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Tropical Storm Harvey Discussion Number  35
NWS National Hurricane Center Miami FL       AL092017
1000 PM CDT Mon Aug 28 2017

The center of Harvey has been moving east-southeastward over the
extreme western Gulf of Mexico this evening.  Although there is no
deep convection near the center of Harvey, thunderstorm activity has
continued to increase well north of the center, along the immediate
northwest Gulf Coast and has spread inland over the Greater Houston
area, worsening the catastrophic flooding situation.  Another band
of heavy rainfall is moving inland over portions of southern and
southwestern Louisiana.  Widespread rainfall totals of 30 to 36
inches have been observed in southeastern Texas and the Houston
Metropolitan Area.  Storm totals could reach 50 inches in some
locations, which would be historic for the area.

A NOAA National Ocean Service observing site near Matagorda Bay has
continued to report sustained tropical-storm-force winds this
evening, and data from this and other nearby stations still support
an initial intensity of 40 kt.  Given the current structure of the
cyclone and the lack of convection near the center, little change
in strength is expected while Harvey moves over the northwestern
Gulf of Mexico.  After landfall in about 36 hours, gradual weakening
should occur as the circulation moves farther inland.

Harvey has been moving east-southeastward or 120/3 kt.  The storm
is forecast to turn northeastward, then north-northeastward over
the next couple of days as a ridge to the northwest of the system
weakens and Harvey is steered around the western side of a ridge
over the eastern Gulf of Mexico.  The track guidance has shifted
slightly eastward and the new NHC track has been adjusted in that
direction.


Key Messages:

1. Ongoing catastrophic and life-threatening flooding will continue
across southeastern Texas.  Additional rainfall accumulations of 10
to 20 inches are expected across the upper Texas coast, with
isolated storm totals as high as 50 inches.  Please heed the advice
of local officials.  Do not attempt to travel if you are in a safe
place, and do not drive into flooded roadways.  Refer to products
from your local National Weather Service office and the NOAA Weather
Prediction Center for more information on the flooding hazard.  A
summary of rainfall totals compiled by the Weather Prediction Center
can be found at: www.wpc.ncep.noaa.gov/discussions/nfdscc1.html

2. The flood threat has spreading farther east into Louisiana.
Additional rainfall amounts of 10 to 20 inches are expected in
southwestern Louisiana, with rainfall amounts of 5 to 15 inches
expected in south-central Louisiana. Rainfall amounts of 5 to 10
inches are expected in southeast Louisiana and coastal Mississippi
and Alabama.  Please heed the advice of local officials and refer to
products from your local National Weather Service office and the
NOAA Weather Prediction Center for more information on the flooding
hazard in these areas.

3. While Tropical Storm Warnings have been extended eastward along
the coast of Louisiana and a Storm Surge Watch has been issued, the
impacts of winds and storm surge are expected to be secondary
compared to that of the rains.


FORECAST POSITIONS AND MAX WINDS

INIT  29/0300Z 28.2N  95.3W   40 KT  45 MPH
 12H  29/1200Z 28.1N  95.0W   40 KT  45 MPH
 24H  30/0000Z 28.5N  94.5W   40 KT  45 MPH
 36H  30/1200Z 29.5N  94.0W   40 KT  45 MPH
 48H  31/0000Z 30.7N  93.4W   35 KT  40 MPH...INLAND
 72H  01/0000Z 33.4N  91.9W   30 KT  35 MPH...INLAND
 96H  02/0000Z 35.5N  90.0W   25 KT  30 MPH...INLAND
120H  03/0000Z 38.0N  86.5W   20 KT  25 MPH...POST-TROP/INLAND

$$
Forecaster Brown

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