Graphic for MPD #0086

MESOSCALE PRECIPITATION DISCUSSION 0086
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
618 PM EDT WED MAR 29 2017

AREAS AFFECTED...FAR SOUTHEAST TX/SOUTHWESTERN TO CENTRAL LA...

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 292217Z - 300217Z

SUMMARY...UPSTREAM CONVECTION AHEAD OF AN EASTWARD PROGRESSING
DRYLINE HAS A HISTORY OF DROPPING HEAVY RAINFALL WITH HOURLY RATES
IN EXCESS OF 2 INCHES. AS CLOUD TOPS CONTINUE TO COOL AND THE
LOW-LEVEL MOIST INFLOW INCREASES IN STRENGTH...EXPECT THE
POTENTIAL FOR LOCALIZED FLASH FLOOD ISSUES INTO SOUTHWESTERN TO
CENTRAL LA.

DISCUSSION...MULTIPLE SUPERCELLS EXITING OUT OF SOUTHEAST TX HAVE
A HISTORY OF PRODUCING POCKETS OF SEVERE WEATHER ACCOMPANIED WITH
COPIOUS RAINFALL. HOURLY MESONET DATA ACROSS SOUTHERN HARRIS
COUNTY...JUST NORTH OF GALVESTON TX...INDICATED AMOUNTS EXCEEDING
2 INCHES. MULTIPLE OBSERVATIONS SUPPORT SUCH AMOUNTS WITH EVEN A
FEW ISOLATED REPORTS NEARING 2.50 INCHES. WHILE THERE HAVE BEEN
HYDROLOGIC-RELATED LOCAL STORM REPORTS WITH THESE CELLS...THESE
ROBUST RAINFALL AMOUNTS WILL LIKELY SPREAD DOWNSTREAM INTO
SOUTHWESTERN LA.

RECENT RUNS OF THE RAP INDICATE A SLIGHT INCREASE IN THE
PRECIPITABLE WATER VALUES WITH AN ACCOMPANYING UPTICK IN STRENGTH
OF THE LOW-LEVEL FLOW. THIS COMBINATION IN CONJUNCTION WITH AMPLE
BUOYANCY...SURFACE-BASED INSTABILITY IN EXCESS OF 1500
J/KG...SHOULD HELP KEEP THIS COMPLEX RATHER ORGANIZED. THERE WILL
REMAIN A TENDENCY FOR THE SOUTHWESTERN FLANK OF THE CONVECTION TO
HANG UP AND/OR REMAINING SLOWER MOVING WHICH COULD INCREASE THE
THREAT FOR ISOLATED FLASH FLOODING. THE LAST 5 RUNS OF THE HRRR
HAVE BEEN FAIRLY CONSISTENT IN PAINTING HEAVY RAINFALL IN A
SOUTHWEST/NORTHEAST FASHION ACROSS THE MPD AREA. GIVEN THIS
PERSISTENCE COUPLED WITH ONGOING RADAR/SATELLITE TRENDS...FEEL
CONFIDENT IN THIS COMPLEX MAINTAINING A HEALTHY SIGNATURE INTO THE
LATER EVENING HOURS.

RUBIN-OSTER

ATTN...WFO...HGX...JAN...LCH...LIX...SHV...

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

LAT...LON   31599309 31449169 30409148 29649222 28759277
            28289354 28389447 29239468 30859395


Last Updated: 618 PM EDT WED MAR 29 2017