[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251711
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
105 PM EST Wed Jan 25 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
1645 UTC.

...SPECIAL FEATURES...

...Atlantic Gales...

A cold front enters the discussion area near 32N56W and
continues SSW to Virgin Islands near 19N64W. North of 25N within
180 nm east of the front south to southwest winds 30 to 35 kt
are occurring.  North of 29N east of 63W to the front, northwest
winds 30 to 35 kt are also found.  The south to southwest gales
ahead of the front should continue until 1200 UTC Friday, while
the northwest gales behind the front should weaken by 1200 UTC
Thursday.  See the latest NWS High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 KNHC for more details.

...Gulf of Mexico Gale...

A cold front currently over southeastern Texas will reach the
Gulf of Mexico later today. As high pressure builds in,
northwest to northeast winds will build in behind the front
extending from 30N84W to 25N91W to 19N97W by 1200 UTC Thursday.
South of 21N west of 95W - near Veracruz - northwest to north
winds of 30 to 35 kt are expected at that time and are likely to
remain in place through 0000 UTC Friday.  See the latest NWS
High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC
for more details.

...ITCZ/MONSOON TROUGH...

The Intertropical Convergence Zone axis extends from the African
coast near 06N10W to 03N25W to the South American coast near
01S45W.  There is no oceanic monsoon trough this morning.
Scattered moderate convection is from 01N-05N between 22W-50W.

...DISCUSSION...

GULF OF MEXICO...

A 1005 mb low is centered along the southern Texas coast near
27N97W with an attached trough extending east-northeast
paralleling and just offshore Texas and western Louisiana.  The
feature is identified as a "Trough" on the surface map, but it
may instead be considered a undular bore.  This low-level cloud
feature - not associated with any hazardous winds or
precipitation - should dissipate later today.  Winds across the
Gulf are generally 10-20 kt southeasterlies south of 27N and 15-
25 kt southwesterlies north of 27N.  A cold front currently over
southeastern Texas will reach the Gulf of Mexico later today. No
deep convection is expected ahead or along the front, though
scattered showers are likely within 30 nm of the front.  As high
pressure builds in, northwest to northeast winds of generally 20-
30 kt will occur behind the front extending from 30N84W to
25N91W to 19N97W by Thursday morning.  Northwest to north gale
conditions are also expected for the area near Veracruz starting
Thursday morning.  See Gulf of Mexico Gale section above for
more details.  The weakening cold front should extend across the
southern Gulf from 25N81W to the Yucatan peninsula by Friday
morning with gradually diminishing winds.

CARIBBEAN SEA...

The tail end of a cold front extends southwestward from the
Virgin Islands to just south of the Mona Passage at 17N68W. From
that point, a surface trough extends southwestward across the
Caribbean to 12N81W.  A second trough exists in the eastern
Caribbean from 18N63W to 12N68W.  No significant deep convection
is associated with the front/troughs, though scatted showers are
likely within 60 nm of the front/troughs.  With only a weak
north-south pressure gradient over the Caribbean, winds are only
5-10 kt, generally out of the east.  The front/troughs should
dissipate by Friday, with high pressure building in north of the
Caribbean causing the tradewinds to reach a more normal 10-20 kt
with winds to 30 kt just north of Colombia.

...HISPANIOLA...

The proximity of the front and trough near the Mona Passage has
resulted in broken to overcast low clouds with scattered showers
over eastern Dominican Republic. Some low clouds and widely
scattered showers are also occurring elsewhere in Hispaniola in
the northward facing elevated terrain.  The cold front/tough
should dissipate by Friday, reducing the changes of showers.

ATLANTIC OCEAN...

A vigorous cold front enters the discussion area near 32N56W and
continues SSW to Virgin Islands near 19N64W. Gales exist both
east and west of the front. See Atlantic Gales feature above for
more details.  Scattered to numerous showers extend within about
240 nm east of the front north of 25N and about 120 nm east of
the front south of 25N.  A weak 1019 mb surface high is located
between Cuba and the northwestern Bahamas.  The cold front and
the high should quickly move eastward due to a progressive upper-
level pattern during the next two days.  Elsewhere a second
frontal boundary enters the northern boundary in the eastern
Atlantic near 32N25W and is draped westward to 30N37W to 32N42W.
 A pre-frontal trough is also present from 32N25W to 26N43W.
Scattered showers are likely within 60 nm of the front and the
trough.  Southwesterly winds ahead of the front are 15-25 kt.
The front/trough should push eastward and move out of the
Atlantic on Thursday.  A new cold front will push off of the
southeastern United States on Thursday afternoon.  Southwesterly
winds ahead of the front should reach 20-30 kt, with
northwesterly winds reaching only 10-20 kt behind the front.

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

$$
Landsea
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