MESOSCALE PRECIPITATION DISCUSSION 0373
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
254 AM EDT WED JUN 22 2016
 
AREAS AFFECTED...NORTHERN AND EASTERN IA...CENTRAL IL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 220700Z - 221300Z
 
SUMMARY...TRAINING CONVECTION FORMING ON AN AXIS OF ELEVATED
INSTABILITY AND DEEP MOISTURE WILL PRODUCE FLASH FLOODING THROUGH
THE EARLY MORNING HOURS. 

DISCUSSION...REGIONAL RADARS SHOWED CONVECTION FILLING IN ACROSS
EASTERN SD/SOUTHERNMOST MN INTO NORTHEAST IA AND WESTERN IL EARLY
THIS MORNING. THE CONVECTION WAS FORMING ON THE NORTHERN EDGE OF
THE MID LEVEL CAPPING...ALONG AN ELEVATED BOUNDARY EXTENDING FROM
EASTERN SD THROUGH EASTERN IA INTO NORTHERN AND CENTRAL IL. MUCAPE
VALUES ALONG THE ABOVEMENTIONED AXIS RANGED BETWEEN 1000-2000
J/KG...WHERE PRECIPITABLE WATER VALUES RANGE BETWEEN 1.60 AND 1.90
INCHES (PER THE LATEST BLENDED TPW PRODUCT AND THE RAP ANALYSIS. 

THE IR LOOPED SHOWED COOLING TOPS OVER SOUTHERN MN...AS WELL AS
SOUTHEAST IA. SO FAR...MUCH OF THE ELEVATED CONVECTION HAS BEEN
PRODUCING HAIL AS WELL AS HEAVY RAINFALL (AS SEEN ON THE CC
PRODUCT FROM THE KMPX AND KDMX RADARS). HOWEVER...AS MOISTURE IN
THE COLUMN INCREASES...WARM RAIN PROCESSES SHOULD BECOME MORE
IMPORTANT...RESULTING IN MORE EFFICIENT RAINFALL PRODUCERS...AND
INCREASING THE FLASH FLOOD THREAT. 

AS THE 25 TO 35 KNOT LOW LEVEL SOUTHWEST FLOW RUNS UP AND OVER THE
SURFACE BOUNDARY...IT WILL CONTINUE TO PROVIDE A SOURCE OF LIFT
FOR ADDITIONAL CONVECTIVE DEVELOPMENT. THE MID LEVEL FLOW SHOULD
ALLOW THE CONVECTION TO FOLLOW THE AXIS OF BEST ELEVATED
INSTABILITY...RESULTING AN INCREASINGLY FAVORABLE ENVIRONMENT FOR
TRAINING. THE LATEST RAP SHOWED THE MUCAPE MAXIMIZES BETWEEN
09-11Z...BEFORE IT STARTS TO BECOME EXHAUSTED. 

WHILE THERE IS A GOOD MODEL SIGNAL FOR HEAVY RAINFALL...THERE IS A
FAIR AMOUNT OF SPREAD IN THE HIGH RESOLUTION GUIDANCE CONCERNING
WHERE THE THREAT WILL ULTIMATELY BE. THE 00Z WRF ARW APPEARS TO
HAVE THE BEST HANDLE ON THE PLACEMENT OF THE BEST INSTABILITY AND
HIGHEST QPF... THOUGH IT (LIKE MOST OF THE HIGH RESOLUTION
GUIDANCE) HAS BEEN SLOW INCREASING THE CONVECTION TO WHAT IS
OCCURRING NOW. IN CONTRAST...THE LATEST HRRR/EXPERIMENTAL
HRRR/PARALLEL HRRR RUNS SHOW MUCH LIGHTER QPF AMOUNTS FURTHER
NORTHEAST AWAY FROM THE AXIS OF BEST INSTABILITY.

THE 00Z WRF ARW SHOWS A LARGE AXIS OF 3-5 INCHES OF RAINFALL
EXTENDING FROM NORTH CENTRAL IA ACROSS EASTERN IA INTO WEST
CENTRAL IL. GIVEN THE THE SETUP FOR TRAINING AND
BACKBUILDING...THESE VALUES  DO NOT SEEM UNREASONABLE. THESE
RAINFALL AMOUNTS WOULD SUPPORT A FLASH FLOOD THREAT THROUGH 13Z.  

HAYES

ATTN...WFO...ARX...DMX...DVN...EAX...FSD...ILX...LOT...LSX...
MKX...MPX...

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

LAT...LON   43939508 43939419 43799248 43589139 43469103 
            42909014 41868917 41028862 40458845 40038836 
            39508829 38968857 39429049 39849150 40419222 
            41049272 41769326 42299391 43009549 43019575 
            43259620 43509649 43839637 43929572