MESOSCALE PRECIPITATION DISCUSSION 0435
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
231 AM EDT MON AUG 10 2015
 
AREAS AFFECTED...FAR SOUTHEAST KS...SOUTHERN MO...FAR NORTHEAST
AR....FAR WESTERN TN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 100625Z - 101225Z
 
SUMMARY...TRAINING CONVECTION CONTINUES ACROSS SOUTHERN MO...WITH
CONVECTIVE INITIATION UNDERWAY UPSTREAM ACROSS SOUTHEAST KS AND
SOUTHWEST MO. FLASH FLOODING IS LIKELY.

DISCUSSION...VERY COLD-TOPPED CONVECTION CONTINUES TO
DEVELOP...BACKBUILD AND TRAIN OVER THE SAME AREA ACROSS SOUTHERN
MO IN VICINITY OF A SLOWLY SOUTHWARD SAGGING OUTFLOW BOUNDARY.
MEANWHILE..AREA VWPS SUGGEST INCREASINGLY CONFLUENT LOW LEVEL FLOW
IN THE 925MB TO 850 MB LAYER FROM SOUTHEAST KS THROUGH SOUTHERN
MO. THIS IS OCCURRING AS A WEAK AREA OF LOW PRESSURE IS MOVING
EAST INTO SOUTHWEST MO ALONG A NEARLY STATIONARY FRONTAL ZONE.

LARGER SCALE FORCING IS TENDING TO BE QUITE MODEST...BUT THE
LATEST GOES-RGB AIRMASS IMAGERY DOES SUGGEST SOME SUBTLE VORT
ENERGY MOVING EAST ACROSS KS WHICH WILL BE MOVING INTO WESTERN MO
OVER THE NEXT FEW HOURS. THIS COUPLED WITH THE WEAK SURFACE
WAVE...CONFLUENT LOW LEVEL FLOW...AND AN OTHERWISE VERY MOIST AND
UNSTABLE ATMOSPHERE SHOULD ALLOW FOR CONVECTION TO INITIATE AND
EXPAND IN COVERAGE OVER THE NEXT COUPLE OF HOURS. ALREADY
CONVECTION IS SEEN DEVELOPING OVER SOUTHEAST KS AND SOUTHWEST
MO...AND THIS CONVECTION WILL EXPAND EAST AND JOIN UP WITH THE
WESTERN EDGE OF THE TRAINING CONVECTIVE BAND ALREADY IMPACTING
SOUTHEAST MO. THUS...THERE WILL LIKELY BE A W/E ORIENTED BAND OF
TRAINING CONVECTION IMPACTING A LARGE PORTION OF SOUTHERN MO IN A
COUPLE OF HOURS WHERE EXTREMELY HEAVY RAINFALL RATES/AMOUNTS ARE
GOING TO BE EXPECTED. IN TIME...SUFFICIENT COLD POOL GENERATION IS
EXPECTED SUCH THAT THE EASTERN FLANK OF THE TRAINING CONVECTION
SINK SOUTH INTO NORTHEAST AR AND WESTERN TN.

THE LATEST HIRES GUIDANCE...INCLUDING CONSECUTIVE RUNS OF THE
HRRR...ALONG WITH THE 00Z ARW AND 00Z NMMB FAVOR THIS SET-UP. THE
PWAT ENVIRONMENT IS VERY IMPRESSIVE WITH TPW VALUES LOCALLY AROUND
2.25 INCHES. LAYERED PWAT ANALYSIS SHOWS A CONVERGENCE OF MID AND
HIGH LEVEL MOISTURE OVER SOUTHEAST KS AND SOUTHERN MO...SO THE
CONVECTIVE CORES ARE EXPECTED TO BE HIGHLY EFFICIENT WHICH COUPLED
WITH OVERSHOOTING TOPS WILL FOSTER EXTREMELY HIGH RAINFALL RATES
THAT COULD APPROACH 3 INCHES/HR.

RAINFALL AMOUNTS IN EXCESS OF 5 INCHES ARE EXPECTED LOCALLY...AND
THIS WILL RESULT IN POTENTIALLY LIFE-THREATENING FLASH FLOODING
THIS MORNING.

ORRISON

ATTN...WFO...EAX...ICT...LSX...LZK...MEG...PAH...SGF...TOP...

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

LAT...LON   38179281 38039118 38049086 37648986 36808908 
            36148897 35468915 35229000 35539103 36539263 
            36959403 37219586 37609615 37939587 38129459