[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 082347
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
647 PM EST Wed Feb 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 1800 UTC surface analysis and satellite imagery through
2315 UTC.

...CARIBBEAN GALE WARNING...

A gale warning is in effect within about 90 nm of the coast of
Colombia. The pressure gradient between high pressure north of the
region and the Colombian/Panamanian low will continue to support
fresh to strong trades over the south-central Caribbean during the
next several days. Winds will pulse to gale force within about 90
nm of the coast of Colombia during the overnight and early
morning hours. Model guidance shows seas building to 8 to 12 ft
over the region with the strongest winds. See latest NWS High
Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for
more details.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough enters the Atlantic Ocean through the coast of
Liberia near 06N10W to 05N13W. The ITCZ continues from 05N13W to
05N22W to 01N30W to the Equator at 40W. Scattered moderate isolated
strong convection is over SE Liberia and coastal waters, and from
02.5N-04N between 09N-13N. Similar convection is from 01N-02N
between 17W-19W. Scattered moderate convection can be found within
abouth 60 nm SE of a line from 06n14W to 05N17W to 02N21W. Scattered
moderate convection is also from the Equator to 03N between 25W
and 31W.

...DISCUSSION...

...GULF OF MEXICO...

A ridge dominates the entire Gulf region. Under the influence of
this system, mostly fair weather prevails. Latest observations
indicate the development of patches of fog over the coastal
waters W of 87W due to a moist and warm air spreading over
relatively cooler waters. Gentle to moderate southwesterly winds
are noted over the north Gulf north of the ridge axis while SE-S
winds are seen elsewhere south of the ridge axis. The ridge will
weaken tonight as a cold front moves across the NW waters.
Currently, Doppler Radar shows a band of showers, with embedded
thunderstorms over the Florida Panhandle ahead of the front. This
system will move quickly across the Gulf, reaching from central
Florida to northeast Mexico Thursday morning, and pushing through
south Florida during the afternoon hours. Fresh to strong northerly
winds are expected in the wake of the front, with seas building
to 6-8 ft. Winds are forecast to quickly veer to the NE-E by
Thursday night as the high pressure behind the front moves east
over the eastern United States. By late Friday, the high pressure
will move into the western Atlantic, extending a ridge across the
Gulf region. As a result, southerly return flow will set up over
the western Gulf. Aloft, mainly a NW flow is noted across the
Gulf.

...CARIBBEAN SEA...

A gale warning is in effect for the south-central Caribbean.
Please, see Special Feature section for details. Scatterometer
data provided observations of moderate to fresh winds across the
remainder of the east and central Caribean. Lighter winds are
noted over the NW Caribbean. A fast moving cold front will reach
western Cuba and the NW Caribbean by Thursday evening with some
shower and thunderstorm activity, then the front will move across
the remainder of Cuba on Friday while gradually weaken across the
Caribbean Sea. As high pressure, in the wake of the front, moves
eastward Friday through Saturday, expect increasing northeasterly
winds across Cuba and in the lee of the island, including also the
Windward Passage. Shallow moisture embedded in the trade windflow will move across the region producing isolated to scattered
passing showers. Aloft, a westerly flow prevails across the basin
with strong upper level subsidence and implied dry air mass.

...HISPANIOLA...

Moisture associated with an exiting trough north of Hispaniola
will support a few light showers across the island. By late
Friday, an approaching frontal boundary will increase the
likelihood of showers.

...ATLANTIC OCEAN...

High pressure centered near 36N42W extends a ridge across the
majority of the forecast area. Winds have increase to 20-30 kt
just E of NE Florida due to the pressure gradient between the
ridge and a low pressure located near Cape Hatteras. South of the
ridge, mainly fresh trade winds are noted across the central
Atlantic, particularly south of 20N, and E of the Lesser Antilles.
These winds are expected to persist on Thursday, affecting mainly
the tropical Atlantic between the Cabo Verde Islands and 55W as
the high pressure shifts eastward to a postion near 36N35W. A
band of moderate convection is ahead of trough extending from
31N71W to 27N73W. This trough is a reflection of mid-level trough
moving eastward across the ocean north of Hispaniola, causing the
ridge to retreat eastward. A frontal trough stretches from 31N34W
to 26N51W with low-topped showers. A stronger cold front will
move rapidly across the western Atlantic on Thursday, and reach
from 31N61W to the SE Bahamas and eastern Cuba by Fri morning.

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

$$
GR
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