MESOSCALE PRECIPITATION DISCUSSION 0368
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
654 PM EDT SUN JUL 19 2015
 
AREAS AFFECTED...NORTHERN VT...NORTHERN AND CENTRAL NH...WESTERN
ME 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 192253Z - 200453Z
 
SUMMARY...PERSISTENT MOIST SOUTHERLY INFLOW MAY SUPPORT ADDITIONAL
LOCALLY HEAVY RAINS AND FLASH FLOODING.

DISCUSSION...LATEST SURFACE OBSERVATIONS CONTINUE TO INDICATE AN
OUTFLOW BOUNDARY/DIFFERENTIAL HEATING ZONE TO THE SOUTH OF A SLOW
MOVING FRONTAL BOUNDARY AND ONGOING CONVECTION OVER NORTHERN NEW
ENGLAND.  SPC MESOANALYSIS SHOWS PWS 1.8-2 INCHES ACROSS THIS
REGION WITH WEST-SOUTHWESTERLY 850 MB WINDS OF 20-30 KTS AND
MUCAPE VALUES OF 1000-2000 J/KG.  DURING THE EVENING
HOURS...BACKING WINDS AHEAD OF A SHORTWAVE TROUGH APPROACHING FROM
THE GREAT LAKES WILL CONTINUE TO TAP MOIST AND UNSTABLE AIR FROM
THE SOUTH...DRAWING IT INTO THIS REGION OF ENHANCED LOW LEVEL
CONVERGENCE...SUPPORTING REDEVELOPING CONVECTION FROM THE WEST. 
THE 21Z HRRR AND 12Z HRW-ARW/NMMB AGREE ON ADDITIONAL LOCAL
RAINFALL AMOUNTS OF 2-3 INCHES BY 05Z.  THESE AMOUNTS MAY POSE
FLASH-FLOODING CONCERNS...ESPECIALLY ACROSS PORTIONS OF NORTHERN
VT AND NH...WHERE THE LATEST 3-HR FLASH FLOOD GUIDANCE VALUES WERE
UNDER 2-INCHES.

PEREIRA

ATTN...WFO...BTV...GYX...

ATTN...RFC...NERFC...

LAT...LON   45187302 45107247 44877174 44637113 44157037 
            43766995 43497029 43537110 43717179 44457312 
            44987342