[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301205
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
705 AM EST FRI DEC 30 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
1115 UTC.

...SPECIAL FEATURES...

...Gulf of Mexico Gale Warning...

A cold front passes through 26N82W to 21N98W. Expect NW-to-N
gale- force winds, and sea heights ranging from 8 feet to 12 feet,
to the south of 24N to the west of the cold front, for the next 12
hours or so. Please read the High Seas Forecast under AWIPS/WMO
Headers MIAHSFAT2/FZNT02 KNHC, and the OFFSHORE FORECAST...
MIAOFFNT4/FZNT24 KNHC, for more details.

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

The Monsoon Trough is along 01N/02N from 09W eastward. The ITCZ
continues from 02N/03N to 45W. Convective precipitation:
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
covers the area that is from 15N to 29N between Africa and 30W,
and within 150 nm to 210 nm on either side of the line 17N30W
12N40W 05N52W.

...DISCUSSION...

...THE GULF OF MEXICO...

An upper level trough is supporting the current cold front that is
sweeping across the area. The trough is moving through the Great
Lakes area and the eastern half of the U.S.A. The cyclonic wind
flow that is moving around the trough reaches as far to the south
as southern South Carolina and central Georgia. Upper level NW-
to-W wind flow spans the Gulf of Mexico. High level clouds cover
the area that is from 23N northward. The clouds are overtaking the
earlier comparatively drier air in subsidence that has been
apparent in water vapor imagery during the last few days. The
drier air now is from 24N southward. Rainshowers are possible
along and to the northwest of the cold front. The cold front
passes through Lake Okeechobee in south Florida, to 24N90W, to the
coast of Mexico near 21N97W.

A separate area of upper level SE wind flow is moving through the
SW corner of the Gulf of Mexico, from 20N southward.

Gale-force winds are blowing in the Gulf of Tehuantepec on the
eastern Pacific Ocean side of southern Mexico. Please read the
Eastern Pacific Ocean HIGH SEAS FORECAST...MIAHSFEP2/FZPN03
KNHC...and the Eastern Pacific Ocean TROPICAL WEATHER
DISCUSSION...MIATWDEP/AXPZ20 KNHC...for more details.

...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: KGHB, KGRY, and KIKT.

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

from TEXAS to ALABAMA: VFR. FLORIDA: MVFR and light rain in
Marathon Key. light rain has ended at the Key West International
Airport.

...THE CARIBBEAN SEA...

Middle level NW wind flow moves from Florida and the Bahamas
toward Hispaniola, and then it turns anticyclonically toward the
SW corner of the Caribbean Sea. Comparatively drier air in
subsidence is apparent in water vapor imagery.

Upper level anticyclonic wind flow covers the area that is from
18N southward from 80W eastward.

Scattered to broken low level clouds and possible rainshowers are
within 90 nm on either side of the line that runs from 19N74W
near Haiti, to 16N78W, beyond 12N84W into Nicaragua. Similar
clouds and possible precipitation are from 10N to 14N between 54W
in the Atlantic Ocean and 66W in the Caribbean Sea.

24-HOUR rainfall totals in inches for the period ending at
30/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.03 in
Curacao, and 0.02 in Guadeloupe.

...HISPANIOLA...

Middle level anticyclonic wind flow is moving across Hispaniola,
with an Atlantic Ocean-to-Caribbean Sea ridge. Comparatively drier
air in subsidence is apparent in water vapor imagery, across the
entire area. Convective precipitation: rainshowers are possible
inland, and in the coastal waters, in areas of scattered to broken
low level clouds.

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: IFR and mist. Puerto Plata: VFR/no
ceiling.

The GFS MODEL forecast for 250 MB shows that a Colombia-to-Yucatan
Peninsula ridge will bring NW wind flow across the area during
the next 48 hours. The GFS MODEL forecast for 500 MB shows that
an E-to-W oriented ridge will bring anticyclonic wind flow across
the area during the next 48 hours. The GFS MODEL forecast for 700
mb shows that first easterly wind flow, will be followed by
large-scale anticyclonic wind flow, and then followed by more
easterly wind flow, during the next 48 hours. Everything will have
to do with an Atlantic Ocean ridge.

...THE ATLANTIC OCEAN...

The upper level trough that is supporting the current Atlantic
Ocean-to-Gulf of Mexico cold front is pushing scattered-to-broken
multilayered clouds and possible rainshowers into the Atlantic
Ocean, from 25N northward from 60W westward. Convective
precipitation: Isolated moderate within 60 nm on either side of
32N68W 29N73W 27N77W. A surface trough remains across the east of
the SE Bahamas and just to the north of Hispaniola, along 71W/72W
from 20N to 24N. Rainshowers are possible from 20N to 26N between
68W and 75W.

An upper level trough extends from a 34N29W cyclonic circulation
center to 29N25W, 21N39W, and 13N53W. A 1012 mb low pressure
center is near 32N28W. Convective precipitation: Isolated
moderate from 30N to 32N between 20W and 26W. Rainshowers are
possible elsewhere from 15N northward between 20W and 60W.

Surface anticyclonic wind flow covers the Atlantic Ocean from 18N
northward between 33W and 60W. A 1024 mb high pressure center is
near 30N49W.

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

$$
MT
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