Skip Navigation Links
NOAA NOAA United States Department of Commerce

Atlantic Tropical Weather Discussion



000
AXNT20 KNHC 122327
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
627 PM EST Tue Dec 12 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.

...ITCZ/MONSOON TROUGH... 

The monsoon trough enters the Atlantic Ocean through Liberia,
Africa and continues to near 06N13W. The Intertropical Convergence
Zone extends from 06N13W to 07N20W to 04N35W to the coast of NE 
Brazil near 02N51W. Scattered moderate isolated strong convection 
is within about 180 nm north of ITCZ axis W of 30W.

...DISCUSSION...

GULF OF MEXICO...
A reinforcing and dry cold front extends from northern Florida 
across the northern Gulf waters to south Texas. The front will 
move across the southeast Gulf by early Wed morning followed by 
moderate to fresh NW winds over the eastern Gulf, and gentle 
moderate northerly winds elsewhere. A 1033 mb high pressure 
located over Texas extends a ridge over the remainder of the Gulf
region, and will continue to build eastward in the wake of the
front. This will reinforce the cool and dry airmass over the 
State of Florida. Cold air stratocumulus clouds are noted ahead of
the front moving quickly southward. Patches of low level clouds 
with embedded light showers are over the Bay of Campeche, where a 
surface trough is analyzed on the 1800 UTC surface map. The next 
cold front will move into the northern Gulf waters Thu, and reach
from the Florida Big Bend area in the NE Gulf to near Tampico 
Mexico by early Fri.

CARIBBEAN SEA...
A quasistationary frontal boundary persists across the basin and
extends from eastern Cuba to the SW Caribbean near 10N82W. The 
most recent scatterometer pass showed fresh to strong northerly 
winds within about 240 nm to the W of the front and mainly south
of 20N. A band of broken to overcast multi-layered clouds prevails
to the W of the front affecting from eastern Cuba to western 
Panama and Costa Rica. Some convective activity is also noted 
along the frontal boundary just south of Jamaica. A swirl of low
clouds is seen on visible satellite imagery near 15N71W related to 
a weak easterly perturbation. Light to gentle winds dominate the 
eastern Caribbean with seas generally below 5 ft based on altimeter
data and buoy observations. The front is forecast to meander 
across the central Caribbean and gradually weaken through Thursday.

HISPANIOLA... 
Moisture is forecast to increase across the island on Wed as the
frontal boundary currently located over eastern Cuba drifts eastward
across the Windward Passage into Hispaniola. This will increase 
the likelihood of showers Wed and possibly Thu. 

ATLANTIC OCEAN...
A quasistationary frontal boundary enters the forecast area near 
31N59W, then continues SW to the SE Bahamas and eastern Cuba into 
the Caribbean Sea. A band of multi-layered clouds with embedded 
showers is associated with the front forecast to dissipate by late
Wed. A reinforcing cold front is just moving off NE Florida and 
it is forecast to reach from near Bermuda to NW Cuba early on Wed.
Fresh to strong SW flow is noted ahead of this front mainly N of 
30N. A weak and narrow surface ridge extends from the Gulf of 
Mexico NE across S Florida to near Bermuda ahead of this 
reinforcing front. A third cold front enters the Atlantic Ocean 
through Mauritania, west Africa and continues W, then NW to near 
23N34W. The remainder of the Atlantic Ocean is under the influence
of a 1033 mb high pressure located just south of the Azores. 
Fresh to locally strong anticylonic flow is seen S and SW of the 
ridge, and generally E of 53W, where a surface trough is found 
drifting W. The pressure gradient between this high and a low 
pressure system over west Africa is resulting in gale force winds 
from 28N-31N between the coast of Africa and 13W. Fresh to strong 
winds are spreading west and south between the coast of Africa and
the Canary Islands.

For additional information 
please visit http://www.hurricanes.gov/marine

$$
GR