MESOSCALE PRECIPITATION DISCUSSION 0202
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
955 PM EDT FRI JUN 12 2015
 
AREAS AFFECTED...WESTERN AND NORTHERN TX...CENTRAL AND NORTHERN OK 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 130150Z - 130615Z
 
SUMMARY...SLOW-MOVING SHOWERS AND THUNDERSTORMS TO CONTINUE WELL
INTO THE OVERNIGHT HOURS WITH FLASH FLOODING POSSIBLE.

DISCUSSION...THE LATEST SATELLITE AND RADAR IMAGERY SHOWS AN
ELONGATED AXIS OF HEAVY SHOWERS AND THUNDERSTORMS FROM WEST TEXAS
NORTHEAST INTO WEST-CENTRAL AND NORTHERN OK. THIS ACTIVITY REMAINS
FOCUSED ALONG AND ADJACENT A STATIONARY FRONTAL ZONE WHERE THERE
HAS BEEN A WELL-DEFINED AXIS OF STRONGER LOW LEVEL CONVERGENCE
THROUGHOUT THE EVENING. THE CONVECTION IS ALSO BEING INFLUENCED BY
THE SLOWLY EJECTING SHORTWAVE TROUGH THAT IS ADVANCING EAST ACROSS
THE CENTRAL PLAINS AT THIS TIME. DIVERGENT FLOW/FORCING ALOFT
CONTINUES TO INTERACT WITH THE FRONT AND A POOL OF RATHER DEEP
MOISTURE AND INSTABILITY. IN FACT...THE LATEST GOES-SOUNDER PWATS
ARE ON THE ORDER OF 1.5 TO 1.75 INCHES...WITH MUCAPE VALUES CLOSE
TO 2000 J/KG.

OVER THE NEXT FEW HOURS THE CONVECTION SHOULD TEND TO REMAIN
ORGANIZED ALONG THE FRONT...GIVEN A FAVORABLE AXIS OF DEEPER
MOISTURE CONVERGENCE AND A MODESTLY INCREASING LOW LEVEL JET. THE
LOSS OF DIURNAL HEATING WILL ALLOW INSTABILITY PARAMETERS TO
WEAKEN WITH TIME...BUT SUFFICIENT LOW AND MID LEVEL FORCING SHOULD
ALLOW CONVECTION TO PERSIST THROUGH THE 06Z TIME FRAME. STORM
MOTION IS RATHER WEAK AND THIS IS CONTRIBUTING TO HEAVY RAINFALL
TOTALS GIVEN SLOW CELL MOTION. AREAS OF BACKBUILDING AND TRAINING
CONVECTION WILL REMAIN POSSIBLE ALONG THE FRONT...AND THIS WILL
FAVOR EXCESSIVE RAINFALL AMOUNTS WITH ADDITIONAL AMOUNTS OF 2 TO 4
INCHES AND LOCALLY HEAVIER AMOUNTS THROUGH 06Z. THE LATEST HRRR
FAVORS THIS SCENARIO AND CONSEQUENTLY THERE WILL BE A THREAT FOR
FLASH FLOODING.

ORRISON

ATTN...WFO...AMA...FWD...ICT...LUB...MAF...OUN...SGF...SJT...

ATTN...RFC...ABRFC...WGRFC...

LAT...LON   37269576 37109472 36779471 36459477 36069525 
            35629621 34759721 33669824 33059928 32700070 
            32710196 33100232 33640228 34410114 35719988 
            36359906 36959759