MESOSCALE PRECIPITATION DISCUSSION 0494
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
421 PM EDT TUE SEP 15 2015
 
AREAS AFFECTED......NORTHERN AND CENTRAL UT... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 152025Z - 160030Z
 
SUMMARY...TRAINING CONVECTIVE CELLS IN A RELATIVELY MOIST AIRMASS
COULD RESULT IN LOCAL FLASH FLOODING THROUGH THE LATE AFTERNOON
HOURS. LOCAL 1.50 INCH RAINFALL AMOUNTS ARE POSSIBLE IN AREAS
WHERE TRAINING OCCURS.

DISCUSSION...CONVECTION FIRING WITHIN A POOL OF 500 TO 1000 J/KG
INSTABILITY CONTINUES TO TRACK SLOWLY EAST ACROSS PORTIONS OF
NORTH CENTRAL UT. THE CONVECTION ALSO SITS IN A POOL OF 1.00 INCH
PRECIPITABLE WATER AIR... WHICH IS RESULTING IN HOURLY RAINFALL
RATES OF 0.50 TO 1.00 INCHES (BASED ON MESOWEST OBSERVATIONS AND
KMTX RADAR ESTIMATES). THE MAIN AREA OF CONVECTION HAS BEEN
PROGRESSIVE THUS FAR THIS AFTERNOON...AND SOUTHWESTERLY CORFIDI
VECTORS SUGGEST THIS WILL CONTINUE. 

ADDITIONAL CONVECTION IS BEGIN TO DEVELOP OVER THE NORTHERN AND
CENTRAL WASATCH MOUNTAINS. THE LATEST HRRR SUGGESTS THAT
INSTABILITY FEEDS INTO THE HIGHER TERRAIN OF UT THROUGH LATE
AFTERNOON...SUSTAINING ADDITIONAL CONVECTION. MID LEVEL WINDS
INDICATE THAT THE ADDITIONAL ACTIVITY COULD TRAIN ACROSS AREAS
THAT ARE RECEIVING HEAVY RAIN.

MUCH OF THE HIGH RESOLUTION GUIDANCE (INCLUDING THE 18Z HRRR AND
12Z NSSL WRF/12Z WRF ARW) SHOWED LOCATION 1.50 INCH RAINFALL
AMOUNTS ACROSS THE NORTHERN AND CENTRAL WASATCH THROUGH 00Z. THESE
AMOUNTS COULD BE REALIZED IF TRAINING OCCURS THROUGH LATE
AFTERNOON. 

HAYES

ATTN...WFO...SLC...

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

LAT...LON   41391133 40841032 40761024 40081028 39461083 
            39121146 38841256 39221273 40371217 41091175