MESOSCALE PRECIPITATION DISCUSSION 0381
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
302 AM EDT SAT JUL 25 2015
 
AREAS AFFECTED...NORTHERN MO...SOUTHWEST IA...EXTREME SOUTHEAST
NEB 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 250701Z - 251200Z
 
SUMMARY...INSTABILITY...DEEP MOISTURE AND MODEST LOW LEVEL FORCING
WILL HELP SUSTAIN STORMS CAPABLE OF PRODUCING RAINFALL RATES IN
EXCESS OF 2 INCHES PER HOUR.  GIVEN RAINFALL EARLIER IN THE
EVENING IN ABOUT THE SAME PLACE SUGGESTS THAT FLASH FLOODING WILL
BE POSSIBLE THROUGH 12Z. 

DISCUSSION...A STATIONARY FRONT EXTENDED FROM NORTH TO SOUTH
ACROSS CENTRAL IA AND MO AT 05Z.  GOES IMAGERY SHOWED THAT STORMS
COMING OUT OF EXTREME SOUTHEAST NEB AROUND 0630Z WILL BE MOVING
INTO AN AREA WHERE CAPE VALUES WERE STILL IN THE RANGE OF 2000 TO
3000 J PER KG...WHICH WAS THE SAME REGION WHERE 00Z RAOBS SHOWED
THETAE VALUES WERE IN THE 355K TO 360K RANGE AT H85.  SOUTHWEST
WINDS IN THE LOW LEVELS WERE ONLY IN THE 20 KT TO 25 KT
RANGE...BUT THEY WERE TAPPING DEWPOINTS OVER EASTERN KS WHICH WERE
IN THE MID TO UPPER 70S AND TRANSPORTING THAT AIRMASS TOWARDS THE
SURFACE AND LOW LEVEL BOUNDARY.  AS A RESULT...THINK THAT THE
STORMS SHOULD CONTINUE TO HAVE A SOURCE OF DEEP LEVEL MOISTURE AS
THEY MOVE INTO A SOMEWHAT DRIER ENVIRONMENT.  LOW LEVEL LIFT
SHOULD BE AIDED ONCE THE AIR REACHES THE LOW LEVEL BOUNDARY AND
ASCENDS ISENTROPICALLY.    

FLASH FLOOD GUIDANCE IS GENERALLY IN EXCESS OF 2 INCHES PER 3
HOURS.  EVEN SO...THE STORMS MOVING INTO NORTHERN MO WILL BE
MOVING ACROSS AN AREA WHICH ALREADY HAD ONE ROUND OF MDT TO
LOCALLY HEAVY RAIN EARLIER ON FRIDAY EVENING.  THUS THERE COULD BE
A RISK OF FLASH FLOODING WHICH PERSISTS THROUGH THE NIGHT.  

THE 05Z RAP AND HRRR PICKED UP ON THE AXIS OF HEAVIEST RAINFALL
AND SEEMED TO SUGGEST THE COMPLEX INITIALLY OVER SOUTHEAST NEB
WILL BE TAKING ON A MORE SOUTHEAST TRAJECTORY.  


BANN

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

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

LAT...LON   41039516 40829350 39899204 39169258 39379383 
            39869489 40099571