MESOSCALE PRECIPITATION DISCUSSION 0107
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
403 AM EDT WED MAY 20 2015
 
AREAS AFFECTED...NORTHERN TX/SOUTHERN OK/WESTERN AR... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 200802Z - 201232Z
 
SUMMARY...FLASH FLOODING REMAINS LIKELY ALONG THE RED RIVER AND
EXTENDING EASTWARD INTO SECTIONS OF AR. PERSISTENT CONVECTION
CONTINUES ACROSS SOUTHERN OK/NORTHERN TX/WESTERN AR WHERE HOURLY
RAINFALL RATES HAVE REACHED 2 TO 3 INCHES. EXPECT THIS ACTIVITY TO
MAINTAIN ITS STRENGTH THROUGH AT LEAST 12Z.

DISCUSSION...07Z SURFACE OBSERVATIONS ACROSS THE REGION SHOWED THE
PARENT COLD FRONT NOSED SLOWLY TOWARD THE SOUTH WITH CONVECTIVE
OUTFLOW SPREAD ALONG MUCH OF THE RED RIVER. ACCORDING TO THE 07Z
RAP OBJECTIVE ANALYSIS...THE INFLOW AIR REMAINS QUITE BUOYANT AND
UNCAPPED WITH MLCAPE VALUES IN THE 1000 TO 1500 J/KG RANGE. THIS
AXIS OF INSTABILITY EXTENDS EASTWARD TOWARD THE TX/OK/AR BORDER.
ADDITIONALLY...THE 925/850-MB WINDS HAVE SHOWN VERY LITTLE CHANGE
IN STRENGTH WITH VAD WIND PROFILER DATA SUGGESTING WIND SPEEDS
REACHING 35 TO 45 KNOTS ACROSS CENTRAL TX.

RADAR IMAGERY EARLY THIS MORNING SHOWED THE AXIS OF CONVECTION HAS
EVOLVED INTO A QLCS WITH MULTIPLE CELL MERGERS NOTED.
FURTHER...THE MOIST/UNSTABLE AIR MASS TO THE SOUTH HAS FOSTERED
THE DEVELOPMENT OF FEEDER CELLS WHICH HAVE BECOME INGESTED INTO
THE PROMINENT LINE. THIS SYSTEM ALREADY HAS A HISTORY OF
WIDESPREAD FLASH FLOODING WITH THE MOST RECENT REPORTS COMING OUT
OF WICHITA FALLS...TX. SUCH CONDITIONS WILL PERSIST THROUGH AT
LEAST 12Z.

THE 00Z HRW-ARW AND HRW-NMM-B SEEM TO BE HANDLING THE CONVECTION
WELL ALTHOUGH THEY DO NOT APPEAR TO CARRY THE ACTIVITY FAR ENOUGH
EAST. THE 07Z HRRR INDICATES THE HEAVIEST RAINFALL AMOUNTS IN THE
NEXT FEW HOURS SHOULD BE RIGHT ALONG THE RED RIVER AND INTO
SOUTHEASTERN OK WHERE 2 TO 3 INCH AMOUNTS ARE POSSIBLE IN A SHORT
PERIOD OF TIME. WILL LET DAY SHIFT RE-EVALUATE THE SITUATION ONCE
THIS MPD EXPIRES. 


RUBIN-OSTER

ATTN...WFO...FWD...LUB...LZK...OUN...SHV...SJT...TSA...

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

LAT...LON   35979311 35589205 34739162 33629249 32799436 
            32359626 32629927 33440004 34109992 34389938 
            34389808 34479647 35009516 35579434 35939387