MESOSCALE PRECIPITATION DISCUSSION 0441
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
219 PM EDT TUE AUG 11 2015
 
AREAS AFFECTED...FAR SOUTHERN UT/NORTHERN TO CENTRAL AZ... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 111819Z - 112234Z
 
SUMMARY...A MID/UPPER LEVEL DISTURBANCE LIFTING OUT OF
SOUTHEASTERN AZ HAS BEGUN TO TRIGGER WIDESPREAD CONVECTION ACROSS
CENTRAL/NORTHERN SECTIONS OF THE STATE. WHILE THE CURRENT ACTIVITY
HAS GENERALLY BE DROPPING 0.25 TO 0.50 INCH HOURLY RATES...EXPECT
THESE TO COME UP AS THE ATMOSPHERE CONTINUES TO DESTABILIZE GIVEN
SUFFICIENT DIURNAL HEATING. FLASH FLOODING IS
POSSIBLE...PARTICULARLY IN REGIONS OF COMPLEX TERRAIN.

DISCUSSION...ENHANCED MONSOONAL MOISTURE BEING PUMPED NORTHWARD
ACROSS THE WESTERN PERIPHERY OF THE SOUTHERN PLAINS ANTICYCLONE
HAS BROUGHT 1.90 INCH PWATS UP TO THE PHOENIX AZ METRO AREA. A
MULTI-HOUR LOOP OF THE BLENDED-TPW PRODUCT SHOWS MOISTURE ON THE
INCREASE ACROSS NORTHERN SECTIONS OF AZ AS WELL. THIS AIR MASS
CONTINUES TO DESTABILIZE IN THE PRESENCE OF 0-3 KM LAPSE RATES OF
8 TO 9 C/KM. HOWEVER...WEAKER MID-LEVEL LAPSE RATES HAVE TEMPERED
THE VERTICAL EXTENT OF CONVECTIVE TOWERS WITH TOPS GENERALLY
AROUND -55 TO -60C. GIVEN CONTINUED DIURNAL HEATING...EXPECT TOPS
TO FURTHER COOL AS ANY RESIDUAL INHIBITION IS ERODED IN THE COLUMN.

IT SEEMS LIKELY THE LOWER END HOURLY RAINFALL RATES SHOULD COME UP
GIVEN THE MOIST TROPOSPHERIC PROFILES AND INCREASING INSTABILITY.
RECENT CAMS SUPPORT RATES IN THE 0.50 TO 1 INCH
RANGE...PARTICULARLY THE PAST FEW CYCLES OF THE HRRR. THERE IS A
MULTI-MODEL AGREEMENT IN THE HEAVIEST AMOUNTS IN THE 1 TO 2 INCH
RANGE ACROSS NORTHERN AZ THROUGH 00Z. FOR MORE INFORMATION ON THIS
SYSTEM...PLEASE CHECK OUT THE LATEST SPE FROM NESDIS/SAB. 


RUBIN-OSTER

ATTN...WFO...FGZ...GJT...PSR...SLC...TWC...VEF...

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

LAT...LON   37461305 37421098 36731022 35721111 33181091 
            33071243 34971373 36671412