MESOSCALE PRECIPITATION DISCUSSION 0137
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
745 AM EDT TUE APR 26 2016
 
AREAS AFFECTED...NORTHEAST KS...NORTHWEST/CENTRAL MO 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 261145Z - 261745Z
 
SUMMARY...VERY STRONG THUNDERSTORM WILL EXPAND IN COVERAGE AND
EXPAND EAST-SOUTHEAST THROUGH NORTHEAST KS AND NORTHWEST MO OVER
THE NEXT SEVERAL HOURS. FLASH FLOODING WILL BE POSSIBLE.

DISCUSSION...IR SATELLITE IMAGERY SHOWS VERY COLD CONVECTIVE TOPS
REACHING UP TO ABOUT -70C OVER PARTS OF NORTHEAST KS IN
ASSOCIATION WITH THE NOSE OF A 40 TO 45 KT SOUTHERLY LOW LEVEL JET
THAT IS TRANSPORTING STRONG INSTABILITY INTO A WEST/EAST ORIENTED
STATIONARY FRONT. THE LATEST RAP ANALYSIS SHOWS A VERY STRONG
INSTABILITY GRADIENT IN VICINITY OF THE BOUNDARY WITH MLCAPE
VALUES OF 3000 J/KG POOLED SOUTH OF THE FRONT ACROSS PARTS OF
SOUTHERN KS AND DOWN TO CENTRAL OK.

SPEED CONVERGENCE INTO THE BOUNDARY AND STRONG INSTABILITY POOLING
ALONG THE BOUNDARY SHOULD FOSTER SOME ADDITIONAL CONVECTIVE
ORGANIZATION OVER THE NEXT COUPLE OF HOURS...AND IT APPEARS LIKELY
WE WILL SEE THE EVOLUTION OF A WELL-DEFINED MCS BY LATE THIS
MORNING THAT WILL MOVE EAST-SOUTHEAST ALONG THE INSTABILITY
GRADIENT THROUGH NORTHWEST AND CENTRAL MO. IMPROVING UPPER JET
SUPPORT/DIVERGENT FLOW ALOFT AHEAD OF THE UPPER LOW OVER THE
CENTRAL ROCKIES WILL ALSO PLAY A ROLE IN GENERATING DEEPER LAYER
ASCENT.

THE 00Z NSSL-WRF AND THE 09Z HRRR APPEAR TO HAVE THE BEST OVERALL
HANDLE ON THE CURRENT ACTIVITY...AND THEY SUGGEST ALONG WITH THE
00Z ARW THAT A FAIRLY ROBUST MCS WILL EVOLVE THIS MORNING. ALREADY
THE GOES-OTD DETECTION ALGORITHM IS SHOWING MULTIPLE OVERSHOOTING
TOPS WITH THE ACTIVITY OVER NEMAHA COUNTY...AND WHILE THERE IS A
DISTINCT SEVERE MODE TO THE CONVECTION...THE OVERSHOOTING TOPS
COUPLED WITH A FEW CELL-MERGERS WILL INCREASE RAINFALL RATES
RATHER SHARPLY SUCH THAT SOME OF THESE CELLS MAY PRODUCE OVER 2
INCHES/HR OF RAIN. THE NSSL-WRF AND HRRR GUIDANCE SUPPORTS TOTALS
THROUGH 18Z OF 2 TO 4 INCHES WITH ISOLATED HEAVIER AMOUNTS WHICH
MAY RESULT IN SOME FLASH FLOODING CONCERNS. WILL CONTINUE TO
MONITOR.

ORRISON

ATTN...WFO...EAX...LSX...OAX...SGF...TOP...

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

LAT...LON   40309527 39929351 38999191 38189241 38379422 
            39129597 39619651 40149623