MESOSCALE PRECIPITATION DISCUSSION 0105
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
647 PM EDT TUE MAY 19 2015
 
AREAS AFFECTED...NRN TEXAS INTO SRN OKLAHOMAH 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 192246Z - 200445Z
 
SUMMARY...EXPANDING COVERAGE OF HEAVY RAIN INTO THE OVERNIGHT
HOURS IS EXPECTED TO LEAD TO AN INCREASED FLASH FLOOD THREAT.
THERE IS GOOD MODEL AGREEMENT AMONG A MAJORITY OF THE HI-RES
MODELS FOR 3-6 INCHES ACROSS PORTIONS OF SRN AND CNTRL OKLAHOMA BY
05Z.

DISCUSSION...22Z OBSERVATIONS PLACED A WELL DEFINED EAST-WEST
ORIENTED STATIONARY FRONT ACROSS S-CNTRL OKLAHOMA WITH A SIMILARLY
ORIENTED OUTFLOW BOUNDARY EXTENDING NEAR THE RED RIVER. LARGE CAPE
VALUES OF 3000+ JK/G WERE IN PLACE ACROSS MUCH OF TEXAS ACCORDING
TO THE LATEST GOES SOUNDER AND SPC MESOANALYSIS PAGE WITH
PRECIPITABLE WATER VALUES NEAR THE 99TH PERCENTILE ACROSS CNTRL
TEXAS WITH SSWLY FLO2 OF ABOUT 30 KTS BETWEEN 850-700 MB FEEDING
ATOP THESE BOUNDARIES. REGIONAL RADAR IMAGERY DEPICTED INCREASING
COVERAGE OF CONVECTION IN THE VICINITY OF NWRN TEXAS AND SWRN
OKLAHOMA UNDER THE PRESENCE OF MODERATELY DIFFLUENT UPPER LEVEL
FLOW.

THERE IS GOOD AGREEMENT AMONG THE HI-RES MODELS...MOST NOTABLY
WITH RECENT RUNS OF THE HRRR...EXPERIMENTAL HRRR AND 12Z NSSL WRF
CONCERNING THE EVOLUTION OF HEAVY RAINFALL INTO THE EARLY
OVERNIGHT HOURS. AS A NEGATIVELY TILTED UPPER TROUGH AXIS
CONTINUES TO LIFT NEWD ACROSS THE CNTRL PLAINS OVER THE NEXT FEW
HOURS...30+ KTS OF 850-700 MB FLOW WILL FOCUS PRIMARILY ACROSS THE
RED RIVER INTO CNTRL AND ERN OKLAHOMA. THIS SETUP WILL CONTINUE TO
FEED MOISTURE/INSTABILITY TOWARD THE NORTH...OVERRUNNING THE
EFFECTIVE FRONT...AND ALLOWING HEAVY RAIN TO TRANSLATE TOWARD THE
EAST WITH REGENERATION OF HEAVY RAINFALL ACROSS NORTHWEST TEXAS
AND SRN OKLAHOMA. STREAKS OF RAINFALL WITH ADDITIONAL TOTALS OF
3-6 INCHES ARE EXPECTED ACROSS THE THREAT AREA.

OTTO

ATTN...WFO...AMA...FWD...LUB...OUN...SJT...TSA...

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

LAT...LON   36469603 35419561 34309594 33179808 33340031 
            34590044 35439941 36079815