MESOSCALE PRECIPITATION DISCUSSION 0066
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
535 AM EDT SUN MAY 26 2013
 
AREAS AFFECTED...CENTRAL AND EASTERN SD...EXTREME SOUTHWEST
MN...EXTREME NORTHWEST IA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 260935Z - 261130Z
 
SUMMARY...SOME ADDITIONAL REPEATING AND LOCALIZED TRAINING OF
CONVECTION IS EXPECTED NEXT COUPLE OF HOURS...FOSTERING SOME
ADDITIONAL SHORT-TERM FLASH FLOOD CONCERNS.

DISCUSSION...LATEST IR SAT IMAGERY SHOWS COLD CONVECTIVE TOPS
ASSOCD WITH BKN MCS ACTIVITY STRETCHING FROM N CNTRL SD SEWD DOWN
ACROSS SERN SD AND INTO NWRN IA WHERE THERE HAS BEEN REPEATING
CONVECTION FOR SEVERAL HOURS NOW. THE LATEST RAP ANALYSIS
INDICATES A PERSISTENT SRLY LOW LEVEL JET ON THE ORDER OF 30 TO 40
KT INTERACTING WITH AN ELEVATED FRONT INVOF 850 MB. THIS IS
CONTINUING TO SUSTAIN A GENERAL NW/SE ORIENTED AXIS OF ENHANCED
ISENTROPIC LIFT AND RESULTING AXIS OF HVY SHOWERS AND
THUNDERSTORMS. MUCAPE VALUES OF 500 TO 1000 J/KG INVOF THE
ELEVATED BOUNDARY CONTINUES TO SUGGEST SUFFICIENT INSTABILITY FOR
ADDITIONAL DEVELOPMENT AT LEAST FOR A COUPLE MORE HOURS...BUT THE
LOW LEVEL JET AND INSTABILITY TRANSPORT SHOULD TEND TO WANE AFTER
SUNRISE. EXPECT ADDITIONAL HVY RAINS...WITH RAINFALL RATES OF 1 TO
1.5 INCHES/HR TO IMPACT SOME AREAS ALREADY HIT BY EXCESSIVE RAINS
OVERNIGHT...AND THEREFORE ADDITIONAL FLASH FLOODING WILL BE
POSSIBLE.

ORRISON


ATTN...WFO...FSD...ABR...

LAT...LON   44779732 44019615 43449575 43139596 43019630 43019665
            43229726 43479766 43769813 44099886 44349976 44690013
            45150015 45339903 44779732