MESOSCALE PRECIPITATION DISCUSSION 0491
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
244 PM EDT MON JUL 25 2016
 
AREAS AFFECTED...NORTHERN PA...THE SOUTHERN TIER OF NY STATE 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 251840Z - 252240Z
 
SUMMARY...TRAINING CONVECTION ALONG A LOW LEVEL MOISTURE AXIS
COULD PRESENT A SHORT TERM FLASH FLOOD THREAT THIS AFTERNOON,

DISCUSSION...CONVECTION HAS BECOME WEST TO EAST ORIENTED ACROSS
PORTIONS OF NORTHERN PA AND CENTRAL NY STATE THIS AFTERNOON. THE
CONVECTION IS TRACKING ALONG THE LEADING EDGE OF A 2.10 INCH
PRECIPITABLE WATER AXIS EXTENDING ACROSS WESTERN NY STATE/WESTERN
PA. CLEARING BEHIND CONVECTION EARLIER HAS ALLOWED THE INSTABILITY
TO REBOUND...WITH 1000-2000 J/KG MLCAPE. COOLING TEMPERATURES ON
THE IR LOOP SUGGEST THAT THE CONVECTION IS GETTING BETTER
ORGANIZED. 

WHILE MUCH OF THE CONVECTION IS OUTFLOW DOMINATED...THE KBUF RADAR
INDICATED HOURLY RAINFALL RATES BETWEEN 1.50 AND 1.75 INCHES.
GIVEN THE DEEP OF THE WARM CLOUD LAYER...AND THE KDP SIGNATURE ON
THE KBUF RADAR...HAIL DOES NOT SEEM TO BE A SIGNIFICANT
CONTAMINANT TO THE RADAR ESTIMATES. THESE RADAR ESTIMATES...
COMBINED WITH THE ORIENTATION OF THE CONVECTION...SUGGESTS THAT
SHORT TERM TRAINING COULD RESULT IN A FLASH FLOOD THREAT THROUGH
THE AFTERNOON HOURS.

MOST OF THE HIGH RESOLUTION GUIDANCE SUGGEST THE POTENTIAL FOR
LOCAL 2-3 INCH RAINFALL AMOUNTS WITH THE CONVECTION OVER NORTHERN
PA/CENTRAL NY STATE. GIVEN THE KBUF RADAR ESTIMATES...THESE VALUES
LOOK ATTAINABLE. IT HAS BEEN FAIRLY DRY ACROSS THIS REGION
LATELY...AND ONE HOUR FLASH FLOOD GUIDANCE ARE GENERALLY BETWEEN
2.00 AND 3.00 INCHES. THUS...THE FLASH FLOOD THREAT WOULD BE
DEPENDENT ON TRAINING...SO AT THIS POINT FLASH FLOODING IS JUST
CONSIDERED POSSIBLE.

HAYES

ATTN...WFO...ALY...BGM...BUF...CTP...OKX...

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

LAT...LON   42557616 42537540 42487449 42237380 41567387 
            41357423 41487573 41527709 41577769 41547775 
            41817921 42397844 42397839