[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 300604
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
104 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
0515 UTC.

...SPECIAL FEATURES...

...Gulf of Mexico Gale Warning...

A cold front passes through 30N80W, to 26N90W, 25N95W 22N98W,
curving to 23N100W inland. A stationary front continues from
23N100W to 29N105W. A dissipating stationary front continues from
29N105W into SW New Mexico near 32N108W. Expect gale-force winds
to develop soon, to the south of 24N to the west of the cold front.
Expect sea heights to range from 10 feet to 14 feet. 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 passes through the Prime Meridian along 05N to
04N10W and 03N15W. The ITCZ continues from 03N15W to 02N30W
01N40W, crossing the equator along 44W, and to 01S46W. Convective
precipitation: scattered moderate to strong from 01N to 02N
between 41W and 45W. isolated moderate elsewhere from 05N
southward from 50W eastward, and elsewhere from 10N southward
between 50W and 60W.

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
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 23N southward. Rainshowers are possible along and to
the northwest of the cold front. The cold front passes through
30N80W, to 26N90W, 25N95W 22N98W, curving to 23N100W inland. A
stationary front continues from 23N100W to 29N105W. A dissipating
stationary front continues from 29N105W into SW New Mexico near
32N108W.

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: KHHV 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 in Brooksville.
MVFR and rain in Punta Gorda. MVFR in Naples.

...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 19N75W near
Haiti, to 15N79W, beyond 12N83W into Nicaragua. Similar clouds and
possible precipitation are from 10N to 14N between 54W in the
Atlantic Ocean and 65W in the Caribbean Sea.

The monsoon trough passes through western sections of Panama,
across the southern half of Costa Rica, and then into the eastern
Pacific Ocean. No significant deep convective precipitation is
apparent, other than for the possible rainshowers with the low
clouds that are moving southwestward from 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. few cumulonimbus clouds were being reported in the
last several observations. Santiago: VFR. few cumulonimbus clouds.
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 26N northward from 60W westward. A surface trough is
along 32N74W to the NW Bahamas near 26N78W. A second surface
trough remains just to the east of the SE Bahamas and just to the
north of Hispaniola. Rainshowers are possible from 20N to 26N
between 67W and 73W.

An upper level trough extends from a 34N29W cyclonic circulation
center to 29N25W, 21N39W, and 13N53W. A 1012 mb low pressure
center is near 32N29W. A surface trough passes through 32N22W to
24N27W. Convective precipitation: Isolated moderate from 30N to
32N between 21W and 28W. Rainshowers are possible elsewhere from
15N northward between 20W and 60W.

Surface anticyclonic wind flow covers the Atlantic Ocean from 18N
northward between 35W and 62W. A 1025 mb high pressure center is
near 30N48W.

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

$$
MT
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