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Atlantic Tropical Weather Discussion



000
AXNT20 KNHC 120525
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1225 AM EST Thu Dec 12 2019

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 0000 UTC surface analysis and satellite imagery through 
0510 UTC.

...SPECIAL FEATURES...

...GULF OF MEXICO GALE WARNING...

A cold front is along 28N82.5W 26N89W. The front becomes
stationary from 26N89W to 17N94W. Expect NW-to-N gale-force
winds, and sea heights ranging from 11 feet to 17 feet in N to NE
swell, within 19N95W to 18N94W to 19N96W to 20N96W to 20N95W to
19N95W. This event is forecast to be ending during the next few
hours. Please read the latest HIGH SEAS FORECAST:
MIAHSFAT2/FZNT02 KNHC, the latest OFFSHORE FORECAST: 
MIAOFFNT4/FZNT24 KNHC, or go to the website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, everything from 
the NWS National Hurricane Center, for more details.

...ATLANTIC OCEAN GALE WARNING...
A cold front is along 31N75W 28N81W. Expect N-to-NE winds 20 to 30
knots within 29N77W to 29N81W to 31N81W to 31N76W to 29N77W. 
Frequent gusts to 35 knots are forecast N of 29.5N within 60 nm 
of the shore. The sea heights will range from 8 feet to 10 feet.
This event is forecast to last for the next 24 hours or so. Please
read the latest HIGH SEAS FORECAST: MIAHSFAT2/FZNT02 KNHC, the 
latest OFFSHORE FORECAST: MIAOFFNT3/FZNT23 KNHC, or go to the 
website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, everything 
from the NWS National Hurricane Center, for more details.

...MONSOON TROUGH/ITCZ... 

The monsoon trough passes through the coastal areas of Sierra 
Leone near 09N13W to 08N16W. The ITCZ continues from 08N16W to 
07N20W 03N30W, crossing the Equator along 40W, to the coastal
plains of Brazil near 02S45W. Precipitation: Isolated to widely
scattered moderate and locally strong are from 07N southward from
38W eastward. 

GULF OF MEXICO...

The cold front passes through Florida, about 60 nm to the north of
Lake Okeechobee, into the central Gulf of Mexico. The front is
stationary, from the central Gulf of Mexico, curving southward to
the Isthmus of Tehuantepec of southern Mexico. Expect NW-to-N
gale-force winds, and sea heights ranging from 11 feet to 17 feet
in N to NE swell, within 19N95W to 18N94W to 19N96W to 20N96W to 
20N95W to 19N95W. This event is forecast to be ending during the 
next few hours. Precipitation: scattered moderate to isolated
strong is within 210 nm to the east of the stationary front,
from 17.5N to 20.5N, in the SW corner of the Gulf of Mexico and 
in the Yucatan Peninsula. Widely scattered moderate to isolated 
strong within 75 nm to the south of the cold front between 84W and
88W. 

The current frontal boundary will stall out completely later 
tonight. The front will weaken, and move to the NW-N through
Friday night, as low pressure forms in the W central Gulf of
Mexico. This area of low pressure will move NE across the N 
central waters through early Saturday. The associated cold front 
will sweep across the eastern Gulf of Mexico through Saturday 
night. The front will leave behind a dissipating boundary across 
the far SE Gulf on Sunday. High pressure will build southward 
across the central and E Gulf of Mexico, in the wake of the front.
Fresh to strong southerly wind flow will set up in the western 
Gulf of Mexico by late Sunday. A second cold front will move into
the NW Gulf of Mexico on Monday.

CARIBBEAN SEA...

An upper level trough extends from the Atlantic Ocean near 24N65W
to 16N64W. Precipitation: Scattered moderate to isolated strong 
is within 660 nm to the east of the trough from 17N to 22N.
Comparatively drier air in subsidence covers the Caribbean Sea on
the eastern side of the trough, and elsewhere from 14N northward
between 63W and 84W.

Broad surface low pressure covers the SW corner of the Caribbean
Sea. The monsoon trough is in the eastern Pacific Ocean, from 60 
nm to 120 nm to the south of Panama. Satellite data and the GFS 
forecast for 250 mb show upper level anticyclonic wind flow in the
SW corner of the Caribbean Sea. The GFS model forecasts for 500 mb
and for 700 mb show NE wind flow in the same area. Precipitation:
isolated to widely scattered moderate and locally strong from 11N
southward from 80W westward.

The wind speeds and the sea heights will diminish across the 
region, gradually, through Friday, as high pressure in the central
Atlantic Ocean shifts eastward. The trade winds will increase 
again in the central Caribbean Sea early next week, as the surface
pressure gradient tightens. Moderate to fresh trade winds, and 
moderate N to NE swell, are expected in the Tropical N Atlantic 
Ocean, through the upcoming weekend and into early next week.

ATLANTIC OCEAN... 

A cold front passes through the Atlantic Ocean near 32N73W,
to the Florida east coast along 28N. Precipitation: broken to
overcast multilayered clouds and isolated moderate to the NW of
the line that passes through 32N70W to the Florida east coast
along 25N.

An upper level trough extends from a 33N35W cyclonic circulation
center, to a second cyclonic circulation center that is near
29N48W, to a third cyclonic circulation center that is near
26N58W, 24N65W, and eventually to 16N64W in the Caribbean Sea.
A surface trough is along 67W/68W from 24N to 31N. Precipitation:
isolated moderate to the north of the line that passes through
31N24W 26N36W 23N55W 20N66W. Rainshowers are possible also from
64W westward.

The upper level trough is along 24N65W to 16N64W. Precipitation:
Scattered moderate to isolated strong is within 660 nm to the 
east of the trough from 17N to 22N. Comparatively drier air in 
subsidence covers the Caribbean Sea on the eastern side of the 
trough, and elsewhere from 14N northward between 63W and 84W.

The current cold front will reach from 31N73W to West Palm Beach,
Florida by late tonight. The front will reach from 31N70W to 
28N76W, and stationary to West Palm Beach on Thursday. The front
will weaken gradually through Friday. Fresh to strong NE winds 
are expected N of the front, from tonight through late Thursday 
night. Large seas are expected in the waters N and NE of the 
Bahamas through early on Friday. Fresh to strong southerly winds 
will develop in the far N central waters beginning late on Friday 
night. These winds will expand eastward through Saturday night,
in advance of the next cold front that is forecast to move off 
the southeastern U.S.A. coast on Saturday. The second front will 
move quickly across the waters N of 27N through Sunday night.
Fresh to strong winds will move NE of the area on Sunday night. 
Return flow will develop early next week. 

$$
MT