[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 292359
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
759 PM EDT Tue Aug 29 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2315 UTC.

...SPECIAL FEATURES...

Tropical Storm Harvey is centered near 28.7N 93.9W at 30/0000 UTC
or about 74 nm S of Port Arthur, Texas moving E at 5 kt.
Estimated minimum central pressure is 994 mb. Maximum sustained
wind speed is 45 kt with gusts to 55 kt. Scattered moderate
convection is present within 210 NM in the N quadrant of the
center over the E Texas and extreme western Louisiana coasts. WSR-
88D from Houston, TX indicates heavy rainfall from the Sabine
River to High Island, TX extending over the Houston metro area.
Scattered moderate convection is also occurring well E of the
center between SE Louisiana and the Florida Panhandle, from 27N-
32N between 86W-90W, due to a feeder band. See latest
Intermediate Public Advisory under AWIPS/WMO headers
MIATCPAT4/WTNT34 KNHC and the full Forecast/Advisory under
AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details.

Potential Tropical Cyclone Ten is centered near 36.0N 74.3W at
29/2100 UTC or about 74 nm NE of Cape Hatteras North Carolina
moving NE at 21 kt. Estimated minimum central pressure is 1003
mb. Maximum sustained winds are 40 kt with gusts to 50 kt.
Scattered moderate to isolated strong convection is well
displaced from the low level center and within 240 NM in the E
quadrant of the low over the Gulf Stream off the NC coast. The
system will continue to move away from the North Carolina coast
over the western Atlantic Ocean tonight. The system is forecast to
strengthen at sea and become a hurricane-force extra tropical low
over the northwestern Atlantic Ocean by Wednesday evening. The
system is not expected to become a tropical cyclone. See last
Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT5/
WTNT35 KNHC and the last full Forecast/Advisory under AWIPS/WMO
headers MIATCMAT5/WTNT25 KNHC for more details. Additional
information on this system can be found in high seas forecast
issued by the National Weather Service, under AWIPS header
NFDHSFAT1 and WMO header FZNT01 KWBC.

A tropical wave is over the E Atlantic associated with a 1008 mb
low that is located near 15N26W. The wave axis extends from
23N24W to the low to 10N25W, moving W at 15-20 kt. Widely
scattered moderate convection is from 10N-19N between 23W-32W.
A recent scatterometer pass indicated 20-25 KT winds within 180
nm in the N semicircle of the low. The wave is embedded in an area
of deep layer moisture as seen on TPW satellite imagery. This
system has become better organized since yesterday, and a tropical
depression could form from this system over the eastern Atlantic
during the next couple of days. Heavy rain is possible over
portions of the northwestern Cabo Verde Islands for a few more
hours. There is now a high chance for this system to become a
tropical cyclone during the next 48 hours.

...TROPICAL WAVES...

A tropical wave over the central Atlantic has an axis extending
from 24N43W to 17N43W to 11N41W, moving W at 10-15 kt. The wave
coincides with an amplified 700 mb trough in initial model wind
fields. TPW satellite imagery shows an area of modest deep layer
moisture located on the east side of the wave. Satellite imagery
also shows the presence of a large area of Saharan dust to the N
and W of the wave. Convection associated with the wave is limited
at this time.

A tropical wave over the E Caribbean extends from 22N68W to
10N70W moving W at 15-20 kt. The wave coincides with modest 700
mb troughing in initial model wind fields and curvature in the
most recent scatterometer pass. SSMI TPW imagery shows this wave
is embedded in an area of modest deep layer moisture. Widely
scattered moderate convection is from 15N-20N between 67W-73W to
include most of Hispaniola.

A tropical wave over the W Caribbean extends from 21N82W to
09N82W, moving W at 15 kt. The wave coincides with subtle 700 mb
troughing in initial model wind fields. TPW satellite imagery
shows this wave is embedded in an area of modest deep layer
moisture. Scattered moderate to isolated strong convection is W of
the wave axis over E Honduras, E Nicaragua, and N Costa Rica.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from 19N16W to 16N25W to 10N47W. The
ITCZ continues from 10N47W to 09N61W. Besides the convection
associated with the tropical waves, scattered moderate convection
is from 09N-13N between 54W-61W, to include portions of the
Windward Islands.

...DISCUSSION...

GULF OF MEXICO...

Tropical Storm Harvey has a fairly broad low-level exposed center
located over the Gulf of Mexico near 29N94W. Associated deep
convection is displaced NE of the center over the upper Texas and
extreme SW Louisiana coasts. Feeder bands east of the center
continue to produce isolated moderate convection over the north
central Gulf, Louisiana, Mississippi, Alabama and the western
Florida panhandle. Catastrophic inland flooding is forecast to
continue over Texas and Louisiana over the next few days. Of
interest, a preliminary report from a Texas rain gauge has broken
the Texas tropical cyclone rainfall record. A surface trough
traverses N Florida and the NE Gulf from 30N80W to 28N83W.
Divergent upper level winds are located east of the trough axis
over the Gulf of Mexico and Florida N of 26N. Harvey is expected
to drift slowly NE along the middle and upper coasts of Texas
through tonight, then move inland over SW Louisiana on Wednesday.

CARIBBEAN SEA...

Two tropical waves are moving across the Caribbean waters. See
the tropical waves section for additional details. The eastern
terminus of the E Pacific monsoon trough passes over Costa Rica,
and Panama and producing scattered moderate and isolated strong
convection over the Caribbean S of 13N and W of 76W. In the upper
levels, an upper level low is centered over the Yucatan Peninsula
near 19N87W enhancing showers over the Yucatan and Central
America.

...HISPANIOLA...

Widely scattered moderate convection is over the island due to a
tropical wave. Expect similar conditions through Wednesday.

ATLANTIC OCEAN...

The last advisory has been issued for Potential Tropical Cyclone
Ten. This system is now extra tropical and is forecast to rapidly
deepen over the next 24 hours. It merits continued watching. For
additional information please see Special Features section above.
Elsewhere, a broad 1027 mb high centered over the Azores near
39N28W ridges SW to another weaker 1020 mb high near 28N59W then
to the central Bahamas. Moderate to locally fresh trade winds
prevail south of the ridge west of 30W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Formosa
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