[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 290605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
105 AM EST THU DEC 29 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 0000 UTC surface analysis and satellite imagery through
0515 UTC.

...SPECIAL FEATURES...

...Gulf of Mexico Gale Warning...

The 18-hour forecast consists of: a cold front from 30N84W TO
25N97W. to the north of the front: N to NE winds 20 to 30 knots,
with frequent gusts to 35 knots to the north of 26N to the west of
94W. Sea heights less than 8 feet, except sea heights to 10 feet
to the north of 26N to the west of 95W. Please read the High Seas
Forecast under AWIPS/WMO Headers MIAHSFAT2/FZNT02 KNHC for more
details.

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

The Monsoon Trough reaches the coastal sections of Liberia near
06N10W to 03N15W. The ITCZ continues from 03N15W to 02N22W, 03N27W
01N35W 01N41W, reaching the equator along 45W. Convective
precipitation: scattered moderate to isolated strong from 01N to
02N between 06W and 07W. Widely scattered moderate to isolated
strong from 04N southward between 36W and 40W. Isolated moderate
elsewhere from 10N southward from 60W eastward.

High level moisture is being pushed northeastward by the upper
level SW wind flow in the Atlantic Ocean. The high level moisture
is to the south of the line 28N15W 27N30W 23N40W 14N50W 13N60W.

...DISCUSSION...

...THE GULF OF MEXICO...

An upper level ridge is along 104W in Mexico. Upper level NW wind
flow spans the Gulf of Mexico. Comparatively drier air in
subsidence is apparent in water vapor imagery from 26N southward.
A separate upper level anticyclonic circulation center is in the
SW corner of the area near 22N94W.

A surface trough is along 93W/94W from 23N southward.

Rainshowers are possible from 27N southward, in random scattered/
broken low level clouds.

A 1021 mb high pressure center is near 29N84W. Surface
anticyclonic wind flow covers the Gulf of Mexico from 24N
northward.

...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: none.

IFR: none.

MVFR: KVAF, KEIR, and KVOA.

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

TEXAS: MVFR in Brownsville. LIFR, from Alice to Corpus Christi and
Rockport and Port Lavaca, in Galveston, Pearland, and to Beaumont/
Port Arthur. IFR in Victoria. MVFR in Palacios. LOUISIANA: LIFR
from Lafayette to the west and southwest, and in Patterson. MVFR
in New Iberia. MVFR in Galliano and Baton Rouge. IFR around the
southern part of Lake Pontchartrain. LIFR on the NE part of the
Lake. MVFR on the NW part of the Lake. MISSISSIPPI: LIFR in the
coastal plains/southernmost sections, except for MVFR at the
Stennis International Airport. MVFR in Natchez. IFR in McComb.
MVFR in parts of the Hattiesburg metropolitan area. ALABAMA:
LIFR in parts of the Mobile metropolitan area. MVFR in Gulf
Shores. IFR in Evergreen. IFR during the last hour in Dothan. FLORIDA:
LIFR in Milton and Crestview. MVFR in Destin. LIFR in the NW part
of the Panama City metropolitan area, Apalachicola, Tallahassee,
and Perry, Cross City, and Brooksville. IFR and mist at the St.
Pete/Clearwater International Airport.

...THE CARIBBEAN SEA...

Upper level NW wind flow is sweeping across the area, from Cuba
to the Greater Antilles and eastward. Upper level NE wind flow is
moving into the NW corner of the Caribbean Sea.

Upper level SW wind flow is from 17N southward from 83W eastward.

Comparatively drier air in subsidence is apparent in water vapor
imagery, nearly everywhere, except in the area that is from 17N
southward between 64W and 78W.

Scattered to broken low level clouds and possible rainshowers are
to the south of 14N72W 16N66W 14N63W 12N63W 12N60W.

The monsoon trough is along 08N/09N between 76W and beyond 83W/84W
in Costa Rica. No significant deep convective precipitation is
apparent.

24-HOUR rainfall totals in inches for the period ending at
29/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.01 in
Guadeloupe.

...HISPANIOLA...

Upper level NW wind flow is moving across Hispaniola, with an
Atlantic Ocean-to-Caribbean Sea trough. Comparatively drier air
in subsidence is apparent in water vapor imagery, across the
entire area.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti:
VFR/no ceiling. for the DOMINICAN REPUBLIC: Barahona: VFR/ no
ceiling. few cumulonimbus clouds. 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 ridge will be in
the Caribbean Sea, combined with an Atlantic Ocean trough. The
GFS MODEL forecast for 500 MB shows that N-to-NE wind flow will
move across the area during the next the first 18 hours to 24
hours. A trough will be across the Mona Passage at the start of
the forecast period. A ridge will settle in, across Hispaniola,
with time, during day one. Expect anticyclonic wind flow with the
ridge during day two. The GFS MODEL forecast for 700 mb shows
that NE wind flow will move across the area during the first 12
hours to 18 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 upper level trough is along 63W/65W from 23N northward. A
surface trough is along 31N64W 26N68W. Convective precipitation:
isolated moderate from 24N northward between 58W and 66W. A cold
front passes through 32N70W to 32N73W. A stationary front
continues from 32N73W beyond SE Georgia. Convective precipitation:
broken to overcast multilayered clouds and possible rainshowers
are from 28N northward from 64W westward. A surface trough is
along 25N70W 20N71W. Convective precipitation: rainshowers are
possible also from 20N to 25N between 64W and 73W, in areas of
scattered/broken low level clouds.

An upper level trough extends from a 35N31W cyclonic circulation
center to 28N38W, to an 18N46W cyclonic circulation center, to
14N48W and 14N57W. The upper level trough supports a cold front
that passes through 32N24W to 28N25W and 24N30W. A stationary
front continues from 24N30W 21N36W and 20N41W. A dissipating
stationary front continues from 20N41W to 20N53W. Convective
precipitation: Rainshowers are possible from 17N northward between
23W and 60W.

Surface anticyclonic wind flow covers the Atlantic Ocean from 22N
northward between 37W and 60W, to the W and NW of the cold front.
A 1028 mb high pressure center is near 31N49W. A 1022 mb high
pressure center is near 27N75W. Surface anticyclonic wind flow
covers the Atlantic Ocean from 24N to 31N between 70W and 80W.

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

$$
MT
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