MESOSCALE PRECIPITATION DISCUSSION 0519
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1103 PM EDT TUE AUG 02 2016
 
AREAS AFFECTED...MISSOURI...EXT SOUTHWEST ILLINOIS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 030300Z - 030900Z
 
SUMMARY...ANOTHER ROUND OF SLOW MOVING ELEVATED CONVECTION WITH
HIGH RAINFALL EFFICIENCY ACROSS AREAS SATURATED FROM PRIOR EVENTS
OVER THE LAST WEEK.  THIS COULD POSE ANOTHER THREAT FOR FLASH
FLOODING PARTICULARLY ACROSS E CENTRAL MO STARTING AROUND 06-07Z. 

DISCUSSION...GOES-E IR/WV LOOP SHOWS WELL DEFINED BUT WEAKENING
MCV SLIDING SSE SLOWLY INTO MO WITH FAIRLY WELL DEFINED PSEUDO
WARM FRONT/ELEVATED BOUNDARY EXTENDING SE VERY NEAR THE MS RIVER
FROM SE IA INTO FAR SW. CLEAR SKIES TODAY HAS SUPPORTED SOME
INSOLATION TO REPLENISH INSTABILITY ACROSS MUCH OF MO MAXIMIZED
NORTH OF WEAK DYING FRONTAL BOUNDARY.  THIS FRONTAL BOUNDARY THAT
EXTENDS FROM THE BOOTHEEL TO JUST NORTH OF JLN/SGF WHERE THERE IS
AN NORTHWARD KINK OR INFLECTION.  THIS DUE TO SOME MAXIMIZING
CONVERGENCE TO SPARK  ISOLATED DEEP CONVECTION JUST AS THE CAP
BEGINS TO REINFORCE WITH LOSS OF DAY TIME HEATING.  EXPECTATION IS
FOR CELLS REMAIN GENERALLY WEAK/ISOLATED GIVEN THE LACK OF
PERSISTENT FORCING AT THIS TIME...WAITING FOR ISENTROPIC ASCENT
FROM STRENGTHENING LLJ TO FOCUS UPSCALE GROWTH.  

THE SHORTWAVE IR AND IR ALSO INDICATE  A WEAK TROWAL/CONVERGENCE
ZONE EXTENDS FROM THE WEAK SURFACE INFLECTION N OF SGF NNE TOWARD
THE MCV JUST WEST OF IRK...THIS WILL LIKELY DENOTE THE WESTERN
BOUNDARY OF THE LOW LEVEL JET/ISENTROPIC ASCENT CHANNEL. 
CURRENTLY VWP INDICATES WINDS OF 15-20 SELY...WHICH MATCHES WELL
TO RAP ANALYSIS WHICH BY 06-07Z INCREASES TO 20KTS WHILE
MAINTAINING SOLID MST TRANSPORT.  MUCH OF THE HI-RES GUIDANCE ALSO
SUPPORTS THE IDEA OF MAXIMIZING LLJ CONVERGENCE ALONG THE ELEVATED
PSEUDO WARM FRONT NEAR THE MCV ACROSS E MO...LIKELY ALONG OR JUST
EAST OF THE AREA SATURATED BY YESTERDAY'S EARLY MORNING
CONVECTION.  MUCAPES IN THE 3000-4000 J/KG RANGE AND TPWS UP TO
2.0" WILL MAKE RAINFALL PRODUCTION EFFICIENT BUT LIMITING FACTOR
WILL BE THE WEAKER WINDS AT 15-20KTS AND LOWER FLUX THAN THE PRIOR
TWO EVENING'S EVENTS.  HOWEVER...WITH WEAKER FORCING ALSO COMES
WEAKER CELL MOTIONS ALLOWING FOR COMPOUNDING TOTALS.  AS SUCH AHPS
ANALYSIS INDICATES A BROAD ZONE WITHIN THE AREA OF CONCERN WITH
RAINFALL OVER THE LAST 7 DAYS GREATER THAN  200% OF NORMAL.  FLASH
FLOODING COULD BE POSSIBLE PARTICULARLY ACROSS E CENTRAL MO
NEAR/IN ADVANCE OF MCV TRACK AND LIKELY IF THE CONVECTION TRACKS
ACROSS THE AREAS AFFECTED LAST EVENING IN KNOX TO CALLAWAY
COUNTIES.  

GALLINA

ATTN...WFO...EAX...LSX...SGF...

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

LAT...LON   40169240 39979134 39459047 38568982 37949046 
            37579191 37379363 37829413 38939303 39579264