MESOSCALE PRECIPITATION DISCUSSION 0555
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
454 PM EDT MON JUL 24 2017

AREAS AFFECTED...CENTRAL AND NORTHERN NEVADA...S IDAHO...NW UTAH

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

VALID 242052Z - 250252Z

SUMMARY...MULTIPLE SLOW MOVING THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON.  HOURLY RAINFALL RATES ON THE ORDER OF 1 TO 1.5 INCHES
PER HOUR MAY LEAD TO SOME FLOODING PROBLEMS.

DISCUSSION...THE LATEST GOES-16 IS DEPICTING INCREASING CONVECTION
AND COOLING CLOUD TOPS ACROSS CENTRAL SECTIONS OF NEVADA AND ALSO
NEAR THE UTAH/IDAHO BORDER EARLY THIS AFTERNOON. UPPER LEVEL
PARAMETERS, INCLUDING RIGHT ENTRANCE JET DYNAMICS AND A WELL
DEFINED MID-LEVEL TROUGH OVER NORTHERN CALIFORNIA, ARE PROVIDING
AN ENVIRONMENT FAVORABLE FOR LARGE SCALE ASCENT OVER THIS REGION
AND WILL SUPPORT AND MAINTAIN UPDRAFT STRENGTH. PW VALUES NEAR 1
INCH ARE LIKELY THROUGH THE AFTERNOON AND INTO THE EARLY EVENING
BASED ON THE LATEST RAP ANALYSIS, ALONG WITH MLCAPE ON THE ORDER
OF 1000 TO 2000 J/KG.  

THE LATEST HI-RES MODEL GUIDANCE, INCLUDING THE HRRR, APPEAR TO BE
UNDERDONE WITH NEAR TERM RAINFALL AMOUNTS, SUGGESTING ISOLATED ONE
INCH TOTALS.  GIVEN RECENT DOPPLER RADAR TRENDS, THE POTENTIAL
EXISTS FOR ISOLATED 2 INCH AMOUNTS THROUGH 3Z.  PARTS OF THIS
REGION HAD SIGNIFICANT RAINFALL YESTERDAY AND THIS HAS LOCALLY
REDUCED FLASH FLOOD GUIDANCE VALUES. 

HAMRICK

ATTN...WFO...BOI...LKN...PIH...REV...SLC...VEF...

ATTN...RFC...CBRFC...CNRFC...NWRFC...

LAT...LON   42671414 41961327 40801343 39771412 39201507
            38621621 38151746 37921826 38211898 38711966
            39131997 40451977 41821727 42601571