Tropical Weather Discussion
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000
AXNT20 KNHC 161044
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
644 AM EDT Mon Apr 16 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 0600 UTC surface analysis and satellite imagery through
1030 UTC.

...SPECIAL FEATURES...

...Atlantic Gale Warning...

A cold front has moved off the coast of Florida, reaching from
31N78W to Miami then on to near Havana Cuba. Scattered
thunderstorms were ahead of the front, although they are currently
weakening. Gales are likely ongoing north of 30N both ahead of
and following the frontal boundary. Gale conditions were confirmed
by three ship reports in this area. Buoy 41010 near 29N78.5W has
stayed just below gale, helping identify the southern boundary of
gale force winds. Seas north of the Bahamas and off northeast
Florida are likely 10 to 15 ft currently. Winds will diminish
below gale force early this morning as the main supporting upper
dynamics lift northeast of the area. For more details, please
refer to the High Seas Forecast under AWIPS/WMO headers
HSFAT2/FZNT02 KNHC.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains of western
Africa near 09N13W to 04N20W. The ITCZ continues from 04N20W to
01N50W. No significant convection is noted.

...DISCUSSION...

...GULF OF MEXICO...

Fresh to strong NW winds persist over the eastern Gulf following
a late season cold front currently sweeping east of the basin.
Buoy and scatterometer data show fresh to strong W to NW winds
over the northeast Gulf, with seas to 11 ft. 1024 mb high
pressure is building over the western Gulf, allowing seas to
diminish to light to moderate. However northerly swell to 8 ft
lingers, mainly over the southwest Gulf. This should decay to 5 to
7 ft through this morning.

Overall winds and seas will diminish from west to east across the
Gulf through Mon as high pressure continues to build over the
northern Gulf. The high pressure will shift westward across the
northern Gulf through mid week. Southerly return flow will
increase over the northwest Gulf Tue into Wed as the ridge shifts
east. A weaker cold front will drift into the northern Gulf Thu
then stall and dissipate through Fri.

...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...

Fresh to strong northerly winds follow a cold front
moving into the northwest Caribbean. A line of showers is ahead
of the front, with thunderstorms ongoing off the coast of
Honduras. Fresh to strong winds and seas to 9 ft are noted over
the south central Caribbean, with moderate to fresh trade winds
and 4 to 6 ft seas elsewhere. No significant convection is noted
elsewhere throughout the Caribbean.

The winds and seas will subside as the front stalls then
dissipates from eastern Cuba across the Caymans to central
Honduras through mid week. Strong high pressure in the central
Atlc along with ridging into the northern and eastern Caribbean
will continue to support fresh to strong E to NE winds along the
coast of Colombia and the Gulf of Venezuela through Fri.

...SW N ATLANTIC INCLUDING THE BAHAMAS...

Please see Special Features section for more information on the
Atlantic gale warning.

Elsewhere west of 60W, an earlier scatterometer satellite pass
along with a concurrent altimeter satellite pass showed strong E
winds and seas to 8 ft off the north coast of Haiti and near the
approaches to the Windward Passage. These winds are diminishing as
the supporting ridge northeast of the region shift farther east
ahead of the advancing front. Over the remainder of the area,
moderate to fresh E to SE winds persist, with 5 to 7 ft seas north
of 22N and 6 to 8 ft seas south of 22N in part due to NE and E
swell.

Winds and seas will diminish through Tue north of 25N as the
front shifts east and reaches from Bermuda to eastern Cuba by
late Tue, before lifting north to 25N and dissipating through
Thu. A weak front will sag southward into the waters off
northeast Florida Fri before stalling and dissipating.

Over the central Atlantic, surface ridging prevails across the
central Atlantic anchored by a 1028 mb high near 33N57W,
maintaining moderate to fresh trade winds in the deep tropics
south of 35W. NE to E swell of 8 ft persists south of 15N, but
will decay to less than 8 ft over the next 24 hours.

Farther east, the subtropical ridge shifted eastward ahead of a
cold front is moving through the Azores into the eastern Atlantic.
This is maintaining generally moderate trades farther south. The
lack of significant trade wind convergence or upper level support
is resulting in little active convection along the monsoon trough
or ITCZ. The front will be accompanied by a large area of NW
swell with wave heights of 8 to 15 ft covering much of the area
north of 20N and east of 45W through at least Thu.

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

$$
Christensen



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