[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 012359
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT THU SEP 01 2016

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...

Hurricane Hermine is centered near 29.1N 84.8W at 02/0000 UTC or
about 40 nm south-southeast of Apalachicola, Florida and about
90 nm west of Cedar Key, Florida moving north-northeast at 12
kt. Estimated minimum central pressure is 983 mb. Maximum
sustained wind speed is 70 kt with gusts to 85 kt. Scattered
moderate to strong convection is north of 27N east of 87W to
inland over Florida. Scattered moderate with clusters of
isolated strong convection covers the area east of a line from
27N86W to 24N88W then southeast to the western tip of Cuba
including most of the Florida peninsula, west Cuba, and the
Straits of Florida. See latest NHC Intermediate Public Advisory
under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full
Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/
WTNT24KNHC for more details.

Hurricane Gaston is centered near 38.3N 37.3W at 02/0000 UTC or
about 405 nm west of Faial Island in the central Azores and
about 480 Nm west of Lajes Air Base in the Azores moving east-
northeast at 22 kt. Estimated minimum central pressure is 984
mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt.
Scattered moderate to isolated strong convection is within 75 nm
of a line from 37N38W 39N38W to 41N36W. See latest NHC Forecast/
Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for
more details.

...TROPICAL WAVES...

Tropical wave in the central Atlantic extends along 36W/37W from
9N-20N moving west near 20 kt over the past 24 hours. Wave
coincides with a well defined global model, 700 mb trough and is
embedded within a surge of deep moisture as seen on the Total
Precipitable Water imagery. Small clusters of isolated moderate
convection dot the area from 13N-17N between 39W-42W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends across Africa into the east Tropical
Atlantic near 15N17W along 11N27W 11N39W to 10N43W where the
ITCZ begins and continues along 10N52W to near 11N59W. Clusters
of scattered moderate to isolated strong convection are from 5N-
11N east of 34W to the coast of west Africa and from 8N-11N
between 40W-48W.

...DISCUSSION...

GULF OF MEXICO...

The primary concern again this evening is Hurricane Hermine.
Hermine became a hurricane this afternoon at 01/1855 UTC based
on information from the Air Force Hurricane Hunter Aircraft.
Hurricane Hermina is moving across the northeast Gulf of Mexico.
The activity over the east Gulf of Mexico is due to Hurricane
Hermine. See Special Features above. A broad upper trough covers
the east CONUS dipping south over the west Gulf with a surface
trough extending from 25N87W to 22N95W. Scattered showers and
isolated thunderstorms are within 45 nm of the surface trough.
Isolated showers and thunderstorms dot the area from 23N-26N
between 91W-97W. Scattered to numerous showers and isolated
thunderstorms are across the Bay of Campeche south of 20N west
of 93W. The forecast track for Hermine takes the system
northeastward across the western Florida panhandle overnight
tonight then tracks along the coastal plains of the Carolinas
Friday night and Saturday. Winds and seas will decrease over the
Gulf Friday through Saturday.

CARIBBEAN SEA...

The upper ridge associated with Hermine covers the Caribbean
west of 79W with a second upper ridge anchored in the west
Atlantic covering the east Caribbean east of 70W. Wedge between
these upper ridges is an elongated upper low centered along the
southwest coast of Haiti near 18N74W and extends south across
the Caribbean to the coast of Colombia. The northerly upper
level flow over the west Caribbean combined with the southerly
surface flow is generating isolated showers and thunderstorms
dotting the west Caribbean north of 15N west of 77W. A surface
trough extends from the central Atlantic near 23N58W across the
northern Leeward Islands to 16N63W generating isolated showers
and possible isolated thunderstorms over the northern Leeward
Islands north of 17N to Puerto Rico. A second surface trough is
east of the Windward Islands along 60W from 10N-16N generating
scattered showers and isolated thunderstorms from 10N-17N
between 58W-63W. The surface trough east of the Windward Islands
will move into the east Caribbean tonight then continue westward
into the weekend. Fresh to strong trade winds are across the
south-central Caribbean through Friday. A tropical wave will
enter the east Caribbean late Saturday.

...HISPANIOLA...

Currently skies are mostly clear across the island. An elongated
upper low is centered along the southwest coast of Haiti near
18N74W and extends south across the Caribbean to the coast of
Colombia. The upper low will continue to track westward becoming
an open trough Friday night. The surface trough over the Leeward
Islands will continue moving westward bringing moisture to the
island Friday giving the island showers and thunderstorms Friday
and Saturday.

ATLANTIC OCEAN...

Hurricane Gaston continues moving northeast toward the northern
Azores Islands. See Special features above. Scattered to numerous
showers and isolated thunderstorms generated by Hurricane
Hermine are north of 26N west of 79W to inland over Florida and
southeast Georgia. The upper trough over the east CONUS is
moving into the northwest Atlantic supporting a weak surface
trough that extends through 32N74W to 30N75W. An elongated upper
trough is in the central Atlantic extending from an upper low
east of the Lesser Antilles near 17N55W to 32N44W supporting a
surface trough that extends from 23N58W to 16N63W. This surface
trough is leading the edge of large area of Saharan dust and
dry air that extends east to off the coast of Africa near 20W
and is limiting shower activity associated with this surface
trough as well as the tropical wave. A second surface trough is
east of the Windward Islands along 60W from 10N-16N generating
scattered showers and isolated thunderstorms from 10N-17N
between 58W-63W. The remainder of the Atlantic is dominated by a
surface ridge that is anchored by a 1028 mb high over the Azores
and extends a ridge axis through 32N31W, south of Hurricane
Gaston, to a 1022 mb high near 29N47W continuing along 28N60W
then southwest to 24N77W. Hurricane Hermine is expected to track
inland along the southeast CONUS Friday into Saturday morning
before entering the northwest Atlantic later Saturday. Strong
southerly winds and high seas will develop over the west
Atlantic waters east of the northeast Florida through Friday
before shifting northward.

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

$$
PAW
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