MESOSCALE PRECIPITATION DISCUSSION 0164
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1131 PM EDT FRI JUL 19 2013
 
AREAS AFFECTED...NERN OH/NWRN PA TO WRN NY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 200252Z - 200700Z
 
SUMMARY...A SHARP THERMAL ZONE IS SLICING THROUGH THE GREAT LAKES
REGION TRIGGERING SEVERAL CONSOLIDATED LINES OF ACTIVE CONVECTIVE
HEAVY RAINFALL WITH SIGNS OF POSSIBLE TRAINING.

DISCUSSION...A SHARP THERMAL ZONE ACTING ON TREMENDOUS UPPER JET
DYNAMICS AND A NARROW BUT VERY ANOMALOUS MOISTURE ZONE IS
TRIGGERING SEVERAL LINES OF ACTIVE CONVECTION AND HEAVY RAINFALL
LATE THIS EVENING. TWO LINE SEGMENTS COMING OFF LAKE ERIE APPEAR
TO HAVE THE MOST POTENTIAL FOR TRAINING OVER THE NEXT SEVERAL
HRS... ESPECIALLY SINCE PARTS OF ERIE/NIAGARA AND ORLEANS IN WRN
NEW YORK STATE HAVE SEEN 2 TO 3.25 INCHES IN THE LAST 3 HRS VIA
MESONET DATA. 02Z ANALYSIS SHOWED A VERY NARROW ZONE OF 2 TO 2.25
INCH PWS WITH STEADY SWRLY/WSWRLY MOIST INFLOW AT 850MB...
FAVORABLE FOR HEAVY RAIN POTENTIAL. ADD IN THAT FROM 03Z TO 09Z
ALL OF THE GLOBAL MODELS FAVOR RIGHT HAND ENTRANCE REGION UPPER
JET DYNAMICS AT 250MB IN THIS VICINITY AND THESE MULTIPLE LINES
COULD PERSIST AND LINGER. 1 HR FFG IS GENERALLY AROUND 2 INCHES OR
GREATER WITH SLIGHTLY LOWER NUMBERS IN NERN OH AND NWRN PA OF 1.5
INCHES... THUS WILL HIGHLIGHT THE ENTIRE REGION FOR LOCALIZED
FLASH FLOODING POTENTIAL.

MUSHER

ATTN...WFO...BGM...BUF...CTP...PBZ...CLE...

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

LAT...LON   41537654 41077829 40447980 40728160 40908250 41368261
            41958175 42637992 42847877 42677595 42167550 41537654