000
AXNT20 KNHC 281721
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu Oct 28 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 
1630 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: Satellite derived wind data this
morning confirm minimal gale force winds over the NW Gulf behind 
a strong cold front moving across the eastern Gulf today. The
front currently extends from the central Florida Panhandle to 
near Veracruz, Mexico. Very active convection is along the front, 
and is also occurring within 60-120 nm ahead of it in a squall 
line, where frequent lightning and strong gusty winds prevail. 
Fresh to strong southerly winds will continue ahead of the front 
today as it moves into the Gulf coast of Florida. Winds and seas 
are expected to peak tonight. At this time, W to NW winds of 30-35
kt and seas in the 10-15 ft range are expected. These dangerous 
marine conditions will begin to gradually diminish from W to E 
late Fri into Sat. Please, see the latest NWS High Seas Forecast 
issued by the National Hurricane Center at website 
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further details.

...TROPICAL WAVES...

An Atlantic tropical wave has been repositioned along 27W from 
19N southward moving W at 10 to 15 kt. Long term satellite imagery
animations as well as precipitable water animation suggest that
some low level moisture has continued moving westward ahead of the
wave, to along 32W, where a 1011 mb surface low is along the
monsoon trough near 10.5N32W. However the main wave energy appears
to be consolidating further to the east along 27W. Very active
convection continues to the south and east of the wave, where
satellite imagery shows scattered moderate to convection from 04N
to 08N between 23W and 30W, and from 04N to 15N between 19W and
24W. Scattered moderate convection is noted within 90 nm across
the SW quadrant of the low along 10.5N32W.

...MONSOON TROUGH/ITCZ...

The monsoon trough exits the Guinea coast near 11N15.5W and 
meanders westward to 09.5N18.5W to 11.5N26W to 1011 mb low pres 
near 10.5N32W to 08N37W. A segment of the ITCZ extends from 05N43W
to the coast of French Guiana near 05N52W. Numerous moderate to 
strong convection is seen from 03N to 09N between 10W and 19W. 
Scattered moderate convection is noted from 02.5N to 06.5N between
30W and 40W.

...GULF OF MEXICO...

A strong cold front extends from the central Florida Panhandle to
the coast of Mexico near Veracruz, and is racing quickly SE across
the basin today. Strong tstorms and squalls are occurring along
and within 120 nm ahead of the front. Gale force W to NW winds 
and large seas to 14 ft are occurring behind the front and N of
26N, while strong NW to N winds are elsewhere behind it.
Scatterometer winds from this morning also depicted strong SW 
winds to 30 kt ahead of the front moving into the Florida Big 
Bend, where seas of 8-10 ft prevail. Please see the Special 
Features section for more details. The front is supported by a 
large area of low pressure shifting eastward across the eastern 
United States, producing a strong pressure gradient over the 
northern Gulf. This will support the strong to gale force winds 
across the northern Gulf waters behind the front through Fri. 

...CARIBBEAN SEA...

Generally fair and stable atmospheric conditions prevail across
all but the SE Caribbean today. Morning scatterometer data showed
moderate to fresh trade winds across the south central Gulf
between 65W and 74W, where peak seas were to 8 ft. Scatterometer
data also showed fresh southerly winds opening up across the NW
Caribbean and flowing through the Yucatan Channel and into the SE
Gulf of Mexico, ahead of the cold front. Wind and seas are
generally more tranquil across the remainder of the Caribbean
today. Active convection across the SW Caribbean has diminished
somewhat this morning. Scattered moderate isolated strong
convection is seen within 90 nm of the NW coast of Colombia, and S
of 15N to the W of 81W. 

A weak ridge over the northern Caribbean Sea will continue to support
mainly gentle to moderate trade winds across the basin, with 
locally fresh winds possible in the Gulf of Honduras and off the 
coast of Venezuela. A cold front will enter the basin through the
Yucatan Channel tonight. This front will move through the NW 
Caribbean into the weekend, before stalling from the Windward 
Passage to northern Nicaragua by Sun. Moderate to fresh NW winds 
and seas to 8 ft can be expected behind the cold front. 

...ATLANTIC OCEAN...

A cold front enters the discussion area near 31N60W to 27N66W 
where it becomes stationary to the northern Bahamas near 25N77W.
Active convection continues along and within 90 nm southeast of 
both of these boundaries. South Florida. Fresh to strong westerly
winds are occurring behind the front, to the N of 29N and E of 
70W, while fresh SW winds prevail southeast of the front and N of 
24N to 60W. Seas are 6-11 ft in NW swell behind the front and 6-10
ft ahead of it. The remainder of the Atlantic is under the 
influence of a 1023 mb high pressure located near 30WN27W. This 
system extends a ridge SW across the Greater Antilles. Light and 
variable winds are along the ridge axis while a belt of gentle to 
moderate trades is along the southern periphery of the ridge. 

The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. Ash cloud is
slowly drifting SW. High volcanic ash concentration remains in 
the vicinity of the volcano. Marine and aviation interests should 
monitor this ongoing situation by reading the Volcanic Ash 
Advisory issued by Meteo- France, at 
http://vaac.meteo.fr/volcanoes/la-palma/.

A aforementioned cold front will move east and weaken N of 27N,
while the remaining stationary portion will drift northward and 
gradually dissipate through Fri. The next cold front will move 
off the SE U.S. coast tonight, then gradually reach from Bermuda 
to the Windward Passage over the weekend. Strong winds with seas 
in excess of 8 ft are expected to develop on both sides of the 
front this afternoon through Sat night, mainly N of 26N. Moderate
to large NE swell will dominate the waters W of 65W through the 
weekend. 

$$
Stripling