[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 142318
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 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 1800 UTC surface analysis and satellite imagery through
2220 UTC.

...SPECIAL FEATURES...

The remnants of Fred are in the SE Gulf of Mexico, off the NW
coast of Cuba, near 24.0N 84.6W at 2100 UTC, or about 130 nm W-NW
of Havana, Cuba. It is moving WNW at 11 kt with an estimated
minimum central pressure at 1012 mb. Maximum sustained wind speed
is 30 kt with gusts to 40 kt occurring in squalls NE of the
center. Wave heights with the remnants of Fred are in the 8-10 ft
range. Latest satellite imagery shows scattered moderate to
strong convection affecting the waters of western Cuba into the SE
Gulf from 21N to 26N and between 79W to 86W. 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
evening, 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
tonight and to a tropical storm near 26.6N 87.1W on Sunday.
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 nearing the Lesser Antilles,
located near 15.9N 60.7W at 2100 UTC or about 48 nm E-SE of
Guadeloupe. It is moving W at 23 kt, with an estimated minimum
central pressure of 1010 mb. Maximum sustained wind speed is 35 kt
with gusts to 45 kt. Wave heights with this system are in the
9-12 ft range. Latest visible satellite imagery shows a small
tropical storm that is producing strong thunderstorms, but there
are little 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 22W, south of 20N,
moving W at about 15 kt. Morning scatterometer satellite data
showed a broad curvature between Africa and the Cabo Verde
Islands, which is difficult to distinguish from the nearby monsoon
trough. Scattered moderate isolated strong convection is noted
from 06N to 13.5N and between 17W and 22W.

Another Atlantic tropical wave has its axis along 38W, 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 70W, south of 24N,
and it is moving W at 10-15 kt. Recent scatterometer satellite
data depicted 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 26N and between 61N and 71W. Another area of
scattered moderate convection is found in the Caribbean Sea near
the wave axis from 13N to 16N between 68W and 72W.

Another Caribbean tropical wave has its axis across the Gulf of
Honduras along 87W, south of 19N, extending to the E Pacific,
and it is moving W at around 10 kt. The convection associated with
this wave is occurring over Central America and the waters on the
Pacific side.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends across the coast of Mauritania near
20N17W to 07N32W and to 06N40W. The ITCZ then continues from
06N40W to 05N53W. Scattered moderate convection is noted near the
monsoon trough between 22W and 31W. Another area of scattered
moderate convection is found within 250 nm north of ITCZ between
40W and 53W.

...GULF OF MEXICO...

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

An upper level low over the NE Gulf of Mexico is interacting with
the remnants of Fred, causing a large area of showers and isolated
thunderstorms from 21N to 28N and between SW Florida and 87W.
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 2-4 ft
prevail.

The remnants of Fred will move to 25.0N 85.7W Sun morning, 26.6N
87.1W Sun afternoon, 28.0N 87.9W Mon morning, 29.4N 88.2W Mon
afternoon, inland to 30.9N 88.3W Tue morning. Following Fred will
be Tropical Storm Grace near 15.9N 60.7W 1010 mb at 5 PM EDT
moving W at 23 kt. Maximum sustained winds 35 kt gusts 45 kt.
Grace will move to 18.3N 70.6W by Mon afternoon, 19.2N 72.8W Tue
morning, and inland to 20.2N 75.3W Tue afternoon. Grace will move
inland over 22.4N 80.1W by Wed afternoon.

...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 60 nm north of the
coast of Panama. Moderate to occasionally fresh trades and seas
of 4-6 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. Clusters of deep convection associated with Grace
extend southward from the core of Grace to coastal Venezuela.

Tropical Storm Grace will move across the NE Caribbean to 16.5N
63.3W Sun morning, 17.1N 66.1W Sun afternoon, 17.7N 68.5W Mon
morning, 18.3N 70.6W Mon afternoon, 19.2N 72.8W Tue morning, and
inland to 20.2N 75.3W Tue afternoon. Grace will move inland over
22.4N 80.1W by Wed afternoon. High pressure will build across the
region behind Grace to freshen trade winds across the E and
central basin Tue through 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
and moderate thunderstorm activity along the E coast of Florida
and the Straits of Florida. 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 25N 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, Fred will move across the E Gulf and
inland across the NE Gulf coast Tue. Tropical Storm Grace will
move to 16.5N 63.3W Sun morning, 17.1N 66.1W Sun afternoon, 17.7N
68.5W Mon morning, 18.3N 70.6W Mon afternoon, 19.2N 72.8W Tue
morning, and inland to 20.2N 75.3W Tue afternoon. Grace will move
inland over 22.4N 80.1W by Wed afternoon. Atlantic high pressure
will build modestly across the region behind Grace by Wed and
begin to freshen trade winds south of 24N.

$$
Stripling
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