MESOSCALE PRECIPITATION DISCUSSION 0080
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
621 PM EDT WED MAY 29 2013
 
AREAS AFFECTED......NORTHEAST KS SOUTHEAST NE TO SOUTHWEST IA... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 292215Z - 300315Z
 
SUMMARY...LINEAR BANDS OF COLD-TOPPED CONVECTION OVER SOUTHEAST NE
AND NORTH CENTRAL KS MOVING NORTH-NORTHEAST POSE POTENTIAL FOR NEW
STORMS OVER AREAS WHERE STORMS OCCURRED EARLIER THIS AFTERNOON OR
LAST NIGHT. AN INCREASE IN FLASH FLOOD POTENTIAL IS EXPECTED OVER
THE NEXT COUPLE OF HOURS. 

DISCUSSION...STRONG DEEP LAYER SOUTHERLY FLOW IS ADVECTING
MOISTURE NORTH ACROSS THE PLAINS STATES.  CLUSTERS AND LINES OF
STORMS HAVE FORMED ACROSS SOUTHEAST NE AND INTO NORTHEAST KS AND
SOUTH CENTRAL KS.  GENERAL BAND MOTION IS TO THE NORTH NORTHEAST
NEAR 40 KT. 

THE BAND IS INTERCEPTING HIGH AVAILABLE MOISTURE WITH PW VALUES
FORECAST TO INCREASE TO 1.5-1.75 INCHES BY 00Z THIS EVENING. 
CONTINUING LOW LEVEL SOUTHERLY FLOW WILL CONTINUE TO ADVECT
MOISTURE TO REPLENISH THAT WHICH FALLS OUT OF THUNDERSTORMS. 

MIXED LAYER CAPES OF 2500-3000 J/KG SHOWN IN THE HIGH RES RAPID
REFRESH COMBINES WITH AREAS OF A COUPLED UPPER DIVERGENCE/LOWER
CONVERGENCE MAXIMA AND STEEP LAPSE RATES OF 7-8 DEG C/KM TO
TRIGGER ASCENT ALONG OUTFLOWS FROM EXISTING CONVECTION. 

THE HIGH RES MODELS INDICATE RAINFALL MAXIMA IN NORTHEAST
KS/SOUTHEAST NE TO FAR NORTHWEST MO AND SOUTHWEST IA.  MUCH OF THE
IA PORTION OF THIS AREA HAS ALREADY HAD SHOWER/STORM ACTIVITY AND
THE REMAINDER OF THE AREA HAD ACTIVITY THE LAST COUPLE OF
NIGHTS...MAKING THE AREA VULNERABLE TO FLASH FLOODING. FLASH FLOOD
GUIDANCE VALUES ARE NEAR AN INCH IN COUNTIES AROUND THE NE/IA/MO
BORDER. FORECAST SOUNDINGS SHOW DEEP SOUTHERLY FLOW WITH ONLY 20
DEGREES OF VEERING SFC-750 MB...SUPPORTING TRAINING ECHOES.
CORFIDI VECTORS RUN OFF THE 18Z GFS INDICATE ONLY 5 KT OF FORWARD
PROPAGATION...ALSO SUPPORTING SLOW EAST BAND PROGRESSION.

PETERSEN


ATTN...WFO...DMX...EAX...OAX...TOP...ICT...GID...

LAT...LON   39079812 40039787 41209740 41989648 42069553 41549482
            40069548 39079596 38409702 38199780 38479811 38799822
            39079812