MESOSCALE PRECIPITATION DISCUSSION 0185
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
530 PM EDT MON JUL 29 2013
 
AREAS AFFECTED...SOUTHERN AND EASTERN KS...FAR NORTHERN
OK...SOUTHWESTERN MO 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 292125Z - 300130Z
 
SUMMARY...DEVELOPING CLUSTERS OF INTENSE CONVECTION WILL BECOME
BETTER ORGANIZED WITH TIME AND LIKELY MERGE RESULTING IN A LARGER
SCALE MESOSCALE CONVECTIVE SYSTEM BY LATER THIS EVENING. A HIGH
THREAT FOR BACK-BUILDING AND TRAINING CONVECTION WILL SUPPORT
POTENTIAL FOR A HIGH-IMPACT FLASH FLOOD EVENT THIS EVENING.

DISCUSSION...STRONG DIURNAL HEATING OVER THE S CNTRL AND SRN
PLAINS LATE THIS AFTERNOON IS RESULTING IN REGIONAL SBCAPE VALUES
OF 3500 TO 4500 J/KG...WITH A N/S ORIENTATION THAT INTERSECTS A
STRONG AND NEARLY STATIONARY FRONT SITUATED W/E ACROSS SRN KS AND
THEN EWD INTO SWRN MO. AIDING THE STRONGLY UNSTABLE AIRMASS IS A
POOL OF DEEP TROPICAL MOISTURE WHICH HAS BEEN SURGING NWD
THROUGHOUT THE DAY. IN FACT...SFC DEWPOINTS OVER CNTRL OK HAVE
REACHED THE MID 70S...AND COLUMN TPW BASED ON THE LATEST RAP
ANALYSIS IS 2.0 TO 2.2 INCHES FROM THE RED RIVER VALLEY NORTH INTO
CNTRL/ERN KS.

CONVECTION IS RAPIDLY DEVELOPING ATTM ALONG AN AGITATED CU/TCU
FIELD ACROSS SWRN/CNTRL KS AND IS BEING DYNAMICALLY SUPPORTED BY
AN APPROACHING SHORTWAVE TROUGH EXITING ERN CO AND MOVING ACROSS
WRN KS. IT IS EXPECTED THAT CONVECTION WILL INTENSIFY AND FURTHER
ORGANIZE THROUGH THE LATE-AFTERNOON AND EARLY EVENING HOURS AND
EVENTUALLY EVOLVE EASTWARD INTO MERGING AND BACK-BUILDING CLUSTERS
OF CONVECTION AS THE SHORTWAVE MOVES EAST INVOF THE FRONT. THIS
ULTIMATELY WILL LEAD TO A LARGER SCALE MCS LATER IN THE EVENING.
RAINFALL RATES OF 2 TO 3 INCHES/HR ARE EXPECTED.

LATEST RAP ANALYSIS SHOWS NEARLY PARALLEL MEAN LYR FLOW INVOF THE
AFOREMENTIONED W/E ORIENTED FRONT. THIS COUPLED WITH AN
INTERSECTING AND STRENGHTENING LOW LVL JET ALSO HIGHLY SUGGESTS A
RISK OF TRAINING CONVECTION. GIVEN THE EXPECTED RAINFALL
RATES...EXTREMELY HVY RAINFALL AMTS WILL BE POSSIBLE.

CONSEQUENTLY...THE POTENTIAL EXISTS FOR A HIGH-IMPACT FLASH FLOOD
EVENT THIS EVENING AND ESPECIALLY WITH LOCALLY WET ANTECEDENT SOIL
CONDITIONS.

ORRISON

ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN...DDC...

ATTN...RFC...ABRFC...LMRFC...MBRFC...

LAT...LON   38639697 38999579 38889435 38389357 37419322 36809343
            36449440 36289561 36379718 36589886 36909998 37459999
            38129895 38639697