[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 081736
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1236 PM EST SUN JAN 8 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...SPECIAL FEATURES...

ATLC GALE WARNING...

A cold front extends from 31N68W across the central Bahamas and
central Cuba into the Caribbean Sea. A very strong high pressure
center of 1043 mb follows the front, producing a very tight
pressure gradient across the western Atlantic and Florida. The
most recent scatterometer data provided observations of gale force
winds behind the front, while a pair of altimeter passes indicated
seas of 13-14 ft in association with these winds. Winds are
forecast to diminish below gale force early this afternoon. Fresh
to strong Northerly winds are expected behind the front during the
next 24-48 hours. The front is forecast to reach a position from
Bermuda to eastern Cuba later today. Winds will begin to gradually
diminish across the waters E of north and central Florida Monday
and Monday night as the strong high pressure center in the wake of
the front moves toward the Carolinas into the western Atlantic.
See latest NWS High Seas Forecast under AWIPS/WMO headers
MIAHSFAT2/FZNT02KNHC for more details.

GULF OF MEXICO GALE WARNING...

Strong pressure gradient across the SW Gulf of Mexico, associated
with a 1040 mb high pressure over eastern Mexico near Tampico,
continues to support minimal gale force winds S of 20N W of 95W,
where seas are in the 13-18 ft range. Winds are forecast to
diminish below gale force early this afternoon. See latest NWS
High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC
for more details.

CARIBBEAN GALE WARNING...
The aforementioned cold front continues SW from central Cuba to
the Gulf of Honduras. Fresh to strong northerly winds are noted in
the wake of the front based on scatterometer and surface
observations. The front is forecast to reach a position from
Hispaniola to the coast of Nicaragua near 13N83W by Monday
morning. Winds are forecast to further increase to minimal gale
force across the Windward Passage, the waters between Jamaica and
Haiti and beyond across the central Caribbean to near 15N78W by
Monday morning. These conditions are expected to persist to at
least Tuesday morning. See latest NWS High Seas Forecast under
AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends from the African coast near 09N13W to
07N19W. The Intertropical Convergence Zone axis continues from
07N19W to 05N28W to the coast of South America near 02S43W.
Scattered moderate to isolated strong convection is from 00N- 04N
between 00W-13W. Isolated moderate convection is from 00N-05N
between 24W-30W.

...DISCUSSION...

GULF OF MEXICO...

A very strong high pressure center of 1043 mb over the SE CONUS
extends a ridge across Florida, the entire Gulf of Mexico and
eastern Mexico, where a 1040 mb high pressure is also noted near
Tampico. Under the influence of the ridge, fresh to strong
northerly winds are observed across the Gulf region with the
exception of gale force winds across the SW Gulf. See Special
Features for details. Cold air stratocumulus clouds, parallel to
the wind direction, covers most of the Gulf waters. Persisting
low cloudiness are banked up along the eastern slopes of the
Sierra Madre mountains. Outside of the gale area, winds are
northerly 20-30 kt with seas of 13-14 ft. The high pressure will
slide eastward through Thursday while weakening. Winds are forecast
to diminish across the Gulf from W to E through Tuesday. Strong
cold air advection is expected to continue for the next 24 hours.
In the upper levels, a trough extends from northern Florida to the
SW Gulf. Strong subsidence and implied dry airmass is over the
entire Gulf.

CARIBBEAN SEA...

A cold front is over the Caribbean Sea and extends from central
Cuba to the Gulf of Honduras. See Special Features for details.
The front is generating scattered showers and isolated thunderstorm
over the Gulf of Honduras. High pressure over the central Atlantic
combined with the Colombian/Panamanian low supports fresh to strong
trades across the south-central Caribbean. A recent scatterometer
pass confirmed the presence of these winds and also indicated
fresh to strong northerly winds in the lee of eastern Cuba.
Moderate to locally fresh trade winds are noted elsewhere. An area
of cloudiness with embedded showers is over the SW Caribbean
affecting parts of Nicaragua and Costa Rica. A diffluent pattern
aloft is helping to induce this convective activity. Shallow
moisture embedded in the trade wind flow will continue to move
across the basin producing isolated to scattered passing showers.
In the upper levels, a ridge is over the E Caribbean with axis
along 65W. SW flow, on the west side of the ridge, is advecting
mid-upper level moisture from the EPAC across the western half of
the Caribbean Sea.

...HISPANIOLA...

Moisture is forecast to increase across the island tonight and
Monday ahead of a cold front currently moving across eastern Cuba.
As a result, expect increasing shower activity with the potential
of a few thunderstorms and gusty winds.

ATLANTIC OCEAN...

A cold front is moving across the western Atlantic and stretches
from 31N68W across the central Bahamas and central Cuba into the
Caribbean Sea. See Special Features for details. Visible satellite
imagery shows an impressive and very well defined 240 nm wide-band
of cloudiness with embedded showers and scattered thunderstorms
in association with this front. Cold air stratocumulus clouds are
behind the frontal boundary. A 1029 mb high pressure is ahead of
the front, over the central Atlantic near 35N42W and extends a
ridge SW to near the Turks and Caicos Islands. Farther east, there
is a low pressure of 1011 mb near 30N26W. A trough extends from
the low center to near 20N30W. The low is forecast to move
westward and open up into a trough in about 24-36 hours. The
pressure gradient between the low and the high pressure is
producing an area of fresh to strong northerly winds particularly N
of 24N between the low and about 40W based on a recent ASCAT pass.
Some shower and thunderstorm activity is noted on the NE quadrant
of the low center.

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

$$
GR
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