[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 281155
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
655 AM EST WED DEC 28 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.

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

The Monsoon Trough reaches the coastal sections of Liberia near
05N08W, 05N16W 03N20W. The ITCZ continues from 03N20W, crossing
the equator along 26W to 01S28W, crossing the equator along 32W,
to 02N41W and 02N44W. A surface trough is along 10N41W 08N46W.
Convective precipitation: isolated moderate from 08N to 11N
between 39W and 44W. Convective precipitation with the Monsoon
Trough/ITCZ: isolated moderate to locally strong elsewhere from
08N southward from 44W eastward, and elsewhere from 05N to 10N
between 40W and 60W.

...DISCUSSION...

...THE GULF OF MEXICO...

A surface trough is in the coastal waters of the western edge of
the Yucatan Peninsula, into the eastern part of the Isthmus of
Tehuantepec. Convective precipitation: possible lingering
rainshowers from 22N southward to the Isthmus of Tehuantepec
between 92W and 96W.

A second surface trough is in the coastal waters of Mexico along
20N96W 23N97W 25N97W. Convective precipitation: Possible
lingering rainshowers are from 20N to 25N between 95W and 100W
inland.

An upper level ridge is along 95W/96W. Upper level anticyclonic
wind flow covers the SW corner of the Gulf of Mexico, from 23N
southward from 90W westward. Upper level NW wind flow covers the
rest of the area.

A 1023 mb high pressure center is near 29N87W. Surface
anticyclonic wind flow covers the Gulf of Mexico from 24N
northward between Florida and 95W.

...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: KMIS and KDLP.

IFR: KGRY.

MVFR: KXIH, KHHV, KVAF, KVQT, KGHB, KEIR, and KSPR.

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. Mostly IFR/some MVFR elsewhere.
LOUISIANA: LIFR in many areas, in the southern sections/coastal
plains. IFR/some MVFR elsewhere. MISSISSIPPI: LIFR in the coastal
plains/southernmost sections. MVFR in Natchez. IFR in Hattiesburg.
ALABAMA: LIFR in the coastal plains/southernmost sections.
LIFR in Dothan and Evergreen. MVFR in Fort Rucker. FLORIDA: LIFR
mostly, with IFR/MVFR elsewhere, from Cross City westward. LIFR at
the Tampa Executive Airport.

...THE CARIBBEAN SEA...

Upper level anticyclonic wind flow spans the entire area, with a
ridge that extends from northern Colombia beyond the Yucatan
Channel.

Comparatively drier air in subsidence is apparent in water vapor
imagery, from 70W eastward, and from 20N northward in the NW
corner of the Caribbean Sea.

24-HOUR rainfall totals in inches for the period ending at
28/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.11 in
Guadeloupe, and 0.04 in Curacao.

...HISPANIOLA...

Upper level W-to-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 the DOMINICAN REPUBLIC: Barahona: VFR/
no ceiling. Santo Domingo/La Romana/Punta Cana: VFR/no ceiling.
Santiago/Puerto Plata: VFR/no ceiling.

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 NW corner of the
Caribbean Sea to Colombia. The GFS MODEL forecast for 500 MB
shows that northerly wind flow will move across the area during
the next 48 hours, with a Gulf of Mexico-to-Cuba-to-central
Caribbean Sea ridge. It is possible that anticyclonic wind flow
also may move across Hispaniola during the next 48 hours, with
some slight variations in the orientation of the ridge. The GFS
MODEL forecast for 700 mb shows that E-to-NE wind flow will move
across the area during the first 36 hours of the 48-hour forecast
period. The wind direction will be variable during the remaining
12 hours or so, with a possible inverted trough, and some possible
anticyclonic wind flow with a ridge.

...THE ATLANTIC OCEAN...

An east-central Atlantic Ocean upper level trough is supporting a
cold front that passes through 32N28W to 27N32W and 23N37W. The
cold front is dissipating along 23N37W 22N43W 21N50W. Convective
precipitation: isolated moderate from 27N northward between 24W
and 27W. Rainshowers are possible elsewhere from 20N northward
between 23W and 74W. Rainshowers are possible elsewhere to the NW
of the line that passes 32N70W through to 27N80W.

Upper level cyclonic wind flow covers the Atlantic Ocean from 10N
to 20N between 40W and 60W. This is the area of cyclonic wind flow
that was at the SW part of the upper level trough from 24 hours
ago. Convective precipitation: isolated moderate from 28N
northward between Africa and 16W. Rainshowers are possible in the
area of cyclonic wind flow, in areas of scattered/broken low level
clouds.

Surface anticyclonic wind flow covers the Atlantic Ocean from 22N
northward between 40W and 80W, to the W and NW of the cold front.
A 1028 mb high pressure center is near 32N52W.

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

$$
MT
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