MESOSCALE PRECIPITATION DISCUSSION 0065
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
408 AM EDT SUN MAY 26 2013
 
AREAS AFFECTED...NORTHWEST THROUGH EASTERN IA...WESTERN IL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 260806Z - 261130Z
 
SUMMARY...SOME SLOW INCREASE IN REPEATING AND LOCALIZED TRAINING
OF CONVECTIVE CELLS IS EXPECTED OVER THE NEXT COUPLE OF HOURS.

DISCUSSION...LATEST IR SAT IMAGERY SHOWS A NW/SE ORIENTED BAND OF
ELEVATED CONVECTION WHICH HAS BEEN ATTEMPTING TO ATTAIN A BIT MORE
ORGANIZATION THE LAST COUPLE OF HOURS. LATEST SAT/RADAR TRENDS
SHOW A GRADUAL INCREASE IN THE DEGREE OF REPEATING CONVECTIVE
CELLS OVER CNTRL IA...AND THIS APPEARS TO BE ASSOCD WITH AN
INCREASE IN THE SWLY LOW LEVEL JET OVER THIS AREA WITH THE FLOW
REACHING 30 TO 40 KTS. A POOL OF HIGHER PWATS ON THE ORDER OF 1.5
INCHES AS PER LATEST RAP ANALYSIS IS SEEN POOLED OVER SRN IA AND
NRN MO...AND THE INCREASE IN LOW LEVEL JET ENERGY SHOULD ALLOW
SOME OF THIS DEEPER MOISTURE TO OVERRUN THE SURFACE WARM FRONT
OVER THE N CNTRL PLAINS AND IN PARTICULAR INTERACT WITH A
WELL-DEFINED 850 MB TROF/ELEVATED WARM FRONT OVER CNTRL/SERN IA
WHERE MUCH OF THE ONGOING CONVECTION IS ROOTED. SUSTAINABLE
ISENTROPIC LIFT COUPLED WITH A FAVORABLE THERMODYNAMIC ENVIRONMENT
FOR ELEVATED CONVECTION THE NEXT FEW HOURS WILL SUPPORT A NW/SE
ORIENTED AXIS OF HEAVY SHOWERS AND THUNDERSTORMS WITH A LIKELIHOOD
FOR REPEATING CONVECTIVE CELLS AND LOCALIZED AREAS OF TRAINING.
ALSO OF NOTE...WILL BE THE MORE ORGANIZED MCS ACTIVITY OVER NWRN
IA ATTM...WHICH IS LIKELY TO PROPAGATE SEWD INVOF THE ELEVATED
BOUNDARY. THEREFORE...EXPECTING A THREAT FOR FLASH FLOODING ACROSS
THE REGION. WILL CONTINUE TO MONITOR.

ORRISON


ATTN...WFO...ILX...DVN...ARX...MPX...DMX...FSD...

LAT...LON   40149065 40679137 41139211 41369259 41769343 42059422
            42139523 42339578 42769589 43319551 43519462 43359320
            42889200 42329119 41369022 40618972 40108984 39929020
            40149065