MESOSCALE PRECIPITATION DISCUSSION 0051
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
708 PM EDT SUN MAY 19 2013
 
AREAS AFFECTED...NORTHEAST KS...NORTHWEST MO...SOUTHWEST THROUGH
NORTHEAST IA...SOUTHEAST MN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 192305Z - 200300Z
 
SUMMARY...GROWING POTENTIAL FOR CONVECTIVE CLUSTERS TO MERGE THE
NEXT FEW HOURS...WITH THE STORM MODE TENDING TO BECOME
QUASI-LINEAR...AND SUPPORTING AN AXIS OF ENHANCED RAINFALL VIA
TRAINING OF CONVECTIVE CELLS.


DISCUSSION...VERY COLD-TOPPED CONVECTION WITH AN OVERWHELMINGLY
SEVERE MODE ATTM IS EXPECTED TO EVOLVE INTO A RELATIVELY LARGE
SCALE QLCS...WITH AN AXIS OF ENHANCED RAINFALL POTENTIAL APPEARING
TO SET UP ALONG AND ESP TO THE LEFT OF A STATIONARY FRONT ORIENTED
SW/NE FROM NERN KS NEWD UP INTO SERN MN. ALREADY SEEING PLENTY OF
EVIDENCE OF AN MCV OVER E CNTRL KS ATTM ASSOCIATED WITH MERGING
SEVERE MODE CONVECTION. THIS MCV IS LIKELY TO INTENSIFY THE NEXT 2
TO 3 HOURS AND MOVE ENEWD INTO NWRN MO. ALL THE WHILE...THE 12Z
ECMWF AND 18Z NAM-CONEST SUPPORT AN INTENSIFYING MOIST LOW LEVEL
JET BETWEEN 00Z AND 06Z...REACHING UPWARDS OF 40 TO 50 KTS AIMING
NORTH OUT OF CNTRL/NRN MO INTO THE VICINITY OF THIS STATIONARY
FRONT. THE MCV SHOULD ACT TO ENHANCE THIS MOISTURE TRANSPORT.
SBCAPE VALUES OF 3000 J/KG OVER MUCH OF MO/SERN IA WILL SUPPORT
MORE THAN ENOUGH THERMODYNAMIC SUPPORT FOR SUSTAINABLE CONVECTION
INVOF THE FRONT. THE MCV WILL SUPPORT AN ELEVATED CONVECTIVE MODE
TO THE LEFT OF THE STATIONARY FRONT. MEAN LAYER FLOW IS SWLY OVER
THE BOUNDARY...AND SO THERE IS AN ENHANCED THREAT FOR
TRAINING/REPEAT CONVECTION THROUGH THE EVENING. RAINFALL RATES OF
2 TO 2.5 INCHES/HR ARE POSSIBLE...AND THIS WILL DRIVE AN ELEVATED
FLASH FLOOD THREAT OVER THE NEXT SEVERAL HOURS AT LEAST.

ORRISON


ATTN...WFO...ARX...MPX...DMX...EAX...OAX...TOP...

LAT...LON   40279629 40569619 41529554 42699458 44009360 44449288
            44309204 43619208 42129309 40999399 40069443 39219477
            38679525 38599602 38699641 39149663 39839649 40279629