Graphic for MPD #0588

MESOSCALE PRECIPITATION DISCUSSION 0588
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
630 PM EDT FRI JUL 28 2017

AREAS AFFECTED...UT

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

VALID 282230Z - 290200Z

SUMMARY...SLOW CELL MOTIONS IN AN ENVIRONMENT OF HIGH MOISTURE AND
WET SOILS COULD RESULT IN A FLASH FLOOD THREAT INTO THE EVENING
HOURS.

DISCUSSION...THE REGIONAL RADAR MOSAIC SHOWED SCATTERED
CONVECTION...MAINLY TIED TO THE TERRAIN...OVER PORTIONS OF
SOUTHERN AND EASTERN UT. THE CONVECTION WAS FORMING/TRACKING
THROUGH AN AXIS OF 1.25 INCH PRECIPITABLE WATER (AS SHOWN ON THE
MOST RECENT RAP ANALYSIS...AS WELL AS THE MOST RECENT BLENDED TPW
PRODUCT)...WHERE MLCAPE VALUES HOVERED BETWEEN 500-1000 J/KG.
SYNOPTIC SCALE LIFT ASSOCIATED WITH A 50 KNOT JET STREAK IS
ALLOWING THE CONVECTION TO BECOME A BIT BETTER ORGANIZED ACROSS
SOUTHERN UT.

THE KIXC RADAR SHOWED HOURLY RAINFALL RATES NEAR 1.25 INCHES OVER
PORTIONS OF GARFIELD AND KANE COUNTIES...AS THE CELLS MOVE OR
DEVELOP SLOWLY SOUTHEAST. THE MID LEVEL FLOW IS FAIRLY WEAK...WITH
850-300 MB WINDS GENERALLY 10 KNOTS OR LESS. THE SLOW CELL
MOTIONS...COMBINED WITH THE HIGH MOISTURE CONTENT AIR...WILL
CONTINUE TO SUPPORT HOURLY RAINFALL RATES NEAR 1.25 INCHES OVER
AREAS THAT HAVE RECEIVED HEAVY RAINFALL  DURING THE PAST FEW DAYS.

THE MOST RECENT HRRR RUNS SHOWED SCATTERED AREAS OF 1.50 TO 2.00
INCHES...AND BASED ON WHAT HAS OCCURRED ALREADY THIS AFTERNOON...
THE ADDITIONAL RAINFALL AMOUNTS SEEM PLAUSIBLE. THIS MUCH
ADDITIONAL RAINFALL COULD RESULT IN A CONTINUED FLASH FLOOD THREAT
INTO THE EARLY EVENING...WHEN INSTABILITY WANES AND THE CONVECTION
WEAKENS.

HAYES

ATTN...WFO...FGZ...GJT...SLC...

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

LAT...LON   40080934 39580923 37000975 36981148 37061178
            37641213 38641188 39251161 39581085 39921006
           


Last Updated: 631 PM EDT FRI JUL 28 2017