[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 300504
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
104 AM EDT Sun Sep 30 2018

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 0000 UTC surface analysis and satellite imagery through
0515 UTC.

...SPECIAL FEATURES...

Tropical Storm Leslie centered near 33.9N 52.0W at 30/0300 UTC
or 650 nm ENE of Bermuda moving SW at 5 kt. Estimated minimum
central pressure is 991 mb. Maximum sustained wind speed is 45
kt with gusts to 55 kt. A slow southwest or south-southwest track
is forecast for the next few days. Some gradual strengthening is
forecast during the next 72 hours. Scattered moderate convection
is from 31N-37N between 47W-53W. See the latest NHC forecast/
advisory under AWIPS/WMO headers MIATCPAT3/WTNT33 KNHC for more
details.

...TROPICAL WAVES...

A tropical wave has its axis along 32W from 02N-16N, moving W at
15-20 kt. Scattered showers are noted south of 10N, where the
wave meets the monsoon trough. This feature shows up well in the
Total Precipitable Water animation, and continues to have a sharp
trough at the surface as seen on the latest scatterometer pass.

A tropical wave has its axis along 52W from 05N-18N, moving W at
10-15 kt. The TPW imagery shows a moisture maximum E of the
wave's axis. There is a trough in the GFS 700 mb analyses, but
little signature is seen at the surface. Scattered showers are
developing within 75 nm to the east of the wave's axis between
10N-13N.

A tropical wave extends across the eastern Caribbean, with axis
along 72W and between 06N-20N, moving W at 15 kt. TPW imagery
depicts abundant moisture in the eastern Caribbean mainly east of
70W. Scattered moderate convection is from 11N-17N between 65W-
72W.

A tropical wave is moving across the Bay of Campeche along 93W
from 21N southward, moving W at 20 kt. A pronounced 700 mb trough
in the GFS analysis is noted with the wave, but little signature
of the wave is seen at the surface. The wave is enhancing
scattered showers within 180 nm of the wave's axis over S Mexico.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the eastern Atlantic near 16N17W and
continues SW to near 09N30W. The ITCZ extends from 06N35W to
04N40W to 08N51W, then resumes W of a tropical wave near 09N54W
and extends to the coast of South America near 09N61W. Scattered
moderate convection is noted along the monsoon trough from 09N-12N
between 21W-25W. Scattered moderate to isolated strong convection
is along the ITCZ from 04N-08N between 34W-40W.

...DISCUSSION...

GULF OF MEXICO...

A surface trough is over the E Gulf of Mexico from 29N83W to
25N84W. Scattered moderate convection is within 60 nm of the
trough. A surface trough is inland over the Yucatan Peninsula from
21N88W to 18N91W. Scattered moderate to isolated strong convection
is from 17N-20N between 90W-92W. Currently gentle to moderate
easterly surface winds are over the Gulf. Little change is
expected over the gulf waters during the next couple of days. Seas
will remain below 8 ft through Sunday.

Of note in the upper levels, an upper level low is centered over
central Texas near 31N100w. Upper level diffluence E of the
centered is producing scattered moderate to isolated strong
convection over the NW Gulf from 25N-31N between 89W-96W.

CARIBBEAN SEA...

Two tropical waves are moving across the basin. See the Tropical
Waves section above for details. The eastern extent of the E
Pacific monsoon trough extends over the Costa Rica and Panama
along 09N producing isolated moderate convection over the SW
Caribbean S of 13N. Recent scatterometer data indicate gentle to
moderate trades prevail across most of the basin except in the
vicinity of the tropical wave across the eastern Caribbean. Fresh
winds prevail mainly east of 66W. Large northerly swell associated
with Leslie will affect the tropical Atlantic waters tonight
through Sunday, building seas to 10-11 ft.

In the upper levels, an upper level low is centered N of E Cuba
near 22N76W. This low is producing scattered moderate convection S
of Cuba from 20N-21N between 77W-80W.

ATLANTIC OCEAN...

Two tropical waves are currently between the coast of Africa and
the Lesser Antilles. See the Tropical Waves section above for
details. A surface trough enters the forecast region near 30N44W
then continues SSW to 20N50W. Widely scattered moderate
convection is from 20N-35N between 40W-48W. This feature was
formerly associated with Leslie.

In the upper levels, the upper level low centered N of E Cuba
near 22N76W is producing scattered showers are from 20N-27N
between 70W-80W to include most of the Bahamas. Elsewhere, a
large upper level low is centered over the central Atlantic near
27N49W. There is a considerable amount of upper level diffluence E
of the center enhancing convection.

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

$$
Formosa
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