Flash Flood Guidance
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000
AWUS01 KWNH 290513
FFGMPD
MOZ000-IAZ000-KSZ000-NEZ000-290830-

MESOSCALE PRECIPITATION DISCUSSION 0396
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
112 AM EDT WED JUL 29 2015

AREAS AFFECTED...SOUTHERN IA...NORTHERN MO...EXTREME NORTHEAST
KS...SOUTHEAST CORNER NEB

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 290511Z - 290830Z

SUMMARY...RAINFALL RATES OF 1 TO 1.5 INCHES PER HOUR WILL PRODUCE
A THREAT FOR FLASH FLOODING ACROSS A REGION OF LOWER FFG VALUES
EXTENDING FROM THE MID-MISSOURI VALLEY INTO FAR SOUTHERN IOWA. THE
THREAT WILL BE BRIEF HOWEVER...AS A PROGRESSIVE COLD FRONT WILL
SWEEP THROUGH THE REGION BY 0830Z.

DISCUSSION...AT 05Z...RADAR IMAGERY SHOWED HEAVY RAINFALL
EXTENDING FROM FAR SOUTHERN IOWA BACK INTO THE SOUTHEAST CORNER OF
NEBRASKA AND ON INTO NORTHEAST KANSAS AND NORTHERN MISSOURI.  EVEN
THOUGH INDIVIDUAL CELLS ARE MOVING FAIRLY STEADILY TOWARDS THE
EAST...THERE HAS BEEN CONTINUED REDEVELOPMENT CONVECTION BEHIND A
COLD FRONT.  THIS SETS UP THE POSSIBILITY OF FLASH FLOODING
DESPITE THE FAIRLY MODEST RAINFALL RATES.  IN ADDITION...THIS AREA
HAS HAD REPEATED RAINFALLS OVER THE PAST 3 TO 5 DAYS AND FLASH
FLOOD GUIDANCE VALUES ARE CORRESPONDINGLY LOW.

GIVEN THE DEEP MOISTURE IN PLACE...COMBINED WITH THE GOES SOUNDER
DERIVED LI VALUES WHICH SHOWED THAT THE LOWER ATMOSPHERE WAS
CONTINUING TO BECOME MORE UNSTABLE...THINKING IS THAT THE FLASH
FLOODING WILL REMAIN POSSIBLE THROUGH ABOUT 0830Z.  RECENT RUNS OF
THE HRRR AND THE NAM CONEST POINT BOTH POINT BEST QPF HERE. STILL
THINK THAT A PUSH OF DRIER AND MORE STABLE AIR WILL MAKE ITS WAY
INTO THE REGION BEHIND THE COLD FRONT AND REDUCE THE RISK OF
EXCESSIVE RAINFALL.

BANN

...PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT...

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

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

LAT...LON   40879254 40579217 39889236 39239411 38849508
            37899691 38679758 39259743 40029654 40509483
            40799341


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