MESOSCALE PRECIPITATION DISCUSSION 0180...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
756 PM EDT MON JUL 07 2014
 
CORRECTED FOR TYPO IN FIRST PARAGRAPH

AREAS AFFECTED...PORTIONS OF THE LOWER MO VALLEY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 072347Z - 080547Z
 
SUMMARY...INCREASING 850 HPA INFLOW IMPORTING QUALITY MOISTURE AND
INSTABILITY INTO A QUARTET OF SURFACE BOUNDARIES ACROSS THE REGION
COULD CAUSE A FEW INSTANCES OF FLASH FLOODING.

DISCUSSION...AN INVADING SHORTWAVE FROM THE WESTERLIES IS BRINGING
IN A FRESH SURGE OF COOL AIR INTO THE NORTHERN PLAINS IN THE WAKE
OF A SECONDARY FRONT, WHICH HAS FORMED AN ORGANIZED CONVECTIVE
CLUSTER MOVING QUICKLY ACROSS CENTRAL NE.  AMPLE LOW- TO MID-LEVEL
DRY AIR IN AREA SOUNDINGS ALONG WITH HIGH CAPE VALUES HAS AIDED
COLD POOL PRODUCTION ACROSS THE REGION.  TWO OUTFLOW BOUNDARIES
SEEN IN THE 23Z OBSERVATIONS ACROSS SOUTHWEST IA-SOUTHERN NE AND
EASTERN MO-LOWER OHIO VALLEY HAVE CAUSED FAST MOTION TO ORGANIZED
THUNDERSTORM CLUSTERS -- AVERAGING 40 KTS TO THE SOUTHEAST. 
MID-LEVEL CAPPING, REPRESENTED WITH 700 HPA TEMPERATURES OF >12C,
HAS LIMITED ORGANIZED CONVECTION ACROSS KS AND SOUTHEAST NE THUS
FAR.

RECENT RAP RUNS HAVE INDICATED THAT RELATIVELY BROAD 850 HPA
INFLOW INTO THE REGION INCREASES TOWARDS 50 KTS OVER THE NEXT
SEVERAL HOURS WHICH INCREASES PRECIPITABLE WATER VALUES INTO THE
2-2.25" NEIGHBORHOOD, ABOVE THE 99TH PERCENTILE FOR EARLY JULY. 
MID-LEVEL CAPPING/700 HPA COOLING CREATED BY THE UPPER LEVEL
SHORTWAVE'S ADVANCE CAUSES A RETREAT OF THE 12C ISOTHERM INTO KS
AND SOUTHWEST MO WITH TIME.  MOST UNSTABLE CAPE VALUES UPSTREAM
ACROSS THE CENTRAL PLAINS ARE IN THE 4000-6000 J/KG RANGE,
NORMALLY WELL ABOVE WHAT ONE WOULD SEE IN A FLASH FLOOD/ EXCESSIVE
RAINFALL SITUATION.  HOWEVER, HOURLY RAIN RATES OF 2.5" WERE
RECENTLY WITNESSED IN IL, WHICH BEFITS THE MOISTURE AVAILABILITY
IN THE REGION. IT APPEARS FROM RECENT RADAR IMAGERY THAT MULTIPLE
ROUNDS OF CONVECTION COULD MOVE ACROSS THIS PARTIALLY SATURATED
AREA, WITH CELL MERGERS POSSIBLE, WHICH WOULD LEAD TO A QUICK 2-4"
OF RAIN.  THIS MAGNITUDE OF RAINFALL COULD LEAD TO A FEW
OCCURRENCES OF FLASH FLOODING.

ROTH

ATTN...WFO...LSX...DVN...SGF...DMX...EAX...OAX...TOP...GID...
LBF...

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

LAT...LON   40309915 40720015 41330058 41769825 41579495 40389207
            38919002 37659023 37609223 39069584 40309915