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Atlantic Tropical Weather Discussion

AXNT20 KNHC 231715

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
115 PM EDT Fri Mar 23 2018

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 1200 UTC surface analysis and satellite imagery through 
1700 UTC. 



A combination of strong surface high pressure moving east off the
U.S. coast and lower pressure over northern South America is
expected to support winds to gale force near the coast of
Colombia beginning this evening. These winds are expected to be 
strongest during the evening and overnight hours over the next 
several days while the surface weather pattern persists. For more
details please see High Seas Forecasts issued by the National 
Weather Service under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC. 
This information can also be found at the following website:  


The monsoon trough extends from Sierra Leone on the African coast
near 08N13W to 05N19W. The ITCZ continues from 05N19W to 00N34W 
to the northeast coast of Brazil near 02S44W. Scattered moderate 
convection is present from 03N to 05N between 19W and 23W. Similar
convection is occurring from 03N to 06N between 10W and 14W. 



Fair weather prevails across the entire Gulf of Mexico due to the
combination of surface high pressure, supported by a 1028 mb high
near the Florida-Georgia border, and abundant dry air in the mid-
and upper-levels of the atmosphere. The surface winds are out of
the northeast to east over the eastern and central Gulf and east 
to southeast over the western Gulf. The winds are strongest over 
the southern and western waters, but they are generally less than 
20 kt area-wide. Sea heights are highest, near 6 ft, in the Bay 
of Campeche due to the longer fetch there. Surface high pressure 
is expected to gradually shift southeastward this weekend, causing
winds to turn southerly over much of the region. This flow will 
cause sea heights to increase a little over the northwestern 
waters. Fair weather is expected to continue through the weekend 
as dry air remains in place.


Undersea volcano Kick'em Jenny, north of Grenada near 12.18N 
61.38W, is in a state of unrest. The government of Grenada advises
mariners to observe a 5 km or 3.1 nm exclusion zone around 
Kick'em Jenny. Please refer to the web page,, for 
additional information.

Tranquil conditions exist across the Caribbean Sea today with
satellite images only showing the typical patches of low clouds
and embedded quick-moving showers across the region. The remnants
of a cold front from the Windward Passage to northeastern 
Nicaragua is marked by a wind shift with northeasterly to
northerly winds west of that line and easterly flow to the east of
that old boundary. Trade winds are strongest over the south-
central waters near the coast of Colombia, and these winds are
expected to reach gale-force during the evening and overnight
hours over the next several days. See the SPECIAL FEATURES 
section above for more details. Looking ahead to the weekend, the 
remnants of the cold front is expected to dissipate, leaving the 
area in more uniform easterly flow and fair weather.


A cold front enters the discussion area near 32N58W and continues
southwestward to the Windward Passage. Scattered showers and
isolated thunderstorms are possible within 90 n mi east of the
front north of 25N. West of the front, surface high pressure
dominates the area with northerly flow and cooler air covering the
western Atlantic. Strong surface high pressure also dominates the
central and eastern Atlantic Ocean anchored by a 1034 mb high 
near 34N35W. This high is producing fresh to strong trade wind 
flow across a large portion of the tropical and subtropical 
eastern Atlantic waters. Despite the surface high pressure, there 
is an area of showers and thunderstorms from 17N to 23N between 
23W and 29W associated with an upper-level low.

The front over the central-western Atlantic is expected to slowly
shift eastward and weaken while another boundary enters the far
northwestern waters this weekend.

For additional information please visit