Graphic for MPD #0445

MESOSCALE PRECIPITATION DISCUSSION 0445
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
530 AM EDT WED JUL 05 2017

AREAS AFFECTED...RED RIVER VALLEY OF TX/OK INTO SOUTHERN AR

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 050930Z - 051430Z

SUMMARY...CONVECTION TRAINING OVER AREAS THAT RECEIVED HEAVY
RAINFALL EARLIER THIS MORNING IS EXPECTED TO PRODUCE FLASH
FLOODING OVER PORTIONS OF SOUTHEAST OK/NORTHEAST TX AND SOUTHWEST
AR THIS MORNING.

DISCUSSION...REGIONAL RADARS CONTINUE TO SHOW CONVECTION FIRING ON
THE SOUTH SIDE OF THE FRONT BOUNDARY EXTENDING ACROSS SOUTHERN OK.
THE LATEST EXPERIMENTAL GOES-16 CLEAN IR IMAGES SHOULD CLOUD TOPS
COOLING RAPIDLY OVER PORTIONS OF THE RED RIVER VALLEY...AS WELL AS
ACROSS FAR SOUTHEAST OK AND FAR SOUTHWEST AR. THE KTLX RADAR
SHOWED HOURLY RAINFALL RATES IN EXCESS OF 2.00 INCHES OVER CHOCTAW
COUNTY IN SOUTHEAST OK...WHILE CONVECTION OVER JEFFERSON COUNTY
HAD HOURLY RAINFALL RATES IN EXCESS OF 2.50 INCHES (THOUGH THE
JEFFERSON COUNTY RATES COULD BE HAIL CONTAMINATED).

THE CONVECTION CONTINUES TO DEVELOP AND INTENSITY IN AN AXIS OF
1500-2000 J/KG OF MUCAPE EXTENDING ACROSS SOUTHERN OK INTO CENTRAL
AND SOUTHERN AR...WHERE PRECIPITABLE WATER VALUES REMAIN NEAR 1.75
INCHES IN THIS AXIS. THE CONVECTION IS EXPECTED TO MOVE SLOWLY
EASTWARD WHERE THE LOW LEVEL CONVERGENCE FOCUSES THE BEST
INSTABILITY AND MOISTURE. SYNOPTIC SCALE ASCENT AHEAD OF A
VORTICITY MAXIMUM CROSSING NORTHERN OK SHOULD PROVIDE SUFFICIENT
LIFT TO MAINTAIN THE CONVECTIVE INTENSITY.

THERE REMAINS A STRONG HIGH RESOLUTION MODEL SIGNAL FOR HEAVY
RAINFALL ACROSS PORTIONS OF SOUTHEAST OK INTO SOUTHWEST AR...WHERE
THE 07Z HRRR SHOWED A MAXIMUM OF 6.00+ INCHES OF RAINFALL. BASED
ON THE RAINFALL RATES OBSERVED ON RADAR...LOCAL 6.00+ INCH AMOUNT
SEEM PLAUSIBLE... ESPECIALLY OVER SOUTHEAST OK. THE 00Z HREF
VERSION 2 SHOWED A GREATER THAN 80 PERCENT PROBABILITY OF 3.00+
INCHES IN SOUTHEAST OK...SO IT APPEARS AS THOUGH FLASH FLOODING
WILL OCCUR IN THIS AREA AT LEAST.

AS THE COLD POOL BECOMES BETTER ESTABLISHED AFTER 11Z...THERE IS A
HIGH RESOLUTION MODEL SIGNAL THAT THE CONVECTION COULD BECOME MORE
OUTFLOW DOMINATED...ALLOWING THE CONVECTION TO ACCELERATE
SOUTHEAST INTO NORTH TX. THE THREAT FOR FLASH FLOODING IS EXPECTED
WANE CLOSE TO 14Z...AS THE INSTABILITY IS EXHAUSTED.

HAYES

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

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

LAT...LON   35119339 34669193 33769201 33579347 33579347
            33299578 33459687 34399770 35089480


Last Updated: 530 AM EDT WED JUL 05 2017