MESOSCALE PRECIPITATION DISCUSSION 0239
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1154 AM EDT THU MAY 26 2016
 
AREAS AFFECTED...MID-MISSISSIPPI VALLEY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 261553Z - 262153Z
 
SUMMARY...THUNDERSTORMS ARE BEGINNING TO SHOW SIGNS OF TRAINING
ACROSS SOUTHEAST MO.  WITH HOURLY RAIN RAIN RATES UP TO 2"
POSSIBLE, FLASH FLOODING IS POSSIBLE OVER AN AREA OF PARTIALLY
SATURATED SOILS.

DISCUSSION...THUNDERSTORMS ACROSS SOUTHEAST MO ARE SHOWING COOLING
CLOUD TOPS AS THEY APPROACH AN AREA OF SIGNIFICANT INSTABILITY
NEAR THE CONFLUENCE OF THE OH AND MS RIVERS.  THEY ARE ALSO
SHOWING HINTS OF TRAINING AS THEY RIDE NORTH OF A STALLING OUTFLOW
BOUNDARY.  PRECIPITABLE WATER VALUES ARE NEAR 1.75" PER RAP
FORECAST FIELDS.  MLCAPES JUST SOUTH OF THE REGION ARE 2000-3000
J/KG WHICH ARE BEING IMPORTED INTO THE AREA ON THE HEELS OF
CONVERGING SOUTHWEST INFLOW OF 20-30 KTS.

THE EXPECTATION IS FOR MLCAPES TO APPROACH 4000 J/KG LATER TODAY
ACROSS WESTERN TN, WHICH WILL ADD FUEL TO THE FIRE FOR STRONG
UPDRAFTS WITH TIME.  RAP FORECAST FIELDS INDICATE THAT THE 850 HPA
FLOW SHOULD BACK SOMEWHAT AND INTENSIFY IN THE NEXT FEW HOURS,
WHICH COULD ALLOW FOR SOME BACKBUILDING ACROSS SOUTHEASTERNMOST
MO.  THE RAP, TRIO OF HRRR RUNS, AND 12Z SPCWRF SHOW A SIGNAL FOR
LOCAL AMOUNTS IN THE 3-5" RANGE, WHICH COULD FALL QUICKLY.  THE
AVAILABLE MOISTURE ALLOWS FOR HOURLY RAIN RATES UP TO 2", WHICH
COULD BE EXCEEDED IN LONGER TRAINING BANDS OR WHERE CELLS MERGE. 
MORE ORGANIZED CONVECTIVE CLUSTERS SHOULD MOVE TO THE
EAST-SOUTHEAST AT 20 KTS, WHICH IS A COMPROMISE BETWEEN THE
FORWARD PROPAGATING CONVECTIVE VECTORS AND THE 1000-500 HPA
THICKNESS PATTERN.  LESS ORGANIZED ACTIVITY SHOULD MOVE JUST NORTH
OF DUE EAST AT 25 KTS, WHICH COULD LEAD TO CELL MERGERS WITH MORE
ORGANIZED CLUSTERS.  CONSIDERING RECENT RAINFALL, FLASH FLOODING
IS A CONCERN.

ROTH

ATTN...WFO...LSX...MEG...OHX...PAH...SGF...

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

LAT...LON   37928988 37748793 36388762 35858877 35989000 
            36629137 37419225 37769139