[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271200
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
700 AM EST TUE DEC 27 2016

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 0600 UTC surface analysis and satellite imagery through
1115 UTC.

...SPECIAL FEATURE...

Please refer to the METEO-FRANCE High Seas Forecast, that is
listed under the following links: MARINE...BULLETINS
EXPERTISES...GRAND LARGE...METAREA II...or on the website:
WWW.METEOFRANCE.COM/PREVISIONS-METEO-MARINE/BULLETIN/
GRANDLARGE/METAREA2. Gale-force winds are forecast for the area
that is called: IRVING. The OUTLOOK, for the 24 hours that follow
the forecast that is valid until 28/1200 UTC, consists of: the
persistence of a cyclonic gale or near gale in IRVING.

...THE ITCZ/THE MONSOON TROUGH...

The Monsoon Trough reaches the coastal sections of Liberia near
06N10W to 04N16W. The ITCZ continues from 04N16W to 02N24W 02N32W
02N40W. The surface trough of six hours ago has weakened and
dissipated. Convective precipitation: widely scattered moderate to
isolated strong from 01N to 07N from 20W eastward, and from 07N
southward between between 20W and 36W. Isolated moderate elsewhere
from 10N southward from 60W eastward. High level clouds are to the
south of 27N15W 26N22W 19N40W 16N50W 15N60W, moving
northeastward.

...DISCUSSION...

...THE GULF OF MEXICO...

A surface trough is along 92W/93W from 17N in the Isthmus of
Tehuantepec to 23N in the SW corner of the Gulf of Mexico.
Convective precipitation: scattered moderate to isolated strong
from 17N to 21N between 95W and 96W.

The easternmost 20 percent of the area is covered with upper level
anticyclonic wind flow. This anticyclonic wind flow is part of the
larger-scale upper level ridge that is in the Caribbean Sea.

An ill-defined upper level trough passes through the eastern part
of the Gulf of Mexico, from 90W eastward.

A separate area of upper level anticyclonic wind flow is moving
from interior sections of Mexico into the central Gulf of Mexico.

A surface ridge passes through the Florida Panhandle, to the middle
Texas coastal waters/deep south of Texas, into the SW corner of
the Gulf of Mexico.

Convective precipitation: Rainshowers are possible from 90W
eastward, from 23N southward from 90W westward, from 88W
eastward, and from 25N northward from 90W westward, in areas of
scattered/broken low level clouds.

...LOW LEVEL CLOUD CEILINGS AND WEATHER FOR THE OFFSHORE OIL
PLATFORM SITES THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N
NORTHWARD AND FROM 88W WESTWARD...

LIFR: KBBF, KBQX, KXIH, KGRY, and KDLP.

IFR: KHHV, and KSPR.

MVFR: KMZG, KVAF, KEMK, KEIR, and KVQT.

LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF
THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

TEXAS: LIFR, nearly everywhere, from the Lower Rio Grande Valley
to Houston and to Huntsville, and from Galveston to Beaumont/Port
Arthur and Jasper. LOUISIANA: LIFR, pretty much everywhere, in
the southern sections/coastal plains. MISSISSIPPI: IFR from
Natchez-to-Hattiesburg. LIFR in the coastal plains/southernmost
sections. ALABAMA: LIFR, mostly, from Dothan and Evergreen
southward. FLORIDA: LIFR from Cross City westward, at the Tampa
Executive Airport, and in Punta Gorda.

...THE CARIBBEAN SEA...

Upper level anticyclonic wind flow, from South America and Central
America, toward the north and northeast, is related to an upper
level ridge that extends from northern Colombia beyond NW Cuba.

Comparatively drier air in subsidence is apparent in water vapor
imagery, to the north and northeast of the line that passes
through La Peninsula de la Guajira of northern Colombia, to the
eastern coast of Jamaica, beyond NW Cuba. Upper level NE wind flow
has been pushing the comparatively drier air into this part of
the Caribbean Sea.

Upper level southerly wind flow covers the area that is from 80W
westward, in the area of upper level anticyclonic wind flow, with
the Colombia-to-NW Cuba ridge. Convective precipitation: isolated
moderate from 18N southward from 80W westward, in the coastal
waters and coastal plains of Central America. It is possible that
speed convergence may be a contributing factor to the
precipitation.

The monsoon trough is along 09N between 73W and beyond 84W in
Costa Rica. Convective precipitation: isolated moderate from 11N
southward from 76W westward.

24-HOUR rainfall totals in inches for the period ending at
27/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.19 in
Curacao, and 0.13 in Guadeloupe.

...HISPANIOLA...

Upper level NW wind flow is moving across Hispaniola.
Comparatively drier air in subsidence is apparent in water vapor
imagery, across the entire area. Convective precipitation:
Rainshowers are possible across Hispaniola, and in the coastal
waters and coastal plains, in areas of broken low level to middle
level clouds.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR/no
ceiling. for the DOMINICAN REPUBLIC: Barahona: VFR. Santo
Domingo/La Romana/Punta Cana: VFR/no ceiling. Santiago: light
rain. MVFR. ceiling 1200 feet. Puerto Plata: MVFR. ceiling 1600
feet.

The GFS MODEL forecast for 250 MB shows that NW wind flow will
move across the area during the next 48 hours. A NW-to-SE oriented
ridge is forecast to be along the line from the Yucatan Channel to
Colombia. The GFS MODEL forecast for 500 MB shows that NE wind
flow will move across the area during the next 48 hours, with a
Gulf of Mexico-to-central Caribbean Sea ridge. The GFS MODEL
forecast for 700 mb shows that NE wind flow will move across the
area during the next 48 hours. It is possible that an inverted
trough may move across Hispaniola during each day of the two-day
forecast period.

...THE ATLANTIC OCEAN...

A central Atlantic Ocean upper level trough is supporting a cold
front that 32N40W to 29N44W and 27N50W. Convective precipitation:
isolated moderate within 90 nm on either side of 25N44W 28N40W
beyond 32N36W. Rainshowers are possible elsewhere from 23N
northward between 32W and 74W.

An upper level trough extends from 32N26W to 25N35W 19N48W and
14N60W. Convective precipitation: isolated moderate from 28N
northward between Africa and 16W. Rainshowers are possible within
250 nm on either side of 32N27W 24N34W 16N41W 15N60W.

A surface ridge passes through 32N20W to 28N26W 23N47W, to the
east of the cold front. Surface anticyclonic wind flow covers the
Atlantic Ocean from 20N northward between 51W and 79W, to the west
of the cold front.

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

$$
MT
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