MESOSCALE PRECIPITATION DISCUSSION 0245
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
941 PM EDT THU JUN 18 2015
 
AREAS AFFECTED...SOUTHERN MISSOURI...SOUTHERN ILLINOIS... NORTHERN
ARKANSAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 190200Z - 190800Z
 
SUMMARY...REDUCING RAIN RATES AND TOTALS STILL POSE FLASH FLOOD
THREAT THOUGH LIKELY TRANSITIONING TO LONGER DURATION STYLE EVENT. 

DISCUSSION...RAIN RATES AND OVERALL RAIN TOTALS CONTINUE TO
DECREASE WITH BILL PARTICULARLY NEAR THE CENTER AS SYSTEM
TRANSFERS TO POST-TROPICAL CYCLONE.  THE MAIN CORE OF HEAVIEST
RAINS AND TOTALS IN THE 2-3" RANGE WILL BE FOCUSED ALONG
SHARPENING DEFORMATION ZONE FROM SOUTHWEST MISSOURI ACROSS CENTRAL
MISSOURI...AS NORTHERN STREAM FRONTAL ZONE BEGINS TO INTERACT WITH
THE CYCLONE AS WELL. VISIBLE/IR SATELLITE LOOPS SHOW THE
DEEPER/COLDER CLOUDS ARE MORE WISPY AND GLACIATED IN NATURE WITH
INCREASING MID-LEVEL BAROCLINIC LEAF STRATIFORM... WITH EMBEDDED
WEAK CONVECTIVE ELEMENTS NORTHEAST OF THE LOW...THIS IS RELATED TO
SOME GENTLE UPGLIDE OVER SFC WIND SHIFT/TROF TAPPING A WEAK AXIS
OF 1000 J/KG MUCAPE FROM SGF TOWARD MVN.  STILL THIS SHOULD
MAINTAIN THE .5"/HR RATES WITH THE EMBEDDED 1-1.25"/HR RATES WITH
THESE CONVECTIVE ELEMENTS...GIVEN VERY DEEP MOIST PROFILES THAT
STILL EXIST OVER CENTRAL ARKANSAS... UP TO 2.0" TOTAL PWATS.   

SOUTH OF THE BOUNDARY IN ARKANSAS... 
THE RECENT HRRR AND NMMB GIVE THOUGHTS OF BILL BEGINNING TO EXPAND
ITS ELONGATION SW TO NE WITH PIECE OF SHORTWAVE ENERGY OR
VORTICITY LOBE ROTATING AROUND THE BASE TOWARD 03-04Z.  THIS
ALLOWS DEEPER ROOTED CONVECTION ACROSS CENTRAL ARKANSAS TO TAP
MODERATE 1500-2000 J/KG INSTABILITIES AND LIFT NORTHEASTWARD
ACROSS NORTH CENTRAL ARKANSAS/SOUTHEAST MISSOURI WITH SOME
TRAINING ELEMENTS TOWARD THE END OF THE DISCUSSION PERIOD. ALSO AT
THE LEADING EDGE OF THE SURGE OF ENERGY SHOULD INITIATE CONVECTION
IN THE 06-08Z TIME FRAME FURTHER EAST ALONG THE BOUNDARY INTO
SOUTHERN ILLINOIS.  GIVEN INTERACTION WITH THE DEFORMATION
ZONE...CELL MOTIONS WILL BE SLOWED...INCREASING THREAT FOR
ISOLATED ENHANCED TOTALS ACROSS AN AREA OF LOWERED FLASH FLOOD
GUIDANCE TO INCREASE THE FLASH FLOOD THREAT INTO THE EARLY
MORNING.        

GALLINA

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

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

LAT...LON   39418860 38818831 37988910 37178989 35809088 
            34889156 35049225 35449268 35609327 35739418 
            35839437 36329449 36929430 37869337 38819088