Graphic for MPD #0300
MESOSCALE PRECIPITATION DISCUSSION 0300
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
434 PM EDT MON JUN 05 2017

AREAS AFFECTED...NORTHERN PA...SOUTHERN NY

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

VALID 052035Z - 060100Z

SUMMARY...SCATTERED CONVECTION POTENTIAL CONSOLIDATE INTO A
BACKBUILDING ENVIRONMENT FOR SOME INCREASED FLOODING CONCERNS.

DISCUSSION...GOES-E WV LOOP DENOTES AN INCREASINGLY SHEARED
SHORTWAVE LIFTING OUT OF N NY EXTENDING BACK TO NW PA PROVIDING
BROAD SCALE ASCENT AND A WEAK SURFACE LOW OVER CENTRAL NY.  A COLD
FRONT DRAPES BACK TO THE SOUTHWEST ENHANCED BY LAKE BREEZE.  IN
THE WARM SECTOR INSTABILITY IS SUFFICIENT WITH ELONGATED BAND OF
500-750 J/KG MLCAPE THOUGH SBCAPES ARE SLIGHTLY HIGHER TOWARD 1500
J/KG UPSTREAM IN THE SOURCE REGION OVER N PA.  MOISTURE IS
SUFFICIENT WITH TDS IN THE LOWER TO MID 60S HELPS TO RAISE A
LOCALIZED POOL OF TPW SLIGHTLY OVER 1.25".  AT THIS POINT FAIRLY
CONFLUENT LOW LEVEL FLOW (FROM SE NEAR HUDSON VALLEY AND SW FROM N
PA) PROVIDES EFFECTIVE ASCENT FOR CONVECTIVE DEVELOPMENT AND
MODERATE MST FLUX TO ALLOW FOR RAIN RATES UP TO 1.5"/HR. AT THIS
POINT CELLS ARE MORE OR LESS INDIVIDUAL AND SCATTERED AND
ADVANCING EASTWARD WITH SOME RANDOM ACCIDENTAL REPEAT TRACKS
POSSIBLE.  OVERALL LOWER FFG/GROUND CONDITIONS ARE A BIT LOW TO
ALLOW FOR SOME CELLS TO EXCEED AND LEAD TO LOCALIZED FF
CONDITIONS. 

OVERALL PATTERN WILL BECOME MORE CONDUCIVE OF A LARGER
SCALE/UPSCALE GROWTH POTENTIAL. GOES WV/GLOBAL FORECAST MODELS ALL
POINT TO THE CURRENT SHORTWAVE TO WEAKEN IN FAVOR OF THE
LARGER/COMPACT SHORTWAVE RETROGRADING SW...THIS WILL ALLOW FOR
INCREASED DIFFLUENCE ALOFT AND WITH EXPANDING RIGHT ENTRANCE JET
DYNAMICS TO MAINTAIN STRONG ASCENT THROUGH LATE
EVENING...PARTICULARLY NEAR THE N POCONOS AND W CATSKILLS.  THIS
ORIENTATION WILL LIKELY ALSO SUPPORT BACKBUILDING/UPSTREAM
DEVELOPMENT.  LIMITING FACTOR IS LIKELY TO BE INSTABILITY GIVEN
THE SOURCE REGION WILL BE UPSTREAM ACROSS PA (WHICH IS CURRENTLY
CLOUD COVERED DUE TO JET AXIS)...POTENTIALLY FURTHER SUPPORTING
BACKWARD PROPAGATING C-VECTORS TOWARD 00Z. WITH SLOW COMPLEX
MOTIONS EVEN WITH REDUCED INSTABILITY/STRATIFORM RAINS TOWARD THE
NE...THE POTENTIAL FOR RAINFALL TOTALS OF 2-3" ARE POSSIBLE
KEEPING FF THREAT GOING.

GALLINA

ATTN...WFO...ALY...BGM...CTP...OKX...PHI...

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

LAT...LON   42907466 42767383 41987356 41397476 41117553
            41467760 42327714 42807603


Last Updated: 434 PM EDT MON JUN 05 2017