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Tropical Storm HARVEY


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Tropical Storm Harvey Discussion Number  33
NWS National Hurricane Center Miami FL       AL092017
1000 AM CDT Mon Aug 28 2017

Radar and surface data indicate that the center of Harvey is near
or just off the Texas coast south of Matagorda.  The system
currently has only disorganized convection near the center, with the
primary deep convection in a band well to the east of the center.
The initial intensity remains 35 kt based on a minimum central
pressure around 997 mb and the assumption that stronger winds aloft
seen on the Houston WSR-88D are mixing down to the surface in the
stronger bands.

While the convection is currently poorly organized, very heavy rains
and life-threatening flash flooding continue over southeastern Texas
and southwestern Louisiana.  There have been reports of 2-day
rainfall totals of close to 30 inches in the Greater Houston area.
With the additional rains that are expected over the next several
days, rainfall totals could reach 50 inches in some locations, which
would be historic for the area.

Due to the current structure, a dry slot seen in water vapor
imagery over the southern part of the circulation, and the lack of
intensification shown by the intensity guidance, only slight
strengthening is anticipated while Harvey remains over the Gulf of
Mexico.  The new intensity forecast is an update of the previous
one.

Radar and surface observations indicate that the center is moving
slowly southeastward, or 125/4 kt.  A mid-level trough dropping
into the Ohio Valley should cause Harvey to turn toward the east
and northeast and move back over land in a couple of days.  There
is little change to the forecast track from the previous advisory,
and the new track remains close to the dynamical model consensus.


Key Messages:

1. Ongoing catastrophic and life-threatening flooding will continue
across southeastern Texas.  Additional rainfall accumulations of 15
to 25 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 is spreading farther east into Louisiana.
Additional rainfall amounts of 15 to 25 inches are expected in
southwestern Louisiana, with rainfall amounts of 5 to 15 inches
expected in south-central Louisiana and 5 to 10 inches in
southeastern Louisiana. 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 Watches and Warnings have been extended
eastward to the coast of Louisiana, the impacts of winds and storm
surge are expected to be secondary compared to that of the rains.


FORECAST POSITIONS AND MAX WINDS

INIT  28/1500Z 28.5N  96.0W   35 KT  40 MPH
 12H  29/0000Z 28.1N  95.7W   35 KT  40 MPH
 24H  29/1200Z 28.1N  95.3W   35 KT  40 MPH
 36H  30/0000Z 28.5N  94.8W   40 KT  45 MPH
 48H  30/1200Z 29.4N  94.4W   40 KT  45 MPH
 72H  31/1200Z 31.5N  93.5W   35 KT  40 MPH...INLAND
 96H  01/1200Z 33.5N  92.0W   30 KT  35 MPH...INLAND
120H  02/1200Z 35.5N  90.5W   20 KT  25 MPH...INLAND

$$
Forecaster Beven

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