[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141056
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 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 0600 UTC surface analysis and satellite imagery through
1045 UTC.

...SPECIAL FEATURES...

Tropical Depression Fred is just inland the coast of north-central
Cuba near 23.3N 81.7W at 0900 UTC, or about 78 nm S of Key West,
Florida. It is moving WNW at 9 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 Fred are in the 8-10 ft
range. Latest satellite imagery shows scattered moderate to
isolated strong convection just south of Cuba from 20N to 22N and
between 78W-82W. Scattered moderate convection is over the
Straits of Florida between the Florida Keys and central Cuba. Fred
is expected to continue moving WNW near the N coast of central
Cuba through this morning, then turn to the NW tonight, followed
by a a northward motion by Sunday night. On the forecast track,
Fred is expected to pass west of the lower Florida Keys this
afternoon, move across the eastern Gulf of Mexico tonight through
Mon, and move inland over the northern Gulf coast Mon night.
Rainfall amounts of 3 to 5 inches with locally amounts up to 8
inches are possible over the Keys and southern Florida. Across the
Florida Big Bend and Panhandle, 3 to 7 inches with isolated
maximum totals of 10 inches are expected. 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.

Recently upgraded Tropical Storm Grace is located near 15.8N
55.6W at 0900 UTC or about 365 nm east of the Leeward Islands. It
is moving W at 19 kt, with an estimated minimum central pressure
of 1007 mb. Maximum sustained wind speed is 35 kt with gusts to
45 kt. Wave heights with this system are in the 8-10 ft range.
Satellite imagery shows that Grace is a small tropical storm.
Just over the past few hours large bursts of numerous moderate to
strong convection have become evident within 210 nm of the center
in the W quadrant. Grace is forecast to decrease its forward
motion during the next few days. On the forecast track, the center
of the storm is forecast to move over the Leeward Islands
tonight, over the Virgin Islands and Puerto Rico on Sun, and then
over the Dominican Republic on Mon. Some strengthening is forecast
during the next couple of days. Weakening is expected early next
week as the system interacts with the Greater Antilles. 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...

A new tropical wave is analyzed just off the coast of Africa along
18N from 04N to 20N. It is moving westward at about 15 kt.
Scattered moderate convection is east of the wave to the coast
of Africa from 06N to 14N.

A far eastern Atlantic tropical wave has its axis along 31W from
04N to 21N, moving westward near 20 kt. No significant convection
is associated to this wave.

The central Atlantic tropical wave that earlier was along 53W is
no longer identifiable.

An eastern Caribbean Sea tropical wave has its axis along 66W
south of 24N to inland South America. It is moving westward
at about 10 kt. Enhanced by an upper-level low to the north
near 29N61W, scattered to numerous moderate convection is noted
from 20N to 25N between 58W-66W. Scattered moderate to isolated
strong convection is north of Venezuela, and across central
Venezuela. This wave has a good track history.

A western Caribbean Sea tropical wave is along 84W from 19N
southward along the east coast of Honduras and Nicaragua to Costa
Rica, and is moving westward at 10-15 kt. No deep convection is
associated with this wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends across the coast of Mauritania near
18N16W to 08N25W and to 06N35W. The ITCZ then continues from
06N35W to near 07N43W to 05N51W. Scattered moderate to isolated
strong convection is within 180 nm south of the monsoon trough
between 20W-28W. Scattered moderate convection is within 60 nm
north of the ITCZ between 41W-46W.

...GULF OF MEXICO...

An elongated upper-level low across the eastern Gulf near 26N84W
is triggering scattered showers and isolated thunderstorms over
the SE Gulf and W coast of Florida. Otherwise a modest ridge of
high pressure across the northern Gulf coast states is supporting
gentle winds and low seas of 1 to 3 ft over most of the Gulf. The
exception will be the southeastern Gulf and Straits of Florida,
increasing pressure gradient between the ridge and Tropical
Depression Fred is creating moderate to locally fresh winds and
seas in the range of 4 to 6 ft.

For the forecast, expect deteriorating marine conditions across
most of the water east of 90W through the weekend and into
early Mon due to Fred. Tropical Depression Fred was near 23.3N
81.7W 1013 mb at 5 AM EDT moving WNW at 11 kt. Maximum sustained
winds 30 kt gusts 40 kt. Fred will move to near 24.0N 83.1W this
afternoon, then strengthen to a tropical storm near 25.4N 84.6W
late tonight with maximum sustained winds 35 kt gusts 45 kt and
slowly strengthen as it moves to near 27.0N 85.8W Sun afternoon,
to near 28.4N 86.7W late Sun night with maximum sustained winds 45
kt gusts 55 kt, to near 29.8N 87.3W Mon afternoon with maximum
sustained winds 50 kt gusts to 60 kt and inland to near 30.9N
87.4W late Mon night. Fred will weaken to a tropical depression
while moving inland late Tue night. High pressure will then build
over the area for the rest of the week.

...CARIBBEAN SEA...

Refer to the Special Features section for information on Tropical
Depression Fred, recently upgraded Tropical Storm Grace and the
Tropical Waves section for convection in the Caribbean Basin.

Gentle to moderate trade winds and seas at 4 to 6 ft are evident
over the central and eastern basin. Light to gentle trades and
seas of 1 to 3 ft are elsewhere over the basin.

For the forecast, recently upgraded Tropical Storm Grace near
15.8N 55.6W 1007 mb at 5 AM EDT is moving W at 19 kt. Maximum
sustained winds 35 kt gusts 45 kt. Grace will move to near 16.2N
58.5W this afternoon, to near 16.9N 61.8W late tonight, to near
17.7N 64.8W Sun afternoon with maximum sustained winds 45 kt gusts
55 kt, to near 18.3N 67.3W late Sun night, over the eastern
Dominican Republic near 18.9N 69.4W Mon afternoon and remain over
land near 19.8N 71.5W late Mon night with maximum sustained winds
40 kt gusts 50 kt. Grace will change little in intensity as it
moves to near 21.9N 75.6W late Tue night and to near 24.5N 79.7W
late Wed night.

...ATLANTIC OCEAN...

Aided by divergent winds associated with an upper-level low over
the eastern Gulf, a surface trough that is east of Florida along
a position from 30N79W to West Palm Beach. Florida is producing
scattered showers and isolated thunderstorms near the E Florida
coast and NW Bahamas. For additional convection across the
Atlantic Basin, refer to the Tropical Waves and Monsoon
Trough/ITCZ sections above. For more information on Tropical
Depression Fred and Tropical Storm Grace please read the Special
Features section.

The Atlantic ridge extends west-southwestward from the 1026 mb
Azores high across Bermuda to northern Florida. Light to gentle
winds and seas at 2 to 4 ft related to this ridge are found N of
25N between 27W and 72W. Moderate to locally fresh trades and seas
of 4 to 6 ft are found from 10N to 25N between the African coast
and Lesser Antilles, and between 72W and the Florida-Georgia
coast. South of 10N, gentle to moderate winds and seas at 4 to 6
ft are present.

For the forecast west of 65W, Tropical Depression Fred just
inland north-central Cuba is forecast to move into the eastern
Gulf of Mexico tonight as a possible tropical storm. Numerous
showers and scattered thunderstorms over the far southwest part
will gradually shift westward through tonight. Recently upgraded
Tropical Storm Grace near 15.8N 55.6W 1007 mb at 5 AM EDT is
moving W at 19 kt. Maximum sustained winds 35 kt gusts 45 kt.
Grace will move to near 16.2N 58.5W this afternoon, to near 16.9N
61.8W late tonight, to near 17.7N 64.8W Sun afternoon with maximum
sustained winds 45 kt gusts 55 kt, to near 18.3N 67.3W late Sun
night, over the eastern Dominican Republic near 18.9N 69.4W Mon
afternoon and remain over land near 19.8N 71.5W late Mon night
with maximum sustained winds 40 kt gusts 50 kt. Grace will change
little in intensity as it moves to near 21.9N 75.6W late Tue night
and to near 24.5N 79.7W late Wed night.

$$
Aguirre
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