MESOSCALE PRECIPITATION DISCUSSION 0528
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
849 PM EDT MON JUL 23 2018

AREAS AFFECTED...SOUTHEAST CO/SOUTHWEST KS

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

VALID 240048Z - 240518Z

SUMMARY...THUNDERSTORMS ARE ATTEMPTING TO CONGEAL INTO A LARGER
CLUSTER OVER SOUTHEAST CO.  HOURLY RAIN TOTALS TO 2.5" WITH LOCAL
AMOUNTS TO 4" ARE EXPECTED THROUGH 05Z.

DISCUSSION...EASTERLY UPSLOPE FLOW OF 20-25 KTS COMBINED WITH A
SHORTWAVE MOVING ACROSS NORTHWEST UTAH AND DAYTIME HEATING
GENERATED CONVECTION ACROSS CO/NM WHICH IS STARTING TO MOVE EAST
PARALLEL TO THE 1000-5000 HPA THICKNESS PATTERN NEAR A VAGUE
BOUNDARY AT 850/700 HPA INTO THE HIGH PLAINS.  PRECIPITABLE WATER
VALUES IN THE CENTRAL HIGH PLAINS ARE IMPRESSIVE, WITH VALUES NEAR
1.5".  EFFECTIVE BULK SHEAR OF 25-35 KTS IS HELPING TO ORGANIZE
THE CLUSTER.  AN OUTFLOW BOUNDARY FROM EARLIER CONVECTION IN
WEST-CENTRAL KS IS ALSO HELPING THE CURRENT UPTICK.

THE 18Z HREF PROBABILITIES OF 1"+ AN HOUR SUGGEST THAT HEAVY
RAIN-RELATED ISSUES SHOULD PERSIST UNTIL ROUGHLY 05Z.  THE
EXPECTATION IS FOR THE CLUSTER TO CONTINUE MOVING EAST AT 15 KTS
TO POSSIBLY SLOW DOWN/BROADEN AS IT MOVES THROUGH THE HEART OF THE
INSTABILITY POOL (ML CAPES OF 1500-2000 J/KG & MU CAPES OF
2000-3000 J/KG).  STORMS WITH THE HIGHER RAIN RATES/TOTALS SHOULD
PREFERENTIALLY PROPAGATE IN THE DIRECTION OF WEST-CENTRAL AND
SOUTHWEST KS WHERE THE GREATER INSTABILITY LIES.  HOURLY RAIN
TOTALS TO 2.5" IN CO, AND 2" IN KS, ARE ANTICIPATED GIVEN THIS
DEGREE OF MOISTURE AND INSTABILITY.  MOST OF THE MESOSCALE
GUIDANCE AGREES ON LOCAL AMOUNTS IN THE 4" RANGE DURING THE NEXT
SEVERAL HOURS, WHICH MAY CAUSE ISSUES WHERE HEAVY RAIN FELL
YESTERDAY AND WITHIN URBAN AREAS.

ROTH

ATTN...WFO...BOU...DDC...GLD...PUB...

ATTN...RFC...ABRFC...MBRFC...

LAT...LON   38930287 38880163 37780154 37250197 37140283
            37220353 37330405 38110532 38520570 38500411
            38880316