MESOSCALE PRECIPITATION DISCUSSION 0403
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1256 AM EDT WED OCT 01 2014
 
AREAS AFFECTED...NORTHEAST KS...SOUTHEAST NEB...NORTHWEST
MO...SOUTHWEST IA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 010445Z - 010945Z
 
SUMMARY...FAVORABLE SET-UP FOR TRAINING CONVECTION OVERNIGHT WILL
FOSTER AN ENHANCED POTENTIAL FOR FLASH FLOODING.

DISCUSSION...THE LATEST SAT/RADAR TRENDS CONFIRM A SW/NE AXIS OF
HVY SHWRS/TSTMS WHICH HAS BEEN REPEATING AND TRAINING OVER THE
SAME AREA OVER THE LAST COUPLE OF HOURS INVOLVING NERN KS AND ESP
SERN NEB. THE ACTIVITY IS FOCUSED ALONG A VERY SLOW-MOVING FRONTAL
ZONE.

THE LATEST SFC OBS INDICATE THAT A WEAK AREA OF LOW PRESSURE HAS
FORMED OVER NERN KS NEAR THE NEB BORDER WHICH APPEARS TO BE
ENHANCING THE LOW LVL MOISTURE AND INSTABILITY TRANSPORT INTO THE
FRONT..AND THUS HELPING TO SUSTAIN THE ONGOING CONVECTION. HAVING
SAID THAT...THE INSTABILITY PARAMETERS ARE VERY MODEST WITH ONLY
500 TO 1000 J/KG OF MUCAPE. HOWEVER...THERE IS INCREASING LARGE
SCALE ASCENT THAT IS ARRIVING COURTESY OF A STRONG SHORTWAVE
TROUGH THAT IS SEEN DIGGING ACROSS ERN CO ATTM AS PER LATEST WV
IMAGERY. 

THE INCREASED FORCING/UVVS ALOFT AND AN EXPECTED INCREASE IN THE
LOW LVL JET UP THROUGH THE PLAINS INTO THE FRONTAL ZONE SHOULD
ALLOW ADDITIONAL CONVECTION TO DEVELOP THROUGH THE NIGHT...WITH A
HEIGHTENED RISK FOR TRAINING INVOF THE FRONT. PWATS ARE RELATIVELY
MODEST AT 1.25 TO 1.5 INCHES...BUT THE SW/NE ORIENTATION OF THE
CONVECTION AND REPEATING NATURE WILL NEVERTHELESS CONTRIBUTE TO A
THREAT FOR FLASH FLOODING OVERNIGHT...AND THIS IS SUPPORTED BY THE
18Z NAM-CONEST AND THE 12Z ARW/12Z NMMB SOLNS. LOCALLY 3 TO 6
INCHES OF RAIN IS EXPECTED WITH ISOLATED HEAVIER AMTS POSSIBLE
THROUGH THE NIGHT. WILL CONTINUE TO MONITOR.

ORRISON

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

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

LAT...LON   41919406 41629371 40879384 39919471 38619650 
            38239751 38559804 39079820 40059784 41249662 
            41909515