MESOSCALE PRECIPITATION DISCUSSION 0321
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
216 PM EDT TUE AUG 26 2014
 
AREAS AFFECTED...SRN UT...NWRN AZ 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 261815Z - 262215Z
 
SUMMARY...CONVECTION SHOULD CONTINUE TO EXPAND ACROSS THE OUTLINED
AREA THROUGH THE AFTERNOON HOURS AS UPPER-LEVEL LOW/TROUGH AXIS
MOVES SLOWLY EASTWARD. RESPECTABLE MOISTURE AND INSTABILITY AXIS
ACROSS THESE AREAS MAY LEAD TO RAINFALL RATES APPROACHING 1
INCH/HR.

DISCUSSION...MIXED LAYER CAPE VALUES OF 1000 TO 2000 J/KG...AS
INDICATED BY SPC MESOANALYSIS AND SATELLITE DATA...ARE ADVECTING
INTO THE OUTLINED AREA ON 10-20 KT LOW-LEVEL SOUTHERLY FLOW.
CONVECTION HAS ALREADY BEGUN TO INCREASE ACROSS NWRN AZ BY MIDDAY
ALONG THIS MOISTURE/INSTABILITY AXIS. PWAT VALUES IN THE 1.0 TO
1.5 INCH RANGE PER SPC MESOANALYSIS ARE NOT TERRIBLY ANOMALOUS --
BUT UPPER-LEVEL FORCING IS COMPENSATING FOR THE MARGINAL MOISTURE
AS THE SHORTWAVE APPROACHES.

THE ATMOSPHERE IS EXPECTED TO BECOME MORE FAVORABLE FOR CONVECTION
THROUGH THE AFTERNOON AS UPPER-LEVEL FLOW BECOMES MORE DIFFLUENT
AND THE OUTLINED AREA BECOMES SITUATED IN THE RIGHT ENTRANCE
REGION OF 70-80 KT 250 HPA JET STREAK. HI-RES MODELS INDICATE THAT
SOME AREAS MAY RECEIVE A COUPLE INCHES OF RAIN THROUGH LATE
AFTERNOON. RAINFALL RATES MAY APPROACH 1 INCH/HR AT TIMES...WHICH
COULD LEAD TO ISOLATED INSTANCES OF FLASH FLOODING.

RYAN

ATTN...WFO...ABQ...GJT...FGZ...SLC...VEF...

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

LAT...LON   37740948 36171030 34661205 34531347 35151391 36651327
            37671231 38791077 38600971 37740948