MESOSCALE PRECIPITATION DISCUSSION 0695
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
548 AM EDT TUE AUG 15 2017

AREAS AFFECTED...NORTHEAST NE...WEST-CENTRAL IA

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

VALID 150945Z - 151345Z

SUMMARY...SLOW-MOVING AND HEAVY SHOWERS AND THUNDERSTORMS WILL
CAUSE SOME POSSIBLE RUNOFF PROBLEMS AND/OR FLASH FLOODING.

DISCUSSION...RADAR IMAGERY IS SHOWING A CLUSTER OF SLOW-MOVING AND
HEAVY SHOWERS AND THUNDERSTORMS OVER AREAS OF NORTHEAST NE IN
ASSOCIATION WITH AN INCREASING WARM ADVECTION PATTERN FOCUSING
OVER THE CENTRAL PLAINS AHEAD OF AN UPSTREAM TROUGH APPROACHING
THE CENTRAL ROCKIES. CONVECTION HAS BEEN ORGANIZING IN AN ELEVATED
FASHION OVER THE REGION...WHICH SOME VERY COLD CONVECTIVE TOPS
SEEN IN GOES IR IMAGERY OVER THE LAST HOUR.

PWATS ACROSS THE REGION ARE AS HIGH AS 1.6 TO 1.7 INCHES WHICH
WITH THE VERY STRONG UPDRAFTS/COLD TOPS HAS BEEN FACILITATING
RAINFALL RATES AS HIGH AS 2.5 INCHES/HR. THE CONVECTION SHOULD
CONTINUE TO GENERALLY ADVANCE OFF TO THE EAST-SOUTHEAST OVER THE
NEXT FEW HOURS AND WILL APPROACH AREAS OF WEST-CENTRAL IA.

EXPECT RAINFALL AMOUNTS OF AS MUCH AS 3 TO 5 INCHES WITH ISOLATED
HEAVIER TOTALS. THE CONCERN IS GENERALLY WITH THE SLOW CELL MOTION
AND HEAVY RAINFALL RATES. SOME RUNOFF AND/OR FLASH FLOODING
CONCERNS ARE POSSIBLE...WITH THE BIGGEST THREAT MAINLY OVER ANY
LOCAL URBAN CENTERS.

ORRISON

ATTN...WFO...DMX...FSD...GID...LBF...OAX...

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

LAT...LON   42839767 42629583 42039523 41519549 41359646
            41489776 41679838 42089888 42569862