Graphic for MPD #0752
MESOSCALE PRECIPITATION DISCUSSION 0752
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1157 AM EDT MON AUG 28 2017

AREAS AFFECTED...UPPER TX COAST...EXT SOUTHWEST LA

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

VALID 281600Z - 282100Z

SUMMARY...STEADILY INCREASING CONVECTION NORTHEAST OF HARVEY'S
CENTER ALONG DEFORMATION ZONE. ADDITIONAL 3-6" ADDITIONAL TOTALS
LIKELY TO CONTINUE FLASH FLOODING. 

DISCUSSION...CENTER OF HARVEY HAS SLIPPED JUST OFF THE TX COAST SE
OF MATAGORDA BAY.  WHILE EXPERIMENTAL GOES-16 6.9UM WV SUGGESTS
MID-LEVEL CENTER REMAINS JUST ASHORE TO THE NORTHEAST OVER E
MATAGORDA/SW BRAZORIA COUNTY DENOTING A SLIGHT NORTHEAST TILT TO
THE SYSTEM.  7.3UM WV ALSO DEPICTS STARK DRY CONVEYOR/SLOT
COVERING SE TX INTO SW LA.  THE MULTIPLE-WV SUITE ALSO SUGGESTS
THE NARROWING OF THE DEFORMATION ZONE/TROWAL ON THE NW SIDE OF THE
CIRCULATION.  OVERALL THIS SUGGESTS CONVECTION NEAR JUST NORTHEAST
OF THE CENTER WILL BE NEARLY STATIONARY WHILE ALSO SUPPORTED BY
REMAINING MID-LEVEL MOISTURE TRANSPORT FROM THE WARM CONVEYOR
BELT. AS SUCH CONVECTIVE AREAS HAVE FORMED WITH SHALLOW BUT
PERSISTENT BACKBUILDING ACROSS SW BRAZORIA AND NE BRAZORIA/S
HARRIS COUNTIES...DEEP MOISTURE AND WARM CLOUD PROCESSES SUPPORT
RAIN RATES OF 1.5"/HR OVER SATURATED SOILS PROLONGING THE HISTORIC
FLOODING CONDITIONS IN THE REGION.

FURTHER EAST IN THE DRY SLOT...CLEARING IS DEPICTED IN .6UM
VISIBLE IMAGERY ACROSS SE TX EXTENDING SOUTHWARD INTO THE GULF. 
THIS IS PROVIDING INCREASED INSOLATION AND STEADILY INCREASING
INSTABILITY.  EXPECTATION IS FOR CONVECTIVE DEVELOPMENT TO BEGIN
TO INCREASE OVER THE NEXT FEW HOURS ALONG THE COAST WHERE
FRICTIONAL CONVERGENCE IS MAXIMIZED...AS WELL AS DEEPER MST
CONVERGENCE ALONG THE AFOREMENTIONED SHARPENING DEFORMATION ZONE.
THE COMBINED AFFECTS WILL ALLOW FOR FAIRLY STATIONARY/TRAINING
CELLS TO DEVELOP WHILE ALSO SUPPORTING UPSTREAM REDEVELOPMENT
THROUGH THE EARLY AFTERNOON HOURS.  RATES WILL ALSO STEADILY
INCREASE WITH CONVECTIVE VIGOR TOWARD 18-20Z SUPPORTING RATES OF
2.5-3.5"/HR AND TOTALS PARTICULARLY ALONG COAST SOUTH OF I-10 TO
EXCEED 3" WITH LOCALIZED TOTALS OF 6" OR EVEN HIGHER POSSIBLE. 
THIS IS IN LINE WITH THE 12Z NAM-CONEST AND 00Z ARW. 

GALLINA

ATTN...WFO...HGX...LCH...

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

LAT...LON   30759413 30559380 30219336 29829311 29629336
            29379437 28709560 28579609 29169665 29829626
            30279556 30589483


Last Updated: 1157 AM EDT MON AUG 28 2017