Atlantic Tropical Weather Discussion (Text)

AXNT20 KNHC 132332

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
623 PM EST Wed Dec 13 2017

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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through 
2315 UTC.


A tight pressure gradient between a 1033 mb high pressure located
just south of the Azores and a low pressure system over western 
Africa is resulting in strong to minimal gale force winds in the 
High Seas Forecast area called Agadir, along the coast of 
Morocco. Very rough seas are within the area of these winds. 
Winds and seas are forecast to gradually diminish tonight into 
Thu. Please, refer to the Meteo-France High Seas Forecast for 
more details. 

The monsoon trough extends from the African coast near 07N12W to 
06N18W. The Intertropical Convergence Zone axis continues from 
06N18W to the coast of NE Brazil near 03N51W. Scattered moderate 
convection is within about 60 nm N of the ITCZ axis between 23W- 


A reinforcing and dry cold front is dissipating along 22N. A 1019
mb high pressure has developed over the NE Gulf while a 1023 mb 
high pressure is near Tampico, Mexico. Under this weather 
pattern, mainly light to gentle winds are noted across the Gulf 
region with the exception of moderate northerly winds across the 
SE waters, including the Yucatan Channel. Broken cold air 
stratocumulus clouds are still noted over the eastern Gulf in 
the wake of the dissipating front. Water Vapor imagery shows a 
band of transverse high clouds over northern Mexico and the NW 
Gulf in association with a subtropical jet, that is drawing 
upper level moisture from the EPAC region into the Gulf of 
Mexico. Looking ahead, another cold front is forecast to enter 
the northern Gulf Thu, then reach from the Florida Big Bend area 
in the NE Gulf to near Tampico Mexico by Fri afternoon, then 
stall from Tampa to the Bay of Campeche on Sat before lifting 
back to the W and NW through Sun. Gale force winds are possible 
along the coast of Mexico near Tampico Fri night and Sat. 

A weakening stationary front extends from northern Haiti to the 
easternmost tip of Jamaica to the SW Caribbean near 11N80W. A 
wide band of multi-layered clouds with embedded showers is 
associated with the front. A well defined swirl of low clouds is 
along the frontal boundary near 13N79W moving southward. This 
front produced heavy rains over eastern Cuba Sunday through 
Thuesday. The front will continue to dissipate to a remnant 
trough tonight. Moisture associated with this trough is forecast 
to move westward across the western Caribbean Thu and Fri in an 
easterly wind flow. An earlier scatterometer satellite pass 
showed moderate to locally fresh northerly winds across the 
Windward Passage in the wake of the front. Gentle to moderate 
trades are noted E of the front over the east and central 
Caribbean, with moderate to fresh winds within about 90 nm of 
the coast of Colombia. Winds are forecast to increase to 20-25 
kt over the south-central Caribbean on Thu night, with gale 
conditions possible Sat night and Sun night as high pressure 
builds N of area. A reinforcing and dry cold front has reached 
western Cuba. This will reinforce the cool and dry airmass over 
western Cuba. Temperatures could drop below 10 degree Celsius 
(50F)in some places across the Havana-Matanzas plains overnight 

Cloudiness has increased over Hispaniola today due to the 
proximity of a weakening stationary front that currently crosses 
northern Haiti. Isolated to scattered light to moderate showers 
are still possible tonight and early Thu. Then, moisture will 
diminish later on Thu as the frontal boundary continues to weaken
and begins to drift westward as a trough. 

A reinforning cold front enters the forecast area near 31N63W and
continues SW across the central Bahamas into western Cuba. Fresh 
to strong W-NW winds follow the front but mainly N of 27N based 
on latest scatterometer data. A weakening stationary front is 
farther east and stretches from 31N60W to northern Haiti into 
the Windward Passage and the Caribbean Sea. Fresh to strong S-SW 
winds are aslo noted ahead of this front N of 27N to about 55W. 
The reinforcing cold front will continue to move SE while 
gradually dissipating on Thu. The stationary front will also 
dissipate on Thu. A ridge will then build along 25N in the wake 
of the secondary front. Another cold front is forecast to move 
off the NE Florida coast early Fri, reach from Bermuda to South 
Florida Sat, then reach from 24N65W to eastern Cuba early Sun. 
The remainder of the Atlantic Ocean is under the influence of a 
1033 mb high pressure located just south of the Azores. This 
high extends a ridge SW to near the NE Caribbean. 

For additional information please visit 


Standard version of this page

Alternate Formats
About Alternates - E-Mail Advisories - RSS Feeds

Cyclone Forecasts
Latest Advisory - Past Advisories - About Advisories

Marine Forecasts
Latest Products - About Marine Products

Tools & Data
Satellite Imagery - US Weather Radar - Aircraft Recon - Local Data Archive - Forecast Verification - Deadliest/Costliest/Most Intense

Learn About Hurricanes
Storm Names Wind Scale - Prepare - Climatology - NHC Glossary - NHC Acronyms - Frequently Asked Questions - AOML Hurricane-Research Division

About Us
About NHC - Mission/Vision - Other NCEP Centers - NHC Staff - Visitor Information - NHC Library

Contact Us

NOAA/ National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
Privacy Policy
About Us
Career Opportunities
Page last modified: Wednesday, 13-Dec-2017 23:32:25 UTC