MESOSCALE PRECIPITATION DISCUSSION 0362
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1130 PM EDT FRI JUN 17 2016
 
AREAS AFFECTED...PORTIONS OF CENTRAL AND NORTHEAST
NEB....SOUTHEAST SD....FAR NORTHWEST IA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 180330Z - 180730Z
 
SUMMARY...MERGING CLUSTERS OF THUNDERSTORMS OVER THE NEXT COUPLE
OF HOURS WILL GENERATE SOME VERY HEAVY RAINFALL AND POSSIBLE FLASH
FLOODING.

DISCUSSION...AN IMPRESSIVELY COLD-TOPPED MCS WITH NUMEROUS
OVERSHOOTING TOPS AS PER THE GOES-OTD ALGORITHM IS SEEN ADVANCING
SOUTHWEST OUT OF SOUTHEAST SD AND INTO NORTHEAST NEB.
MEANWHILE...A MORE DISORGANIZED AREA OF CONVECTION AROUND THE
NORTHEAST FLANK OF THE MCS OVER KS AND SOUTHERN NEB IS LIFTING
ERRATICALLY NORTH OR NORTHEAST THROUGH NORTH-CENTRAL NEB. ALTHOUGH
THE CONVECTION IS NEARLY STATIONARY IN SOME AREAS.

OVER THE NEXT COUPLE OF HOURS...THERE IS EXPECTED TO BE NUMEROUS
CELL-MERGERS AND OVERSHOOTING TOPS ASSOCIATED WITH THIS CONVECTION
WHICH WILL PRODUCE AT LEAST LOCALLY SOME PROLIFIC RAINFALL RATES
THAT MAY EXCEED 3 INCHES/HR. THE THERMODYNAMIC ENVIRONMENT IS
HIGHLY UNSTABLE WITH MLCAPE VALUES OF 4000 TO 4500 J/KG ACROSS
PARTS OF NORTHERN NEB.

THE HRRR/HRRP GUIDANCE HAS A BIT OF A BETTER HANDLE ON THIS
CONVECTION AND SUGGESTS AS MUCH 4 TO 6 INCHES OF RAINFALL
POTENTIAL FOR THIS VALID PERIOD WHICH WILL MAINTAIN THE FLASH
FLOOD THREAT. THE CONVECTION SHOULD GRADUALLY WEAKEN THOUGH LATER
IN THE NIGHT AS THE MERGING CONVECTION EXHAUSTS THE AVAILABLE
INSTABILITY...AND THESE CONVECTIVE TRENDS WILL BE MONITORED.

ORRISON

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

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

LAT...LON   44179709 44029641 43299590 42569577 42049598 
            41579660 41359762 41289839 41319901 41619976 
            42090002 42689980 43329894 43929790