[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 151802
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
202 PM EDT Sun Sep 15 2019

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 1200 UTC surface analysis and satellite imagery through
1745 UTC.

...SPECIAL FEATURES...

Tropical Storm Humberto is centered near 28.9N 77.9W at 15/1500
UTC, or 165 nm ENE of Cape Canaveral Florida, moving NNW at 6 kt.
Estimated minimum central pressure is 997 mb. Maximum sustained
wind speed is 75 kt with gusts to 90 kt. Numerous moderate to
scattered strong convection extends outward from the center 100
nm NW quad, from 90 nm NE quad, 80 nm SE quad. On the forecast
track, the center of Humberto will continue to move away from the
Bahamas and remain well offshore of the east coast of Florida
through Wednesday. Please read the latest NHC forecast/advisory
under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC, or at the website
hurricanes.gov for more details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is along 20W from 18N southward,
moving W around 15 kt. The wave shows up well in 700 mb trough
diagnostics, the TPW imagery and latest ASCAT pass. Scattered
showers are present in the vicinity of the wave axis.

A tropical wave with axis along 37W from 16N southward is moving
W at 10-15 kt. The wave is well depicted in satellite imagery and
TPW imagery. Scattered moderate convection is seen from 06N-12N
between 36W-41W. Shower activity remains disorganized and only a
slow development is anticipated during the next day or two.
However, environmental conditions are forecast to become more
conducive for gradual development through the middle of the week,
and a tropical depression is likely to form by the end of the week
while the system moves slowly westward or west-northwestward.
There is a low chance of development in the next 48 hours.

A central Atlantic tropical wave with axis along 53W from 06N-21N
is moving W around 20 kt. This wave is well depicted in model
guidance and satellite imagery. Scattered moderate convection is
seen from 12N-17N between 51W-58W, and scattered showers south of
12N near the ITCZ. The wave will bring enhanced rain to the Lesser
Antilles and eastern Caribbean on Monday.

An eastern Caribbean tropical wave extends its axis along 62W from
20N, moving west around 15 kt. Scattered moderate convection covers
the area from 13N-18N between 61W-64W, including the islands of
Dominica, Guadeloupe, St. Kitts, and other nearby islands.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from Guinea-Bissau near 13N16W to
10N30W to 07N44W. The ITCZ continues from 07N44W to 09N51W, then
resumes west of the wave from 09N54W. Aside from the convection
already discussed in the Tropical Waves section above, scattered
moderate convection is noted within 180 nm of the monsoon trough
between 24W-36W, and between 41W-47W.

GULF OF MEXICO...

The weather over the Gulf of Mexico is dominated by a large mid to
upper-level low that is centered over the central portion of the
basin near 26N92W. There is a sharp trough at 850 and 925 mb over
the south-central Gulf. A surface trough is now being analyzed
from the western Yucatan Peninsula near 25N90W to 18N91W. Upper-
level diffluence and divergence on the east side of the upper-low
are enhancing scattered to numerous moderate convection from
25N-28N between 82W-93W. Scattered showers and tstorms are seen
in the southern Bay of Campeche from 19N-21N between 90W-92W. The
latest ASCAT pass and nearby observations depict fresh easterly
winds across the northern half of the basin north of 24N, while
gentle winds prevail south of 24N.

A large area of disorganized showers and thunderstorms over the
central and eastern Gulf of Mexico is associated with an upper-
level low and a weak surface trough. Some slight development of
this system is possible during the next couple of days while it
moves westward over the western Gulf of Mexico. The system is
forecast to move inland along the northwestern Gulf coast by late
Monday or Tuesday, and further development is not expected after
that time. Weak high pressure will build over the Gulf through mid
week.

CARIBBEAN SEA...

Refer to the Tropical Waves section above for details on the
tropical waves moving and approaching the basin.

Relatively dry air covers the central Caribbean. In the SW
Caribbean, no significant convection is seen in the western
Caribbean Sea except with isolated showers and tstorm near
Belize in the Gulf of Honduras. To the south, Scattered moderate
strong convection is seen from Colombia, Panama and Costa Rica
due to the proximity of the Pacific monsoon trough. Most of the
convection has develop below 11N southward between 75W-83W.
The latest ASCAT pass depicts fresh to strong trades in the
south-central Caribbean.

Moderate to fresh trade winds will dominate much of the basin. A
tropical wave moving across the eastern Caribbean today will reach
the central Caribbean on Mon. Another tropical wave will approach
Barbados late today, move across the eastern Caribbean Mon, and
into the central Caribbean through mid week, bringing widespread
showers and thunderstorms, gusty winds and building seas. Northerly
swell will reach the Atlantic passages into the Caribbean Sea
late on Mon due to a mid-latitude low centered near 40N43W.

ATLANTIC OCEAN...

Refer to the sections above for details on T.S. Humberto and the
tropical waves moving across the basin.

A storm-force mid-latitude low currently centered near 40N43W with
a front extending south entering the forecast area near 31N40W to
27N51W to 30N63W. A surface trough ahead of the front is from
30N38W to 25N48W. Scattered showers and tstorms extend southeast
60 to 80 nm from the trough and along the frontal boundary. To the
east, 1030 mb high pressure to the north remains in control across
the area.

Humberto will strengthen to a hurricane near 29.5N 77.7W this
evening, move to 30.0N 77.1W Mon morning, 30.3N 75.9W Mon evening,
30.7N 74.4W Tue morning, and 31.6N 69.6W Wed morning. Humberto
will change little in intensity as it moves to near 34.5N 62.8W
early Thu, and continue to near 39.0N 57.0W Fri. Northerly swell
will reach the Atlantic passages into the Caribbean Sea late on
Mon.

Northerly swell from a large, storm-force mid-latitude low
currently centered near 40N43W, will reach the Atlantic passages
into the Caribbean Sea late on Monday and continuing into mid-
week.

$$
Torres
This weather bulletin was brought to you by:
www.nashvilleweather.net