000
AXNT20 KNHC 271701
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1201 PM EST Wed Dec 27 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.

...ITCZ/MONSOON TROUGH... 
The monsoon trough enters the Atlantic Ocean through Liberia,
Africa and continues to near 05N10W. The Intertropical Convergence
Zone axis extends from 05N10W to 03N20W to 05N35W to the Equator 
near 52W. Scattered moderate convection is from 01N-06N between 
27W-41W.

...DISCUSSION...

GULF OF MEXICO...
A weak low pressure persits across the north-central Gulf and now
is located near 29N90W. A cold front extends from the low center
to just S of Brownsville, Texas into NE Mexico and along the Rio
Grande River valley. A stationary front will also extends eastward
from the low center to across northern Florida, with a warm front
sector between the low and 86W. Mainly low-level clouds with 
embedded showers, and patches of fog are noted in the vicinity of 
the low/front. The pressure gradient between the low/front and 
strong high pressure N of area is resulting in fresh to strong 
NE-E winds behind the frontal boundary. The remainder of the basin
is under the influence of a surface ridge extending from the SE 
CONUS. The ridge is providing gentle to moderate E-SE winds S of 
the frontal boundary, with the exception of moderate to locally 
fresh NE-E winds near the Yucatan Peninsula likely associated with
the thermal trough. The low will shift E to near 27N88W this 
evening, then weaken to a trough tonight that will meander along 
86W through early Fri before losing identity. The cold front will 
move southward across the Gulf waters through Thursday night while
gradually dissipate. High pressure will build in in the wake of 
the front. Looking ahead, the next strong cold front is expected
to emerge off the Texas and Louisiana coasts Sunday evening 
followed by strong to gale-force winds and building seas of up to 
14-15 ft.

CARIBBEAN SEA...
The most recent scatterometer data show moderate to fresh winds 
across the south-central Caribbean near the coast of Colombia, 
while moderate to fresh winds prevail across the remainder of the
Caribbean. Patches of low-level moisture embedded in the trade 
wind flow are producing isolated to scattered passing showers 
across the Greater and Lesser Antilles from time to time. Little 
change in this weather pattern is expected during the next couple 
of days. Expect strong to near gale force nocturnal winds near 
the coast of Colombia tonight. Strong NE winds then expected along
the NW coast of Colombia during the overnight and early morning
hours through the upcoming weekend. E swell currently across the 
tropical Atlantic waters, including the E Atlantic passages, will
begin to subside from the NE on Thu.

...HISPANIOLA...
Isolated to scattered showers carried by the trade winds will 
continue to affect the island from time to time. Mostly dry and 
stable conditions are expected to persist during the next couple 
of days under the influence of a mid to upper-level ridge and 
associated strong subsidence. A larger patch of moisture may 
cross the island Thursday night into Fri, slightly increasing the
likelihood of showers.

ATLANTIC OCEAN...
A cold front enters the discussion area near 31N59W extending SW 
to 30N62W, and becoming stationary to near the NW Bahamas. Mainly
low clouds with embedded isolated showers are occurring along the
frontal boundary. The stationary front will lift N as a weak warm 
front today with a surface low developing near 31N79W by early 
Thu. The low will move NE dragging a new cold front SE through the
Central Bahamas by Fri. Another surface low will develop near 
29N78W on Thu night, and race E-NE passing N of Bermuda on Fri 
night. In fact, a recent scatterometer pass hints the formation 
of a low across the front near 29N74W. The remainder of central 
and eastern Atlantic is under the influence of a surface ridge 
anchored by a 1033 mb high centered S of the Azores near 34N28W.
The pressure gradient between this high and lower pressure in the
vicinity of the ITCZ/monsoon trough is resulting in a large area 
of fresh to strong winds between the coast of Africa and the 
Lesser Antilles, with seas of up to 11-12 ft. The high pressure
will move E and weaken some over the next 24 hours.

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

$$
GR