FOR LARGE HAIL, DAMAGING WIND GUSTS  
AND POTENTIAL FOR A TORNADO OR TWO WHILE SPREADING INTO AND ACROSS  
THE INTERNATIONAL BORDER VICINITY.  
 
..KERR/HART.. 07/14/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...CAR...GYX...BTV...  
 
LAT...LON 46007068 45476945 44846913 44367070 45877459 47037437  
47087288 46007068  
 
MOST PROBABLE PEAK TORNADO INTENSITY...120-145 MPH  
MOST PROBABLE PEAK WIND GUST...65-80 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN  
 
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