MESOSCALE PRECIPITATION DISCUSSION 0235
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
258 PM EDT WED JUN 17 2015
 
AREAS AFFECTED...SOUTHERN MISSOURI....SOUTHERN
ILLINOIS...SOUTHWEST INDIANA...WESTERN KENTUCKY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 171857Z - 180057Z
 
SUMMARY...INCREASING HIGHLY EFFICIENT DEEP CONVECTION SHOULD
PRODUCE RATES IN EXCESS OF 2"/HR WITH THE POSSIBILITY OF TRAINING
TO LEAD TO POSSIBLE FLASH FLOODING.   

DISCUSSION...VISIBLE IMAGERY CONTINUES TO SHOW THE OUTFLOW CHANNEL
FROM TROPICAL DEPRESSION BILL ACROSS SOUTHWEST MISSOURI TO CENTRAL
ILLINOIS. SOUTH OF THIS AREA...SOLAR INSOLATION HAS ALLOWED FOR
INCREASED INSTABILITIES WITH SBCAPES IN THE 2500-3000 J/KG RANGE. 
REDUCED CAPPING HAS LED TO CONVECTIVE INITIATION ALONG THE
SOUTHERN PORTION OF THE CLOUDY REGION ACROSS SOUTHEAST MO INTO SW
INDIANA.  THESE CELLS REMAIN IN A VERY DEEP MOISTURE ENVIRONMENT
WITH 2"+ TOTAL PWATS AND LIMITED DRY AIR THROUGHOUT THE PROFILE
ALLOWING FOR HIGHLY EFFICIENT RAINFALL PRODUCTION LIKELY IN THE
2-2.5"/HR RANGE. SOME POSSIBILITIES FOR STRONGER CELLS ARE
EXPECTED WITH INCREASED UVVS FROM BEING LOCATED WITHIN PREFERABLE
RIGHT ENTRANCE OF STRENGTHENING UPPER LEVEL JET.  THE STRONGER JET
ALOFT ALLOWS FOR DECENT CELL MOTIONS TOWARD THE ENE...BUT
UNIDIRECTIONAL FLOW PROVIDES A GOOD POSSIBILITY FOR TRAINING OF
CELLS FROM WSW TO ENE. GIVEN THE ORIENTATION OF THE CU BANDS SEEN
ACROSS THE REGION IN VISIBLE IMAGERY...THE POSSIBILITIES FOR
TRAINING ARE INCREASED.   LASTLY...UPSTREAM PROPAGATION VECTORS
ARE VERY LIGHT WITH SOME INDICATIONS FOR BACKBUILDING...
PARTICULARLY OVER SOUTHERN MO...AS LOW LEVEL FLOW INCREASES WITH
THE APPROACH OF T.D. BILL.   

OVER SOUTHWEST MISSOURI...
OUTFLOW CHANNEL FROM TROPICAL CYCLONE BILL HAS REMAINED RELATIVELY
STATIONARY OVER THE AREA REDUCING THE SOLAR INSOLATION FOR THE
INCREASED INSTABILITIES FOR DEEPER CONVECTION.  HOWEVER...THE
LIMITED AMOUNT OF CAPE THAT IS AVAILABLE IS BEING TAPPED BY
INCREASED DIVERGENCE FOR SOME ELEVATED CONVECTION.  SINCE THE
CELLS ARE WITHIN THE NARROW OUTFLOW CHANNEL... PROFILE IS
EXTREMELY SATURATED SO CELL EFFICIENCY SHOULD SUFFICE FOR RATES
OVER 1"/HR WITHIN UNIDIRECTIONAL FLOW FOR THE POTENTIAL FOR
INCREASED TRAINING LIKELY ACROSS THE CORRIDOR FROM DADE TO
LACLEDE/CAMDEN COUNTIES THAT WAS AFFECTED LAST EVENING...FOR THE
POTENTIAL TO EXCEED THE LOW FLASH FLOOD GUIDANCE HERE AS WELL. 

GALLINA

ATTN...WFO...ILX...IND...LMK...LSX...MEG...PAH...SGF...

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

LAT...LON   39438690 38608620 37658660 36788808 36488995 
            37099150 36799430 37909407 38799150 39138933