MESOSCALE PRECIPITATION DISCUSSION 0517
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
217 AM EDT TUE AUG 02 2016
 
AREAS AFFECTED...EASTERN MISSOURI 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 020616Z - 021116Z
 
SUMMARY...HIGHLY EFFICIENT BUT SLOW MOVING CELLS MAY POSE
LOCALIZED FLASH FLOOD THREAT THIS MORNING 

DISCUSSION...GOES-E IR AND RADAR MOSAIC SHOW THE RAPID DEVELOPMENT
OF CONVECTION DIRECTLY BENEATH THE CENTER OF THE UPPER LEVEL
ANTICYCLONE JUST NE OF KCOU.  RAP ANALYSIS AND VWP NETWORK SUGGEST
THIS DEVELOPMENT IS ON THE EASTERN EDGE OF STRONGEST 850MB 30KT
JET WHERE IT BECOMES A BIT ANTICYCLONIC. THIS IS ALSO COINSIDENT
WITH THE MOISTURE AXIS WHERE TPW VALUES RANGE FROM 1.75" IN NE MO
TO 2" IN SE MO. INSTABILITY IS A BIT LIMITED COMPARED TO PRIOR
NIGHT'S ACTIVITY DUE TO LACK OF SOLAR INSOLATION TODAY AS WELL AS
WET SOIL CONDITIONS UPSTREAM (WEST). HOWEVER...ALONG THE
ISENTROPIC ASCENT MUCAPES ARE 1500-2000 J/KG MAY INCREASE ACROSS
THE AREA OF CONCERN THROUGH LOW LEVEL ADVECTIVE PROCESSES.  THIS
IS ALL SUGGESTIVE OF RATES IN THE 1.5-2"/HR RANGE AND GIVEN WEAKER
FLOW...CELL MOTIONS OF 5-10KTS WITH 8H-4H CLOUD BEARING LAYER
WINDS SUGGESTIVE OF SEWARD MOTION.  GIVEN UPSTREAM LOW LEVEL
INFLOW AND INSTABILITY GRADIENT...PROPAGATION VECTORS ALSO SUPPORT
SOME SOUTHWESTWARD PROGRESSIONS. THIS MAKES THE EVOLUTION SCENARIO
QUITE MUDDLED WITH LOWER CONFIDENCE...YET HIGH RATES AND SLOW CELL
MOTIONS PRESENT LOCALIZED FLASH FLOODING CONCERNS AS TOTALS IN THE
2-4" RANGE SEEM PLAUSIBLE.  AS TIME PROGRESSES...LLJ WILL TURN
MORE WEST AND NW AND SUPPORT SOME DOWNSTREAM VIGOR TO CONVECTION
MOVING INTO SE MO TOWARD 09-11Z. 

HI-RES GUIDANCE DOES NOT PROVIDE MUCH CONFIDENCE OVERALL AS WELL
GIVEN THE EVOLUTIONARY SPREAD PARTICULARLY NI THE HRRR AND HRRR
PARALLEL OVER THE LAST FEW CYCLES.  HOWEVER 00Z ARW NAM-CONEST AND
ESRL EXP. HRRR SEEM TO BE HANDLING THE SITUATION THE BEST AT THIS
TIME. SUGGESTIVE OF THE SLOW CELL MOTIONS WITH SOME WEAK COLD
POOLS PRESENTING SEWARD PROGRESSION OF DEVELOPMENT UNTIL 12-14Z AS
FORCING FROM UPSTREAM SHORTWAVE/MCS COMPLEX IN E NEB TRACKS
THROUGH N CENTRAL MO INTO NE MO.  

GALLINA

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

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

LAT...LON   40139236 39969162 38649031 37528966 37079015 
            37169068 37979147 39399288 39839296