MESOSCALE PRECIPITATION DISCUSSION 0480
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
214 AM EDT THU JUL 13 2017

AREAS AFFECTED...CENTRAL NY STATE

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 130610Z - 130910Z

SUMMARY...CONVECTION DEVELOPING IN THE UPGLIDE NORTH OF A
STATIONARY BOUNDARY WILL TRAIN ACROSS CENTRAL NY STATE EARLY THIS
MORNING...WHICH COULD POSE A FLASH FLOOD THREAT.

DISCUSSION...REGIONAL RADARS ACROSS CENTRAL NY STATE SHOWED
DEVELOPING CONVECTION FORMING NEAR AND JUST NORTH OF A STATIONARY
FRONT BISECTING THE STATE. INSTABILITY (IN THE FORM OF 500-1000
J/KG OF MUCAPE) IN THE UPGLIDE ON THE 305K SURFACE IS FEEDING THE
CONVECTIVE DEVELOPMENT...AND THE LATEST RAP ANALYSIS SHOWED AN
AXIS OF 1.75/2.00 INCH PRECIPITABLE WATER AIR NEARLY COINCIDENT
WITH THE INSTABILITY.

THE 00Z NAM CONUS NEST APPEARED TO HAVE THE BEST HANDLE OF THE
CONVECTION...AND THAT SOLUTION SHOWED THE POTENTIAL FOR LOCAL 2.00
TO 3.00 INCH RAINFALL AMOUNTS ALONG A LINE FROM EAST OF KFZY TO
EAST OF KGFL. PORTIONS OF CENTRAL NY STATE WERE AFFECTED BY
CONVECTION WITH HEAVY RAIN WED...AND ONE HOUR FLASH FLOOD GUIDANCE
VALUES ARE AS LOW AS 1.00 TO 1.50 INCHES IN PORTIONS OF THE
CATSKILLS.

THE ADDITIONAL HEAVY RAINFALL COULD RESULT IN FLASH
FLOODING...ESPECIALLY IN THE PRESENCE OF TRAINING. THE 00Z NAM
CONUS NEST SIMULATED REFLECTIVITY SHOWED THAT THE CONVECTION...AS
IT MOVES EAST TOWARD INTERSTATE 81...SHOULD BEGIN TO OUTRUN ITS
INSTABILITY SOURCE...AND GRADUALLY WEAKEN. THIS SHOULD END THE
FLASH FLOOD THREAT SOMETIME AFTER 09Z.

HAYES/GALLINA

ATTN...WFO...ALY...BGM...BUF...

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

LAT...LON   43677591 43397370 42797364 42777430 42867572
            42967727 43527769