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Tropical Depression Harvey Intermediate Advisory Number 12A
NWS National Hurricane Center Miami FL AL092017
100 PM CDT Wed Aug 23 2017
...HARVEY MOVING LITTLE BUT EXPECTED TO RESUME A NORTHWESTWARD
SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION
ABOUT 535 MI...860 KM SSE OF PORT OCONNOR TEXAS
ABOUT 470 MI...755 KM SE OF PORT MANSFIELD TEXAS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Watch is in effect for...
* Port Mansfield to High Island
A Hurricane Watch is in effect for...
* North of Port Mansfield to San Luis Pass
A Tropical Storm Watch is in effect for...
* Boca De Catan Mexico to Port Mansfield Texas
* North of San Luis Pass to High Island
A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
For a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
Interests in southwestern Louisiana should monitor the progress of
this system for possible watches this afternoon.
For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area outside
the United States, please monitor products issued by your national
DISCUSSION AND 48-HOUR OUTLOOK
At 100 PM CDT (1800 UTC), the center of Tropical Depression Harvey
was located near latitude 21.5 North, longitude 92.5 West. The
depression has been nearly stationary for the past few hours, but
is expected to resume a motion toward the northwest near 9 mph
(15 km/h) later today. A track toward the northwest or
north-northwest is expected for the next 48 hours. On the forecast
track, Harvey should be approaching the Texas coast late Friday.
Maximum sustained winds are near 35 mph (55 km/h) with higher
gusts. Some strengthening is forecast during the next 48 hours, and
Harvey could become a hurricane on Friday.
The estimated minimum central pressure is 1005 mb (29.68 inches).
HAZARDS AFFECTING LAND
RAINFALL: Harvey is expected to produce total rain accumulations of
10 to 15 inches with isolated maximum amounts of 20 inches over the
middle and upper Texas coast and southwest Louisiana through next
Tuesday, with heavy rainfall beginning as early as Friday morning.
Harvey is also expected to produce total rain accumulations of 3 to
9 inches in portions of south, central, and northeast Texas and the
rest of the lower Mississippi Valley. Rainfall from Harvey could
cause life-threatening flooding.
STORM SURGE: The combination of a dangerous storm surge and the tide
will cause normally dry areas near the coast to be flooded by rising
waters moving inland from the shoreline. The water is expected to
reach the following heights above ground if the peak surge occurs at
the time of high tide...
Port Mansfield to High Island...4 to 6 ft
The deepest water will occur along the immediate coast near and to
the northeast of the landfall location, where the surge will be
accompanied by large and destructive waves. Surge-related
flooding depends on the relative timing of the surge and the tidal
cycle, and can vary greatly over short distances. For information
specific to your area, please see products issued by your local
National Weather Service forecast office.
WIND: Hurricane conditions are possible within the hurricane watch
area by late Friday, with tropical storm conditions possible by
SURF: Swells generated by Harvey are likely to affect the Texas,
Louisiana, and northeast Mexico coasts by Friday. These swells are
likely to cause life-threatening surf and rip current conditions.
Please consult products from your local weather office.
Next complete advisory at 400 PM CDT.