Graphic for MPD #0500

MESOSCALE PRECIPITATION DISCUSSION 0500
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
823 PM EDT MON JUL 17 2017

AREAS AFFECTED...CNTRL TO SRN AZ

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

VALID 180022Z - 180600Z

SUMMARY...SCATTERED THUNDERSTORMS CAPABLE OF 2+ IN/HR RAINFALL
RATES WILL CONTINUE TO IMPACT PORTIONS OF CNTRL TO SRN AZ THROUGH
05Z POSING A CONTINUED RISK OF FLASH FLOODING.

DISCUSSION...REFLECTIVITY FROM KIWA AND KEMX SHOWED WIDELY
SCATTERED THUNDERSTORMS OVER S-CNTRL AND SERN AZ AS OF 00Z. GPS
DATA CONTINUES TO SHOW PRECIPITABLE WATER VALUES RANGING FROM 1.7
TO 2.0 INCHES ACROSS SRN AZ...WHICH CORRELATES TO STANDARDIZED
ANOMALIES OF +2 TO +3. THIS ENVIRONMENT LED TO A 1 HOUR OBSERVED
RAINFALL RATE NEAR 2.5 INCHES WEST OF TUS NEAR 21Z. MLCAPE VALUES
OF 1000-2000 REMAIN ACROSS S-CNTRL AZ PER 23Z DATA FROM THE SPC
MESOANALYSIS PAGE AND 00Z RAOB FROM TUS...WITH LOWER VALUES AT OR
ABOUT 500 J/KG CLOSER TO THE SRN AZ/NM BORDER. LFC TO EL MEAN
WINDS ARE GENERALLY WEAK AT 10 KT OR LESS...CONTRIBUTING TO SLOW
STORM MOTIONS BUT RELATIVELY ENHANCED ELY 700 MB FLOW OF 10-15 KT
IS IN PLACE ACROSS SRN AZ TO THE NORTH OF AN MCV OVER SWRN AZ AND
WEAK LOW SOUTH OF SERN AZ PER VAD WIND PLOTS AND RAP ANALYSES.

RAP FORECASTS OVER THE NEXT FEW HOURS SHOW THE 700 MB FLOW REMAINS
IN INTENSITY OR STRENGTHENS SLIGHTLY BY ANOTHER 5 KT THROUGH 06Z
WHICH MAY AID IN BRIEF TRAINING AND REPEATING MOTIONS OF HEAVY
RAIN CORES. NO MODEL HAS BEEN HANDLING CONVECTIVE TRENDS OR
PLACEMENT WELL ACROSS THE SOUTHWEST TODAY...BUT THERE ARE HINTS IN
SOME OF THE OPERATIONAL AND EXPERIMENTAL HI-RES GUIDANCE TO
SUGGEST ONGOING SHOWER ACTIVITY OVER WRN NM MAY SURVIVE AND
REINTENSIFY OVER ERN AZ BY 06Z. WHILE COVERAGE IS UNCERTAIN...IT
APPEARS THE FLASH FLOOD THREAT WILL LINGER AT LEAST ANOTHER 4-6
HOURS OVER PORTIONS OF CNTRL TO SRN AZ.

OTTO

ATTN...WFO...FGZ...PSR...TWC...

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

LAT...LON   34330993 33790905 31980946 31131102 31931341
            33141330 34131220


Last Updated: 823 PM EDT MON JUL 17 2017