MESOSCALE PRECIPITATION DISCUSSION 0226
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
857 AM EDT MON JUL 28 2014
 
AREAS AFFECTED...CENTRAL AND NORTHERN NY & CENTRAL NEW ENGLAND 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 281256Z - 281856Z
 
SUMMARY...LOW-TOPPED CONVECTION CONTINUES TO CONCENTRATE ACROSS
PORTIONS OF WESTERN NY THIS MORNING.  WITH INCREASING INSTABILITY
EXPECTED THROUGH THE DAY TODAY, FLASH FLOODING IS CONSIDERED
POSSIBLE ACROSS THE REGION.

DISCUSSION...A DEEP CYCLONE IS TRACKING EASTWARD ACROSS WESTERN NY
THIS MORNING.  AHEAD OF THE SYSTEM, INFLOW AT 850 HPA IS
INCREASING INTO CENTRAL AND WESTERN NEW ENGLAND, AND LOW-TOPPED
CONVECTION HAS BEEN SLOW-MOVING BETWEEN BUFFALO AND SYRACUSE.  THE
MOST RECENT SPC MESOANALYSIS INDICATES SOME INCREASE IN CAPES IN
THE REGION, WITH A BUBBLE OF 1000+ J/KG ACROSS SOUTH-CENTRAL NY. 
PRECIPITABLE WATER VALUES ARE IN THE 1.25-1.50" RANGE, ON THE LOW
END FOR REGIONAL FLASH FLOODING.

AS 850 HPA INFLOW INCREASES AND AREAS OF SOUTHERN NY AND SOUTHERN
NEW ENGLAND RECEIVE INSOLATION WHICH SHOULD INCREASE CAPE VALUES
DURING THE DAY TODAY, THE ENVIRONMENT SHOULD BE MORE CONDUCIVE FOR
THE WET MULTI-CELL ENVIRONMENT, PARTICULARLY ACROSS CENTRAL NEW
ENGLAND.  SOME COMMA HEAD ACTIVITY COULD CONTINUE A THREAT ACROSS
WESTERN NY, PER COORDINATION WITH NESDIS/SAB.  THE MOST RECENT RAP
RUNS WERE DOING A BETTER JOB WITH CAPE VALUES THAN THE 00Z ARW, SO
UTILIZED THESE AS A GUIDE.  THE 00Z SSEO MEAN NEIGHBORHOOD
PROBABILITIES OF REACHING THREE HOUR FLASH FLOOD GUIDANCE SHOW
MAXIMA OF 30-50% DURING THE NEXT SEVERAL HOURS NEAR VT AND NH,
WHERE THE MESOSCALE GUIDANCE SHOWS A MODERATE SIGNAL FOR EXCESSIVE
RAINFALL.  HOURLY RAINFALL RATES UP TO 1.5" COULD LEAD TO REGIONAL
FLASH FLOODING.

ROTH

ATTN...WFO...GYX...BOX...BTV...ALY...BGM...BUF...

ATTN...RFC...MARFC...NERFC...OHRFC...

LAT...LON   42457079 42237333 42257782 42467906 43217908 43427838
            43347711 43457675 43667631 44217639 44867533 45057478
            45057279 45097211 45397077 44747019 44177004 43307047
            42457079