[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 071744
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1244 PM EST Sun Jan 7 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
1745 UTC.

...SPECIAL FEATURES...

...Atlantic Gale Warning...

Strong high pressure of 1040 mb building SE toward the U.S.
Atlantic coast supports strong to gale-force northeast winds
mainly south of 25N and west of a stationary front that currently
extends from 31N55W to 25N65W to 20N73W. Gale force winds will
also develop across the Windward Passage overnight. Seas are
forecast to build to 10-13 ft within the area of gale-force
winds. Fresh to strong NE winds are expected to also affect the
remainder of the waters between the Bahamas and Cuba, and the
Straits of Florida with seas up to 12 ft outside the Bahamas.
Conditions across the region will improve Mon night as the high
shifts east and weakens and the front dissipates. See the latest
NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02
KNHC for more details.

...Caribbean Gale Warning...

The aforementioned high pressure is also currently bringing
strong to gale-force northeasterly winds in the lee of east-
central Cuba, including the Cayman Islands as indicated by a
recent scatterometer pass. These conditions will continue through
this afternoon. Gale winds will then become confined to the
Windward Passage and approaches to the passage north of 16N and
west of the stationary front to 76W by tonight. Seas are forecast
to build to 10-12 ft near the Cayman Islands. See the 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 from the Africa coast
near 08N13W and continues to 03N23W. The Intertropical Convergence
Zone extends from 03N23W to 00N42W. Scattered showers are within
120 nm on either side of the ITCZ between 26W-42W.

...DISCUSSION...

GULF OF MEXICO...

A ridge dominates the basin anchored by a strong high pressure of
1040 mb located near 37N78W. To the southwest, a surface trough
extends from 26N93W to 23N92W. The pressure gradient between the
high pressure to the north and lower pressures over the Caribbean
support fresh to strong easterly winds over the Straits of
Florida and eastern half of the basin. Mainly moderate to fresh
easterly winds prevail elsewhere. Expect for the next cold front to
emerge off the Texas and Louisiana coasts on Monday, followed by
mainly fresh northerly winds and building seas of 5-6 ft. The
front and associated winds will weaken on Tuesday.

CARIBBEAN SEA...

A stationary front extends across the Windward Passage near 20N75W
to 12N81W. Clusters of moderate convection are noted along the
the frontal boundary mainly north of Jamaica. Latest scatterometer
data indicated that strong to gale-force winds are now occurring
over the Lee of Cuba, while fresh to strong winds are occurring
across the Windward Passage and the south-central Caribbean near
the coast of Colombia. The stationary front will slowly weaken
during the next few days. Strong high pressure building southeast
toward the U.S. Atlantic coast will continue supporting the gale-
force winds between Jamaica, the lee of Cuba and the Windward
Passage and approaches. Please see the Special Features section
for more details.

...HISPANIOLA...

The region is between a stationary front through the Windward
Passage and a surface trough approaching from the southeast.The
moisture from these two features will support showers and
thunderstorms over the island through Monday. High pressure
building to the north will support 20 to 30 kt NE winds over the
northern coast of Haiti this afternoon and tonight.

ATLANTIC OCEAN...

A stationary front enters the area of discussion near 31N55W and
extends to 20N73W. Scattered moderate convection is noted within
390 nm west of the front. The pressure gradient between strong
high pressure over eastern U.S. and the stationary front supports
20 to 30 kt NE winds and seas of 7 to 10 ft in unprotected waters
south of 25N and west of the front. To the east, a 1031 mb surface high
centered near 32N36W supports a broad area of fresh to strong
easterly trades south of 23N over the central and eastern
Atlantic. The combination of these winds and a northwest swell
from a departing storm system over the northern Atlantic supports
seas of 8 to 14 ft over the majority of the Atlantic discussion
waters between the Cabo Verde Islands and 75W. Higher seas of 12
to 18 ft are occurring N of the Cabo Verde Islands under strong
northerly winds on the eastern periphery of the Atlantic high
pressure. The surface high over eastern U.S. will shift east
through tonight and will increase the pressure gradient just west
of the stationary front. This will result in gale-force winds
developing over the Windward Passage and approaches later. Please
refer to the Special Features section for more details.

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

$$

ERA

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