[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 031035
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
635 AM EDT SAT SEP 3 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 0600 UTC surface analysis and satellite imagery through
1030 UTC.

...SPECIAL FEATURES...

Tropical Storm Hermine is centered near 35.4N 76.5W at 03/0900
UTC or about 48 nm north of Cape Lookout, North Carolina and
about 52 nm west-northwest of Cape Hatteras, North Carolina
moving northeast at 18 kt. Estimated minimum central pressure is
997 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt.
Scattered moderate convection is from 32N-40W between 70W-75W. Please
see the 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.

Gaston has become a post-tropical system centered near 40.5N
26.9W at 03/0900 UTC or about 139 nm northeast of Faial Island in
the central Azores and about 104 nm north of Lajes Air Base in
the Azores moving east-northeast at 15 kt. Estimated minimum
central pressure is 1006 mb. Maximum sustained wind speed is 30
kt with gusts to 40 kt. No deep convection is noted with this
system. Please see the latest NHC Forecast/Advisory under the
AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details.

...TROPICAL WAVES...

A tropical wave is over the eastern Atlantic with an axis
extending from 22N28W to a 1010 mb low near 18N28W to 10N28W,
moving west at 10-15 kt. The northeast portion of this wave is
interacting with African dust which is inhibiting convection.
Isolated moderate convection prevails east of the wave axis
between 21W-27W while scattered moderate convection is where the
wave interacts with the Monsoon Trough mainly south of 12N between
24W-32W.

A tropical wave is moving across the central Atlantic with axis
extending from 20N48W to a 1009 mb low near 14N47W to 07N49W,
moving west at 15-20 kt. This wave is embedded in a moderately
moist environment with upper-level diffluence supporting scattered
moderate convection from 13N-18N between 45W-56W. This wave is
also generating a broad area of fresh to strong easterly winds
across the northern portion of it.

A tropical wave is moving across the south-central Caribbean with
axis extending from 16N76W into northern Colombia near 07N76W.
This feature is well depicted in model guidance and it is embedded
in an area of abundant moisture, as noted in TPW imagery.
Isolated moderate convection is observed along the southern
portion of the wave mainly south of 12N between 75W-79W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends across Africa into the east Tropical
Atlantic near 16N17W to the 1010 mb low and wave near 18N28W. The
boundary resumes near 12N25W to the 1009 mb low and wave near
14N49W. Aside from the convection associated with the tropical
waves, scattered moderate convection is from 04N-12N between 31W-
40W.

...DISCUSSION...

GULF OF MEXICO...

A surface trough extends across the Bay of Campeche from 24N95W
to 20N95W. Scattered moderate convection prevails near the
trough with stronger activity south of 20N between 93W-96W. A
thermal surface trough extends across the western portion of the
Yucatan Peninsula enhancing convection over the area. To the
east; a surface trough extends from 26N90W to 30N85W. Scattered
moderate convection prevails along this trough mainly between
83W-92W. Scatterometer data depicts gentle easterly winds over
the western half of the basin while gentle to moderate southerly
winds prevail east of 90W. During the next 24 hours: the trough
over the eastern Gulf will remain nearly stationary. The trough
over the southwestern Gulf will drift toward the Mexico coast with
ongoing convection.

CARIBBEAN SEA...

A tropical wave is moving across the central Caribbean. Please
refer to the section above for details. An upper-level low
prevails over the western Caribbean centered near 19N84W
supporting isolated convection west of 82W. Scatterometer data
depicts moderate to locally fresh trade winds across the basin.
Expect during the next 24 hours for the tropical wave to continue
moving west over the central/west Caribbean helping to bring an
increase in the trades over the south central Caribbean. Another
tropical wave will reach the eastern Caribbean by Saturday night
to Sunday with showers and thunderstorms. Fresh to strong easterly
winds will accompany the northern portion of this wave.

...HISPANIOLA...

The southern portion of a surface trough extends from the Atlantic
into the Windward Passage with isolated showers. Fair weather
prevails across the island at this time. A tropical wave will
help increasing easterly winds across the island along with
showers and thunderstorms by Sunday.

ATLANTIC OCEAN...

Post-tropical Gaston continues weakening as it nears the Azores
while Tropical Storm Hermine is just inland over the Carolinas.
Please refer to the section above for details. Two tropical waves
are moving across the basin. Please refer to the tropical waves
section above for details. Strong to near gale southwesterly winds
are north of 28N west of 75W as well as seas to 13 feet due to the
proximity of Hermine. To the east; a surface trough extends from
the Windward Passage to 23N72W. Isolated showers are observed
along this boundary. A surface ridge prevails across the remainder
of the basin anchored by three 1021 mb highs centered near
27N62N, 29N47W, and 31N34W. During the next 24 hours: Tropical
Storm Hermine will track northeastward north of our area. However,
fresh to strong winds and large seas will continue along the
extreme northwestern portion of our discussion waters through the
weekend. The tropical waves will continue to produce showers and
thunderstorms as they move westward across the central tropical
Atlantic through late Saturday.

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

$$

ERA
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