Tropical Weather Discussion
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000
AXNT20 KNHC 171709
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1209 PM EST Wed Jan 17 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
1715 UTC.

...SPECIAL FEATURES...

...Gulf of Mexico Gale Warning...

A strong cold front continues to move across the Gulf region. As
of 1200 UTC, the front extends from a 1023 mb low pressure over
South Carolina across northern Florida into the Gulf of Mexico to
near 24N90W to Veracruz, Mexico. Gale force winds are occuring
west of the front S of 26N based on latest scatterometer pass. A
recent altimeter pass indicates seas of 16-18 ft within the area
of gale force winds. The front will move south of the basin
tonight. Gale force winds are expected west of the front along the
coast of Mexico near Veracruz through tonight. Fresh to strong
northerly winds are also expected elsewhere behind the front
through tonight. High pressure behind the front will slowly shift
eastward along the US Gulf coast through Friday. Please read the
latest NHC High Seas Forecast under AWIPS/WMO headers
MIAHSFAT2/FZNT02 KNHC, and the latest NHC Offshore Waters
Forecast, MIAOFFNT4/FZNT24 KNHC, for more details.

...Atlantic Gale Warning...

The low pressure currently located over South Carolina will move
ENE into the western Atlantic Ocean while deepening. This will
induce a band of gale force winds north of 30N on Thursday behind
the strong cold front forecast to move off Florida this afternoon,
and extend from 31N69W to eastern Cuba Thu, then weaken SE of the
Bahamas from 24N65W to the Windward Passage on Fri. Strong high
pressure behind the front will bring strong winds and high seas NE
of the Bahamas Wed through Thu night. Please read the latest NHC
High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC,
and the latest NHC Offshore Waters Forecast, MIAOFFNT3/FZNT23
KNHC, for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic Ocean through Sierra Leone,
Africa and continues to 01N21W. The ITCZ extends from 01N21W to
02N40W to the Equator at 50W. Scattered moderate convection is
observed within about 120 nm N of the ITCZ between 30W-40W.
Similar convection is from 03N-04.5N between 42W-47W.

...DISCUSSION...

...GULF OF MEXICO...

A strong cold front is moving across the Gulf region. See the
Special Features section for more details. A band of multi-layer
clouds with embedded showers is associated with the front followed
by cold air stratocumulus clouds forming parallel to the wind. A
ridge dominates the remainder of the Gulf waters. Fresh to locally
strong southerly flow will set-up across the western Gulf by Fri,
and persist on Saturday ahead on the next cold front forecast to
reach the Texas coast Sun night.

...CARIBBEAN SEA...

A dissipating stationary front remains across the basin extending
from eastern Cuba to near 17N80W. Abundant cloudiness with
embedded showers and tstms are noted over the NW Caribbean and a
surface trough is analyzed there extending from 21N86W to 15N82W
at 1500 UTC. According to the Galvez-Davison Index (GDI), there is
a potential for widespread shallow convection across the NW
Caribbe and parts of Nicaragua and Honduras today. Abundant
moisture will persist over this area through Thursday based on the
GFS model. Patches of low-level moisture carried by the trade
wind flow are seen across the remainder of the Caribbean Sea.
Moderate to fresh NE winds are seen in the lee of Cuba, and within
about 60 nm of the coast of Nicaragua. Fresh to strong winds are
near the coast of Colombia. The cold front currently moving across
the Gulf of Mexico will reach the NW Caribbean tonight, then
extend from central Cuba to Honduras on Thursday. Fresh to strong
winds and widespread showers are expected behind the front through
Thursday night. Strong trade winds will pulse near the coast of
Colombia coast Fri night and then expand across much of the
central Caribbean over the weekend as high pressure builds N of
area.

...HISPANIOLA...

Relatively dry weather with partly cloudy skies and isolated
showers will prevail for the next day or so over the island due
to the influence of a ridge. Computer models show increasing
moisture across Hispaniola toward the end of the work-week as a
cold front approaches from the west. Fresh NE winds are expected
across the Windward Passage Thursday through Saturday night as
high pressure builds across the western Atlantic in the wake of
the above mentioned front.

...ATLANTIC OCEAN...

A weakening stationary front extending from 31N66W to eastern
Cuba will dissipate later today. A strong cold front will move off
Florida this afternoon, and extend from 31N69W to eastern Cuba
Thursday, then weaken SE of the Bahamas from 24N65W to the
Windward Passage on Friday. See Special Features section for more
details. An upper-level low is reflected at the surface as a
trough that extends from 31N46W to 24N47W. Scattered showers and
tstms are associated with this low/trough covering mainly the
waters N of 28N between 42W-45W. An area of fresh to strong E-SE
winds in noted E of the trough due to the pressure gradient
between the trough and a 1037 mb high pressure located near the
Azores at 40N25W. The trough will drift westward over the next 24
hours. The strong high pressure near Azores dominates most of the
east and centarl Atlantic, and will move little through Thursday.

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

$$
GR




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