[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141805
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sat Aug 14 2021

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1755 UTC.

...SPECIAL FEATURES...

The remnants of Fred are in the SE Gulf of Mexico, off the NW
coast of Cuba, near 23.3N 83.2W at 1500 UTC, or about 110 nm SW
of Key West, Florida. It is moving WNW at 10 kt with an estimated
minimum central pressure at 1013 mb. Maximum sustained wind speed
is 30 kt with gusts to 40 kt. Wave heights with the remnants of Fred
are in the 8-10 ft range. Latest satellite imagery shows
scattered moderate to isolated strong convection affecting from
19N to 27N and between 77W to 88W. Fred is expected to turn toward
the northwest by tonight, followed by a northward motion by
Sunday night. On the forecast track, Fred or its remnants are
expected to pass west of the lower Florida Keys this afternoon,
move across the eastern Gulf of Mexico tonight through Monday, and
move inland over the northern Gulf coast Monday night.Fred is
expected to re- develop into a tropical depression on Sunday, with
gradual strengthening to a tropical storm expected after the
system re- develops. Please read the latest HIGH SEAS FORECAST
issued by the National Hurricane Center at website-
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NHC
Forecast/Advisory and Public Advisory at www.hurricanes.gov for
more details.

Tropical Storm Grace is quickly approaching the Lesser Antilles,
located near 16.2N 58.7W at 1800 UTC or about 160 nm east of the
Leeward Islands. It is moving W at 20 kt, with an estimated
minimum central pressure of 1007 mb. Maximum sustained wind speed
is 40 kt with gusts to 50 kt. Wave heights with this system are
in the 9-12 ft range. Visible satellite imagery shows a small
tropical storm that is producing strong thunderstorms, but there
are no signs of banding. Most of the convection is located west
of the center, and is already affecting some of the Leeward
Islands. Grace is forecast to move toward the west- northwest with
a gradual decrease in forward speed during the next several days.
On the forecast track, the center of Grace is expected to move
over the Leeward Islands tonight, over the Virgin Islands and
Puerto Rico on Sunday, over the Dominican Republic on Monday, and
then between the southeastern Bahamas and Cuba on Tuesday. Some
strengthening is forecast during the next day or so. Grace is
likely to weaken while it moves near and across the Greater
Antilles Sunday night through Monday night. Please read the latest
HIGH SEAS FORECAST issued by the National Hurricane Center at
website- https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the
latest NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

An Atlantic tropical wave has its axis along 20W, south of 20N,
and it is moving W at about 15 kt. Scatterometer satellite data
show a broad curvature between Africa and the Cabo Verde Islands,
which is difficult to distinguish from the nearby monsoon trough.
Scattered moderate convection is noted from 06N to 12N and
between the coast of Africa to 23W.

Another Atlantic tropical wave has its axis along 33W, south of
20N, and it is moving W at around 20 kt. The wave is surrounded by
a dry environment, inhibiting the development of showers and
thunderstorms.

A Caribbean tropical wave has its axis along 68W, south of 24N,
and it is moving W at around 10 kt. Recent scatterometer satellite
data depict a broad surface trough, especially on the northern
portion of the wave. The plume of moisture associated with the
wave is interacting with an upper level low south of Bermuda,
resulting in a large area of showers and isolated thunderstorms
from 21N to 27N and between 57N and 70W. Another area of scattered
moderate convection is found in the Caribbean Sea near the wave
axis from 13N to 16N.

Another Caribbean tropical wave has its axis along 85W, south of
19N, extending from the NW Caribbean to the E Pacific, and it is
moving W at around 10 kt. The convection associated with this wave
is occurring on the Pacific side.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends across the coast of Mauritania near
18N16W to 07N27W and to 06N36W. The ITCZ then continues from
06N37W to 05N44W and to 06N52W. Scattered moderate convection is
noted near the monsoon trough between 23W and 31W. Another area of
scattered moderate convection is found within 250 nm north of ITCZ
between 42W and 50W.

...GULF OF MEXICO...

Refer to the Special Features section for information on the
remnants of Fred.

An upper level low over the E Gulf of Mexico is interacting with
the remnants of Fred, causing a large area of showers and isolated
thunderstorms from 21N to 26N and between SW Florida and 88W.
Isolated showers are also noted in the central-north Gulf from 23N
to the coast of Louisiana and between 89W and 93W. The rest of the
basin enjoys fairly tranquil weather conditions. Outside of the
influence of Fred, gentle to moderate NE winds and seas are 2-4
ft prevail.

For the forecast, the remnants of Fred near 23.3N 83.2W 1013 mb
at 11 AM EDT moving WNW at 10 kt. Maximum sustained winds 30 kt
gusts 40 kt. Fred will move to 24.1N 84.2W this evening, 25.7N
85.5W Sun morning, 27.4N 86.7W Sun evening, 28.7N 87.4W Mon
morning, 30.0N 87.7W Mon evening, and inland to 31.5N 87.5W Tue
morning. Fred will move inland over 35.0N 86.5W by early Wed.

...CARIBBEAN SEA...

Refer to the Special Features section for information on Tropical
Storm Grace and the Tropical Waves section for convection in the
Caribbean Basin.

The E Pacific monsoon trough extends into the SW Caribbean and it
is producing an area of moderate scattered convection between the
coast of Costa Rica and NW Colombia and within 150 nm north of the
coast of Panama. Moderate to occasionally fresh trades and seas
of 5-7 ft are noted in the central Caribbean, while gentle to
moderate trades and seas of 3-5 ft are found in the E Caribbean. Light
to gentle trades and seas of 1 to 3 ft are elsewhere over the
basin.

For the forecast, Tropical Storm Grace near 16.2N 57.9W 1005 mb at
11 AM EDT moving W at 20 kt. Maximum sustained winds 40 kt gusts
50 kt. Grace will move to 16.8N 60.6W this evening, 17.5N 63.8W
Sun morning, inland to 18.1N 66.4W Sun evening, inland to 18.6N
68.6W Mon morning, inland to 19.4N 70.7W Mon evening, and 20.5N
72.8W Tue morning. Grace will change little in intensity as it
moves to 22.8N 77.3W by early Wed.

...ATLANTIC OCEAN...

Refer to the Special Features section for information on Tropical
Storm Grace and the Tropical Waves and Monsoon Trough/ITCZ for
details on area of convection.

An upper level low over the E Gulf is triggering some shower
activity along the E coast of Florida and the NW Bahamas. A couple
of troughs extend into our area from low pressure system near and
SW of the Azores. These troughs are not producing any deep
convection. The rest of the basin enjoys fairly tranquil weather
conditions. Moderate to locally fresh easterlies and seas of 5-7
ft prevail S of 27N and W of 60W. Also from 10N to 25N and between
30W and the Lesser Antilles, and S of 27N and the coast of Africa
to 30W. South of 10N, gentle to moderate winds and seas at 3-5 ft
are present. Light to gentle winds and seas of 3-5 ft are found
elsewhere in the basin.

For the forecast west of 65W, the remnants of Fred near 23.3N
83.2W 1013 mb at 11 AM EDT moving WNW at 10 kt. Maximum sustained
winds 30 kt gusts 40 kt. Fred will move to 24.1N 84.2W this
evening, 25.7N 85.5W Sun morning, 27.4N 86.7W Sun evening, 28.7N
87.4W Mon morning, 30.0N 87.7W Mon evening, and inland to 31.5N
87.5W Tue morning. Fred will move inland over 35.0N 86.5W by early
Wed. Tropical Storm Grace near 16.2N 57.9W 1005 mb at 11 AM EDT
moving W at 20 kt. Maximum sustained winds 40 kt gusts 50 kt.
Grace will move to 16.8N 60.6W this evening, 17.5N 63.8W Sun
morning, inland to 18.1N 66.4W Sun evening, inland to 18.6N 68.6W
Mon morning, inland to 19.4N 70.7W Mon evening, and 20.5N 72.8W
Tue morning. Grace will change little in intensity as it moves to
22.8N 77.3W by early Wed.

$$
DELGADO
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