MESOSCALE PRECIPITATION DISCUSSION 0527
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
728 PM EDT FRI JUL 21 2017

AREAS AFFECTED...WESTERN CO...CENTRAL/EASTERN UT

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

VALID 212325Z - 220425Z

SUMMARY...SCATTERED AREAS OF SLOW-MOVING SHOWERS AND THUNDERSTORMS
WILL CONTINUE OVER THE NEXT SEVERAL HOURS WITH ADDITIONAL CONCERNS
FOR FLASH FLOODING. CONDITIONS SHOULD IMPROVE BY LATE EVENING.

DISCUSSION...MONSOON-DRIVEN SHOWERS AND THUNDERSTORMS CONTINUE
ACROSS A LARGE AREA OF CENTRAL/WESTERN CO AND INTO CENTRAL/EASTERN
UT AS A RATHER DEEP COLUMN OF MOISTURE PERSISTS AND COUPLES WITH
ROBUST DIURNAL HEATING AND OROGRAPHICS FOR RATHER WIDESPREAD
CONVECTIVE DEVELOPMENT.

THE LATEST CIRA-LPW DATA AND GOES-15 SOUNDER DATA CONTINUE TO SHOW
PWATS LOCALLY EXCEEDING 1 INCH...WHICH IS FOSTERING PWAT ANOMALIES
AS HIGH AS 2 STANDARD DEVIATIONS ABOVE NORMAL. THIS WILL CONTINUE
TO FAVOR HIGHLY EFFICIENT RAINFALL PROCESSES FOR ENHANCED RAINFALL
RATES AND ESPECIALLY WHEN COMBINED WITH SOME OF THE OROGRAPHIC
FORCING OVER THE HIGHER TERRAIN.

THE LATEST HRRR GUIDANCE ACTUALLY SUGGESTS A FAIR AMOUNT OF
CONVECTION PERSISTING OVER ESPECIALLY EASTERN UT AND WESTERN CO
GOING THROUGH ABOUT 03Z...WITH A WEAKENING TREND THEREAFTER AS
INSTABILITY ACROSS THE REGION BECOMES EXHAUSTED.

EXPECT ADDITIONAL RAINFALL AMOUNTS OF AS MUCH AS 1 TO 2
INCHES..WITH ISOLATED AMOUNTS UP TO 3 INCHES WITHIN SOME OF THE
STRONGER CONVECTIVE CORES AND NEAR FAVORED UPSLOPE AREAS. THIS
WILL MAINTAIN THE THREAT FOR FLASH FLOODING.

ORRISON

ATTN...WFO...GJT...PUB...RIW...SLC...

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

LAT...LON   41030911 40840790 39900738 38430742 37700707
            37430706 37410734 37420772 37620865 37660969
            37610998 37681099 37811160 37871195 38131240
            38611248 39301189 40181173 40631104 40851037