MESOSCALE PRECIPITATION DISCUSSION 0365
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
716 AM EDT SUN JUL 19 2015
 
AREAS AFFECTED...NORTHEAST KS AND PORTIONS OF MO 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 191115Z - 191615Z
 
SUMMARY...A THUNDERSTORM BAND IS TRYING TO CONSOLIDATE ACROSS THE
AREA NEAR THE EDGE OF THE CAP.  FLASH FLOODING IS POSSIBLE AS
CELLS TRAIN.

DISCUSSION...TWO AREAS OF THUNDERSTORMS ARE BRIDGING TOGETHER
ACROSS NORTHEAST KS AND MO AS AN OUTFLOW BOUNDARY FROM THE MO/IL
CONVECTION MOVES SOUTHWARD AND BEGINS TO INTERCEPT THE 25-40 KT OF
850 HPA INFLOW SEEN ON REGIONAL VAD WIND PROFILES.  A SUBTLE
SHORTWAVE APPEARS TO SHOW UP AS AN AREA OF DARKENING ON WATER
VAPOR IMAGERY NORTHWEST OF THE KS STORM CLUSTER.  A PRECIPITABLE
WATER VALUE OF 2.13" WAS DERIVED BY GPS AT TOPEKA KS WHICH IS
1.5-2 SIGMAS ABOVE THE MEAN FOR MID-JULY.  FLOW ACROSS THE REGION
IS FAIRLY UNIDIRECTIONAL OVER THE TOP OF A SOUTHERN STREAM RIDGE,
WHICH IS ALSO ACTING TO CAP THE ATMOSPHERE NOT TOO FAR SOUTH OF
THE ONGOING THUNDERSTORM ACTIVITY.  THIS PATTERN IMPLIES CELL
TRAINING IS THE MAIN FLASH FLOOD THREAT.

THE EXPECTATION IS FOR THE CONVECTION TO FULLY BRIDGE ACROSS
NORTHWEST MO OVER THE NEXT HOUR OR TWO AND MIGRATE CLOSER TO THE
CAP EDGE AS THE MO PORTION OF THE OUTFLOW BOUNDARY DROPS SLOWLY
SOUTHWARD.  ORGANIZED CONVECTION IS EXPECTED TO MOVE
EAST-SOUTHEAST AT 20-25 KTS PER THE FORWARD PROPAGATING CONVECTIVE
VECTORS AND THE 1000-500 HPA THICKNESS PATTERN IN WHICH THE
CONVECTIVE SYSTEM IS EMBEDDED.  RAP MASS FIELDS ALONG WITH THE
AVAILABLE MLCAPE IN THE REGION SUGGEST THAT THIS COMPLEX COULD
PERSIST FOR ANOTHER 4-5 HOURS UNTIL INSTABILITY IN THE REGION IS
EXHAUSTED AND 850 HPA INFLOW FALLS TO BELOW 25 KTS.  HOURLY RAIN
RATES HAVE OCCASIONALLY REACHED 2.5" PER RADAR IMAGERY, WHICH IS
ENOUGH TO EXCEED THE THREE HOUR FLASH FLOOD GUIDANCE IN THE
REGION.   THE MESOSCALE GUIDANCE ADVERTISES LOCAL AMOUNTS OF 2-4"
IN THIS AREA, WITH THE 00Z NMMB/ITS PARALLEL RUN ALONG WITH THE
00Z WRF4NSSL HAVING THE BEST IDEA OF THE SHAPE/SIZE OF THE
PRECIPITATION PATTERN, THOUGH THEY MIGHT BE A HAIR TOO FAR TO THE
NORTH.  FLASH FLOODING IS CONSIDERED POSSIBLE IN THIS REGION DUE
TO CELL TRAINING.

ROTH

ATTN...WFO...EAX...GID...ILX...LSX...OAX...PAH...SGF...TOP...

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

LAT...LON   40409510 39899140 38898911 37858935 37279031 
            37249112 37579188 38709486 39379727 39979768