Atlantic Tropical Weather Discussion

918
AXNT20 KNHC 170509
TWDAT 
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0615 UTC Sat Oct 17 2026
Tropical Weather Discussion for North America, Central America
Gulf of America, 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 0000 UTC surface analysis and satellite imagery through 
0430 UTC.
...SPECIAL FEATURES...
Gulf of America Gale Warning: A cold front is moving across the
northwestern Gulf tonight, and extends from Mobile Bay 
southwestward across coastal portions of SE Louisiana to 27N94.5W 
then south-southwestward and inland across eastern Mexico near 
Tuxpan. Scattered moderate showers are along most of the front N 
of 23N. Scattered showers and thunderstorms are occurring wihtin 
90 nm of the coast from the front near Tuxpan to the central Bay 
of Campeche. Strong northerly winds of 20 to 30 kt with frequent 
gusts above gale-force dominate most of the waters behind the 
front and W of SE Louisiana. Seas following the front have built 
to 6 to 10 ft, highest offshore of S Texas. Gale warnings are in 
effect for the Texas coastal waters through Sat morning. The front
is forecast to continue moving southeastward and reach from near 
Cedar Key, Florida to the central Bay of Campeche by Sat morning, 
and from the Straits of Florida to the NW coast of the Yucatan to 
the central Bay of Campeche by Sun morning. The front is then forecast
to move just SE of the basin on Mon, where it will gradually 
dissipate through Tue night. Strong to gale-force winds and rough 
to very rough seas are expected in the wake of the front over the 
waters from the north- central Gulf to the SW Gulf near Veracruz 
tonight, and from the NE Gulf to the central Bay of Campeche by 
Sat morning. Recent satellite scatterometer data showed that
northerly winds across the Mexican waters S of 25N to Veracruz 
had increased to 30-40 kt. Seas are expected to build very 
quickly tonight behind the front, reaching 10-14 ft offshore of S 
Texas in the next few hours, and to 15-20 ft offshore of Mexico by
sunrise. Gale-force winds may continue across the Veracruz area 
waters through early Mon. Strong high pressure will build over 
the lower Mississippi Valley in the wake of the front, promoting 
fresh to strong NE to E winds mainly over the eastern half of the 
Gulf, and fresh to strong winds NW to N winds across the SW Gulf 
waters Sat night through Tue. 
Please read the latest High Seas Forecast issued by the National 
Hurricane Center under AWIPS/WMO headers FZNT02 KNHC/HSFAT2 or at 
website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further 
details.
...MONSOON TROUGH/ITCZ...
The monsoon trough enters the Atlantic through the coast of
Senegal near 14N17W and extends SW to 09N22W. The ITCZ extends 
from 07N25W to 11N37W then resumes from 09N40W to the coast of
Guyana near 06.5N60W. Widely scattered moderate convection is 
noted from 03N to 09N E of 21.5W to the African coast, and from
06.5N to 10N between 40W and 50W. Scattered moderate to strong 
convection is occurring from 04.5N to 12N between 27W and 37W.
...GULF OF AMERICA...
See details above about the Gulf of America Gale Warning.
Abundant low level moisture has converged over the SE half of
the Gulf, ahead of the cold front, where a surface trough lingers
along 84W-85W. This moisture is interacting with an upper- level 
trough over central Gulf along 90W to produce scattered to locally
numerous showers and thunderstorms across much of the Gulf E of 
90W. Moderate or weaker winds and seas 2 to 4 ft are found east of
90W, while strong to gale-force N winds and building seas follow 
the cold front.
For the forecast, the is forecast to reach from near Cedar Key, 
Florida to the central Bay of Campeche by early Sat morning, and 
from the Straits of Florida and the SE Gulf to the eastern Bay of 
Campeche by early Sun morning. The front will then move just SE 
of the area on Mon where it will gradually dissipate through Tue
night. Strong to gale-force winds and rough to very rough seas 
are expected in the wake of the front over the west-central Gulf 
tonight, and over the southwest Gulf by Sat morning.  Looking ahead, 
strong high pressure will build over the lower Mississippi Valley
in the wake of the front, promoting fresh to strong NE to E winds
mainly over the eastern half of the Gulf, and fresh to strong 
winds NW to N winds across the SW Gulf waters Sat night through 
Tue. 
...CARIBBEAN SEA...
Abundant low level moisture is converging across the NW Caribbean
and interacting with the upper trough across the central Gulf of
America to produce scattered to numerous moderate to strong
convection across the NW basin S of 20N to the Gulf of Honduras
and W of 81W. A large cluster of strong thunderstorms has
developed across SW portions between the SE coast of Nicaragua 
and 80W. At the surface, the seasonal pressure gradient across the
region is leading to moderate to fresh trades across the central 
basin between 64W and 80W, with strong easterly winds offshore 
Colombia and in the Gulf of Venezuela. Moderate seas prevail 
across much of the Caribbean, with rough seas 7 to 8 ft offshore 
Colombia.
For the forecast, as a cold front moves across the Western 
Atlantic and the Gulf of America, the pressure gradient will relax
across the Caribbean basin. Under this weather pattern, expect 
moderate to fresh winds offshore Colombia and in the Gulf of 
Venezuela with moderate to locally rough seas near the coast of 
Colombia tonight and Sat. Moderate or weaker winds and slight to 
moderate seas are forecast elsewhere. An area of showers and 
thunderstorms will continue to affect the NW Caribbean tonight. 
Moisture associated with this feature will merge with the cold 
front moving across the Gulf this weekend. The front will likely 
reach western Cuba and the entrance to the Yucatan Channel by 
Tue.
...ATLANTIC OCEAN...
A cold front extends from 31N43W to 26N50W, and then becomes 
stationary to 25.5N74W. A reinforcing cold front follows to the N
of this first front, extending from 31N48W to 30N64.5W to just W
of Bermuda. 1024 mb high pressure is centered N of the fronts
across the western Atlantic along 56W, and is forcing moderate to
locally fresh NE to E winds north of the fronts and E of 70W. 
Seas are 6 to 8 ft in NE swell to the north of the fronts and east
of 60W, and 3-5 ft elsewhere N of fronts. Gentle to moderate SE 
to S winds prevail W of 70W and into the coast of Florida, where 
scattered showers and thunderstorms are occurring across the SE to
central Florida coastal waters W of 78W. Seas are 2 to 4 ft 
across these waters. To the southeast, a surface trough is 
analyzed from 29N37W to 18N40W with a 1013 mb low along the trough
near 23.5N37W. An upper level trough along 50W is providing 
favorable conditions for Scattered moderate isolated strong 
convection across this area N of 18N between 30W and 50W. The 
pressure gradient between the Atlantic ridge and the low center is
driving fresh to strong SE to S winds E of the trough and low to 
about 31W and between 20N and 27N, where seas are 7 to 8 ft. To 
the S of these features, a low level easterly wave has a surface 
trough along 37W-38W, S of 16N. Scattered moderate to strong 
convection is occurring from 04.5N to 12N between 27W and 37W with
and E this wave. Elsewhere across the Atlantic, moderate or 
weaker winds and seas are evident E of 35W.
For the forecast west of 55W, a pair of weak frontal boundaries
across the offshore Atlantic east of 70W will merge, then 
dissipate through early Sat, ahead of a strong cold front that 
will move off the coast of northeast Florida by early Sat morning.
The front will reach from 31N72W to the Straits of Florida by 
early Sun morning, from near 31N70W to western Cuba by early Mon 
morning, then stall and dissipate into mid week. Strong to near- 
gale force winds and rough to very rough seas will follow the 
front affecting mainly the waters W of 65W through Tue.