Graphic for MPD #0510

MESOSCALE PRECIPITATION DISCUSSION 0510...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
826 AM EDT WED JUL 19 2017

CORRECTED FOR TYPO IN FIRST PARAGRAPH

AREAS AFFECTED...PORTIONS OF THE DESERT SOUTHWEST

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

VALID 191220Z - 191529Z

SUMMARY...A PAIR OF MCVs ARE INTERACTING WITH AVAILABLE MOISTURE
AND INSTABILITY TO GENERATE NEW CONVECTION.  HOURLY RAIN RATES UP
TO 1.5" WITH LOCAL AMOUNTS TO 2.5" ARE EXPECTED.

DISCUSSION...A PAIR OF MCVs GENERATED BY CONVECTIVE ACTIVITY ON
TUESDAY ARE INTERACTING WITH PRECIPITABLE WATER VALUES OF 1.5-2". 
INFLOW AT 850 HPA IS SOUTHERLY, WHICH IS IMPORTING MU CAPE VALUES
OF 1000-2000 J/KG FROM SOUTHEAST CA/SOUTHWEST AZ INTO THE MORE
NORTHERN MCV OVER NORTHWEST AZ.  THE ATMOSPHERE ACROSS THE REGION
IS LIKELY SATURATED.  NEW CONVECTIVE ACTIVITY IS SHOWING COOLING
CLOUD TOPS AND A BIT OF LIGHTNING ACROSS SOUTHEAST CA, NORTHWEST
AZ, AND SOUTHERN NV.  EFFECTIVE BULK SHEAR OF ~25 KTS COULD ACT TO
ORGANIZE THE ACTIVITY INTO SHORT BANDS AROUND THE MCVs.

THE MESOSCALE GUIDANCE HAS A SIGNAL FOR LOCAL AMOUNTS UP TO 2.5"
HERE OVER THE NEXT SEVERAL HOURS, WITH THE HIGHEST RISK THROUGH
15Z.  HOURLY RAIN RATES UP TO 1.5" ARE EXPECTED NEAR THE MCVs AS
THE CONVECTION MOVES WEST WITH THE CIRCULATIONS AT ROUGHLY 10 KTS.

ROTH

ATTN...WFO...FGZ...PSR...SGX...VEF...

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

LAT...LON   36951514 36621373 34781318 32981440 32661564
            33351665 35381625


Last Updated: 826 AM EDT WED JUL 19 2017