MESOSCALE PRECIPITATION DISCUSSION 0537
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
335 PM EDT WED AUG 10 2016
 
AREAS AFFECTED...SOUTHERN UT...NORTHWEST AND CENTRAL AZ 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 101934Z - 110030Z
 
SUMMARY...STRONG FORCING AND INSTABILITY WITH MODERATE MOISTURE TO
PRODUCE SCATTERED CONVECTION WITH RAIN RATES CAPABLE OF PRODUCING
AT LEAST ISOLATED FLASH FLOODING CONCERNS. 

DISCUSSION...WV LOOP DENOTES SHEARING SHORTWAVE VORTICITY CENTER
IN FAR SE CA SHIFTING EWARD PROVIDING MODERATE DPVA/HEIGHT FALLS. 
THIS ALONG WITH EXCELLENT RIGHT ENTRANCE ASCENT FROM 70KT JET
ACROSS UT ALLOWS FOR MAINTAINED SUPPORT OF DEVELOPED UPDRAFTS. 
18Z FGZ SOUNDING INDICATES MODEST MOISTURE AVAILABILITY SUB 600MB
WITH WARM CLOUD PROCESS RAINFALL GENERATION...S AND SSELY FLOW
ACROSS CENTRAL AZ BECOMES IS GENERALLY CONVERGENT AS IT VEERS
ACROSS THE MOGOLLON RIM PROVIDING CONTINUED LOW LEVEL FORCING  (AS
WELL A 7H 25-30 KT SWLY FLOW) FOR THE POTENTIAL FOR UPSTREAM
REDEVELOPMENT AS THE BEST FORCING ALOFT SHIFTS NORTH TO SOUTH
THROUGH THE EARLY EVENING.  WITH SFC-7H FLOW PROVIDING MODERATE
MOISTURE FLUX FROM A RICHER SOURCE REGION WITH TPWS OVER 1.5"
SOUTHWEST OF THE RIM... BUT VALUES NEAR OR ABOVE NORMAL NORTH OF
THE RIM.  RAINFALL EFFICIENCY AND RATES MAY BE LARGE ENOUGH
(1.25-1.5"/HR) TO SUPPORT SOME FLASH FLOODING
CONCERNS...PARTICULARLY ACROSS SW FACING SLOT CANYONS AND TERRAIN
ACROSS S UT.  GIVEN DEEPER FLOW WITH SOME SLOWING DUE TO SUPERCELL
MODE (SEE SPC MCD 1510 FOR MORE DETAILS) AS WELL AS THE SOUTHWARD
SINKING BEST FORCING SOME POTENTIAL FOR UPSTREAM DEVELOPMENT IS
LIKELY...WHICH MAY POSE SOM CROSS TRACK/REPEATING IS POSSIBLE AS
WELL...PARTICULARLY GIVEN THE UNIDIRECTIONAL FLOW THROUGH THE BULK
OF THE CLOUD BEARING LAYER.   SOME LIMITING CONCERNS IS THE
OVERALL COVERAGE OF THE CONVECTION...BUT THE RIGHT PLACE/RIGHT
ORIENTATION TO TERRAIN ALONG WITH THE STRONG FORCING/VIGOROUS
UPDRAFT STRENGTH STILL POSES THE CONCERN FOR FLASH FLOODING TO
OCCUR.  

GALLINA

ATTN...WFO...FGZ...PSR...SLC...VEF...

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

LAT...LON   38711202 38121096 37271123 35991133 34531015 
            33751060 34381259 35691387 37151383 38091314