MESOSCALE PRECIPITATION DISCUSSION 0225
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
206 PM EDT TUE JUN 16 2015
 
AREAS AFFECTED...SOUTHERN MISSOURI...SOUTHERN ILLINOIS...NORTHWEST
ARKANSAS...FAR WESTERN KENTUCKY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 161805Z - 170005Z
 
SUMMARY...DEVELOPING HIGHLY EFFICIENT RAINFALL PRODUCING CELLS
WITH RATES 2-2.5"/HR COULD TRAIN AT TIMES LEADING TO POTENTIAL
FLASH FLOODING THROUGH 00Z. 

DISCUSSION...VERY MOIST ENVIRONMENT EXISTS ACROSS THE OZARKS INTO
SOUTHERN ILLINOIS SOUTH OF A FLATTENING COLD FRONT.  THE 12Z SGF
SOUNDING SHOWED A SKINNY PROFILE WITH WEAK LAPSES RATES AS IT WAS
WELL SATURATED THROUGH ANY CONVECTING LAYER. THIS IS EXPRESSED
WELL WITH TOTAL PWATS IN THE 2-2.25" RANGE.  WITH CLEAR
SKIES...INCREASED SOLAR INSOLATION HAS ALLOWED FOR CAPES TO GROW
INTO THE 2500-3000 J/KG RANGE EVEN WITH THE WEAK LAPSES
RATES...THIS SHOULD PROVIDE VERY EFFICIENT RAINFALL PRODUCTION FOR
ANY CONVECTION THAT DOES DEVELOP QUICKLY LEADING TO RAIN RATES OF
2-2.5"/HR LIKELY...POSSIBLY HIGHER IN SPOTS OF INCREASED
CONVERGENCE/FLUX.  HOWEVER...FORCING HAS BEEN LIMITED TO WEAK SFC
TO 925MB MOISTURE CONVERGENCE NEAR OR SOUTH OF THE BOUNDARY...
POTENTIALLY EVEN ON HIGHER HILLS/TOPOGRAPHY IN THE REGION.  AS
SUCH...THE ORGANIZATION OF THE CONVECTION COULD REMAIN SPOTTY OR
RANDOM FOR THE FIRST FEW HOURS.  THIS IS IN LINE WITH NEARLY ALL
HI-RESOLUTION MODEL GUIDANCE SHOWING ISOLATED TRACKS OF HIGH
TOTALS....THOUGH SSEO MEAN HELPS DELINEATE THE ZONE OF HIGHEST
POTENTIAL FROM NEAR SGF TO MVN...

NEAR ZERO WIND SHEAR THROUGH THE CLOUD BEARING LAYER...IE
UNIDIRECTIONAL SPEEDS IN THE 20-30KT RANGE THROUGH THE CLOUD
BEARING IS ALSO PARALLEL TO THE FRONT ALLOWING FOR WSW TO ENE
ORIENTED CONVECTING LINE TO POTENTIALLY TRAIN FOR ENHANCED
RAINFALL TOTALS...INCREASING THE THREAT FOR FLASH FLOODING BY 00Z.
   

GALLINA

ATTN...WFO...LSX...LZK...MEG...PAH...SGF...TSA...

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

LAT...LON   38768922 38078837 36748856 36539014 35759227 
            34919415 35959438 36539443 37369434 37939370 
            38439232 38639098 38669041