MESOSCALE PRECIPITATION DISCUSSION 0409
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1229 AM EDT SAT JUL 02 2016
 
AREAS AFFECTED...SRN NV INTO NWRN AZ 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 020428Z - 021000Z
 
SUMMARY...CLUSTERS OF STORMS OVER SRN NEVADA WILL CONTINUE TO
STEADILY PROGRESS TOWARD THE SSE...LIKELY REACHING PORTIONS OF
NWRN ARIZONA IN THE NEXT 2-3 HOURS. HOURLY RATES OF 1-1.5 IN/HR
WILL LIKELY CONTINUE TO POSE A FLASH FLOOD THREAT.

DISCUSSION...RADAR AND SATELLITE TRENDS SHOWED A COMPLEX OF
THUNDERSTORMS OVER SRN NEVADA DROPPING SSE AT AROUND 20 KTS AT
04Z...INTO LOW LEVEL INFLOW OF ABOUT 15 TO 25 KTS PER VAD WIND
PROFILE AT KESX. THE 00Z RAOB FROM VEF INDICATED ROUGHLY 2000 J/KG
OF CAPE WITH PRECIPITABLE WATER OF 1.12 INCHES...STILL QUITE
ANOMALOUS FOR EARLY JULY. THIS COMPLEX IS BEING AIDED BY DIFFLUENT
FLOW ALOFT JSUT AHEAD OF AN UPPER TROUGH AXIS LOCATED ALONG THE
SIERRA NEVADA RANGE AT 04Z.

RECENT RAP AND SPC MESOANALYSES INDICATE HIGHER INSTABILITY OF
1500 TO 2000+ J/KG OVER SRN NEVADA INTO THE SWRN QUADRANT OF
ARIZONA...WHILE LOWER VALUES WERE PRESENT TO THE NORTH. IT IS
EXPECTED THAT THE ONGOING CLUSTERS OF CONVECTION OVER SRN
NEVADA...WITH RAINFALL RATES OF 1 TO 1.5 IN/HR...WILL CONTINUE TO
FOLLOW SEWD ALONG THE INSTABILITY GRADIENT OVER THE NEXT 3-4
HOURS. FLASH FLOODING WILL BE POSSIBLE WITHIN HEAVIER RAINFALL
RATES ALONG THE LEADING EDGE OF THE COMPLEX THROUGH
08-10Z...ALTHOUGH THE LEADING EDGE OF CONVECTION IS EXPECTED TO
REMAIN SOMEWHAT PROGRESSIVE TOWARD THE SSE. POSSIBLE WEAKENING OF
THESE STORMS IS EXPECTED BEYOND 10Z AS UPPER SUPPORT
WEAKENS...INDICATED BY RECENT RUNS OF THE PARALLEL HRRR WHICH HAS
LIKELY BEEN HANDLING THE ONGOING SITUATION THE BEST.

OTTO

ATTN...WFO...FGZ...VEF...

ATTN...RFC...CBRFC...CNRFC...

LAT...LON   37421605 37351482 36961408 36351320 35801269 
            35411261 35001292 34671372 35001498 35991652 
            36481715 36791723 37101708 37281676