AXNT20 KNHC 191741
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sat Jun 19 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
Claudette: Tropical Storm Claudette is centered near 31.8N 88.6W
at 19/1800 UTC or 70 nm NNW of Mobile Alabama moving NNE at 12
kt. Estimated minimum central pressure is 1007 mb. Maximum
sustained wind speed is 35 kt with gusts to 45 kt. Scattered to
numerous moderate and isolated strong convection extends outward
up to 330 nm in the east semicircle. A tail of scattered moderate
to strong convection extends along a line that is 60 nm wide from
30N86W to 28N87W to 27N91W to 24N94W. Recent buoy observations
offshore of Mississippi through the western Florida Panhandle
indicate that S winds around 30 kt and seas as high as 13 ft are
still occurring north of 28.5N. Winds of 25 kt and seas of 10 ft
or higher will continue offshore Alabama and the western Florida
Panhandle through tonight, before diminishing Sunday. Claudette is
expected to turn toward the NE later today, followed by a turn to
the ENE tonight or Sunday. On the forecast track, the system
should move farther inland across portions of the southeast U.S.
through Sunday night, and over the western Atlantic on Monday.
Claudette is expected to weaken to a tropical depression later
today, but then become a tropical storm again when it moves across
the Carolinas Sunday night or early Monday. Claudette is expected
to produce very heavy rain and flash flooding across portions of
the Gulf Coast and southeastern U.S. See the latest NHC Public
Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml and
Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT3.shtml
for more details.
East Atlantic Gale Warning: Northerly gales are occurring in a
small area off the coast of Agadir Morocco from 30N-31N between
09.5W and 11W. According to the forecast from Meteo France, the
gales will continue through 20/0000 UTC tonight. Please see the
latest High Seas Warning and High Seas Forecast products from
Meteo France at weather.gmdss.org/II.html for details.
The axis of an Atlantic tropical wave is along 38W from 15N
southward, moving W at 15-20 kt. Scattered moderate convection is
noted from 05N-11N between 29W-41W.
The axis of a well-defined Atlantic tropical wave extends from
21N59W to 05N61W and is moving W at 15-20 kt. Isolated moderate
convection is noted within 330 nm either side of the wave axis
from 10N-16N, including near Dominica and near Trinidad.
The axis of a central Caribbean tropical wave is along 79W from
19N southward, moving W at 15-20 kt. Isolated moderate convection
is mainly confined to the SW Caribbean, south of 11.5N, and also
near the NE coast of Honduras.
The axis of a western Caribbean tropical wave is near 86/87W from
19N southward, moving W at less than 5 kt. Isolated showers are
present in the vicinity of the wave axis in the Gulf of Honduras.
The monsoon trough passes through the coast of Guinea-Bissau near
11N15W to 09N19W to 08N25W. The ITCZ continues from 08N25W to
08N36W, then resumes west of a tropical wave from 06N40W to
03N48W. Aside from the convection described in the tropical waves
section, an area of numerous moderate to scattered strong
convection is noted south of the monsoon trough, off the coasts of
Sierra Leone and Liberia from 04N-09N, east of 16W. Scattered
moderate convection is noted along the monsoon trough from 05N-09N
between 20W-25W. Scattered showers are near the ITCZ between
GULF OF MEXICO...
Refer to the Special Features section above for details on
Tropical Storm Claudette and the convection occurring over the
central Gulf of Mexico. A recent ASCAT pass shows that light to
gentle winds cover the western Gulf, west of 94.5W. Moderate SE to
S winds cover the southeastern and south-central Gulf of Mexico.
Wind speeds are fresh north of 26N, closer to Claudette. Seas are
4-5 ft in the west-central Gulf and 2-3 ft in the SW Gulf.
For the forecast, conditions in the NE Gulf related to Claudette
will persist through tonight and subside Sunday. High pressure is
forecast to build in across the basin in the wake of Claudette
tonight into early next week. Fresh to locally strong southerly
return flow will set up across the western Gulf on Sun.
Isolated showers and tstorms are occurring near the tropical
waves, described above in the tropical waves section. No other
significant weather features or areas of precipitation are noted.
A recent ASCAT pass shows strong trades over the south-central
Caribbean Sea, with fresh trades elsewhere over the central
Caribbean between 67W-81W, south of 18N. Moderate to fresh winds
cover the E Caribbean and the Gulf of Honduras. Moderate ESE winds
are over the far NW Caribbean. Seas are in the 8-10 ft range over
the central Caribbean and 4-6 ft over most of the remainder of the
For the forecast, fresh to strong trades will continue over the
south-central Caribbean through Tuesday morning. Pulsing fresh to
strong E to SE winds are expected in the Gulf of Honduras at
night through Wed night. A tropical wave currently along 79W will
continue to move W across the basin today and enhance shower and
thunderstorm activity. A well defined tropical wave is reaching
the Lesser Antilles now and will increase the likelihood of
showers and isolated thunderstorms.
A cold front extends from 31N60W to 30N66W. A weakening stationary
front continues from 30N66W to 31N70W. An upper-level trough axis
extends from 31N60W to 23N68W to 26N73W. Isolated light showers
are around the periphery of the upper-trough, and extend east of
Florida, over the Bahamas, north of Hispaniola and north of 23N
between 56W-64W. At the surface, high pressure ridging and light
to gentle winds generally prevail north of 26N and west of 62W,
with seas of 3-4 ft. Farther south, moderate wind speeds and seas
of 5-6 ft are north of Puerto Rico.
Farther east, a 1028 mb surface high pressure is near 32N45W. A
1021 mb low near 28N27W extends a cold front from the low to
26N30W to 30N34W. Fresh winds and 7-8 ft seas are on the north
side of this low pressure. An upper-level trough axis extends
from 31N45W to 21N52W. Scattered showers are seen east of the
upper-trough axis, within 60 nm either side of a line from 31N42W
to 28N43W to 24N47W. A recent ASCAT pass shows light to moderate
winds across the basin west of 32W, from 24N-31N, where seas are
4-6 ft. Moderate to fresh trade winds prevail over the tropical
Atlantic, with seas of 6-7 ft. See the Special Features section
above for details on the Gale Warning near the coast of Morocco.
For the forecast west of 65W, a ridge will dominate the area
during the next several days. Fresh to strong winds are expected
to pulse at night over the Hispaniola adjacent waters, including
the approaches to the Windward Passage through Wed night.