MESOSCALE PRECIPITATION DISCUSSION 0456
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
143 AM EDT TUE JUL 12 2016
 
AREAS AFFECTED...SOUTHEAST NE...SOUTHERN IA...NORTHWEST
MO...NORTHEAST KS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 120545Z - 120945Z
 
SUMMARY...CONVECTION FORMING AHEAD OF A COLD FRONT WILL TAP DEEP
MOISTURE AND INSTABILITY...POSSIBLY LEADING TO FLASH FLOODING
WHERE CELL MERGERS OR TRAINING OCCUR EARLY THIS MORNING.

DISCUSSION...CONVECTION THAT FORMED EARLIER OVER SOUTHWEST IA AND
SOUTHEAST NE CONTINUES TO DROP SLOWLY SOUTH EARLY THIS MORNING.
HOURLY RAINFALL RATES WITH THIS ACTIVITY HAVE APPROACHED 1.75
INCHES ACROSS PORTIONS OF SOUTHWEST IA...AND JUST SOUTH OF KOMA
(BASED ON THE KOAX RADAR). 

MEANWHILE... ADDITIONAL ACTIVITY IS FORMING ACROSS ACROSS PORTIONS
SOUTHEAST NE AND NEARBY NORTHEAST KS...IN AN AXIS OF 2500-3500
J/KG OF MLCAPE. WHILE THE KTWX RADAR HAS INDICATED HOURLY RAINFALL
RATES NEAR 1.50 INCHES...THE DISCRETE CELLS APPEAR TO BE MOSTLY
HAIL PRODUCERS (AND THIS IDEA IS REINFORCED BY THE HAIL REPORTS
OVER NORTHEAST KS).

A 35 TO 45 KNOT LOW LEVEL SOUTHWEST JET WILL TRANSPORT 1.75 TO
2.00 INCH PRECIPITABLE WATER AIR INTO THE REGION... AS MLCAPE
VALUES REMAIN BETWEEN 2500-3500 J/KG (PER THE LATEST RAP) THROUGH
AT LEAST 10Z. THE MOISTURE AND INSTABILITY SHOULD BE SUFFICIENT
FOR CONVECTION TO INCREASE IN COVERAGE ACROSS NORTHEAST KS...WHICH
SHOULD LINK UP WITH THE CONVECTION SOUTH OF KOMA INTO FAR
SOUTHWEST IA. 

THIS SHOULD INCREASE THE THREAT FOR CELL MERGERS IN THE SHORT TERM
ACROSS SOUTHEAST NE INTO FAR SOUTHWEST IA AND NORTHWEST MO.
CORFIDI VECTORS ARE EXPECTED TO BECOME OPPOSED TO THE 850-300 MB
MEAN FLOW... WHICH WOULD ENHANCE THE THREAT FOR TRAINING. AS THE
ACTIVITY BECOME BETTER ORGANIZED...IT COULD BECOME MORE OUTFLOW
DOMINATED AS IT CROSSES NORTHEAST KS AND NORTHWEST MO. WHEN THIS
OCCURS...THE THREAT FOR FLASH FLOODING SHOULD BEGIN TO DIMINISH
AFTER 10Z. 

WHILE THERE IS GOOD HIGH RESOLUTION MODEL AGREEMENT FOR CONVECTION
TO FILL IN ACROSS THE REGION...IT IS NOT AS AGREEABLE AS TO THE
LOCATION/AMOUNT OF RAINFALL. THE LATEST HRRR/HRRR PARALLEL SUGGEST
2-4 INCHES OF RAINFALL IS POSSIBLE...WITH THE HIGHEST AMOUNTS
ACROSS SOUTHEAST NE INTO NORTHWEST MO. ONE HOUR FLASH FLOOD
GUIDANCE VALUES ARE AS LOW AS 1.50 TO 2.00 INCHES ACROSS THIS
AREA...SO FLASH FLOODING IS CONSIDERED POSSIBLE THROUGH THE EARLY
MORNING HOURS.  

HAYES

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

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

LAT...LON   41639192 40009222 38399400 38549607 39429678 
            40049737 40709616 41539405