[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 150604
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
104 AM EST Wed Feb 15 2017

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...

...GALE WARNING FOR THE GULF OF MEXICO...

The 15-hour forecast consists of: a cold front from 30N86W to
23N90W to 18.5N95W. Expect NW gale-force winds and sea heights
building to 8 feet, to the south of 21N to the west of 95W.
Please read the latest NWS High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 KNHC for more details.

...GALE WARNING FOR THE ATLANTIC OCEAN...

The 18-hour forecast consists of a cold front that will be
approaching the area from the west. Expect SW gale-force winds and
sea heights ranging from 9 feet to 12 feet, to the north of 30N
between 76W and 80W. Please read the latest NWS High Seas Forecast
under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough reaches the coastal sections of Sierra Leone
near 08N13W, to 01N19W. The ITCZ continues from 01N19W, crossing
the equator along 20W, to 03S26W, crossing the equator along 32W,
to 03N42W, to 02N50W. Convective precipitation: Widely scattered
moderate to isolated strong from 07N southward from 50W eastward.
A surface trough is along 06N37W 03N40W, based on scatterometer
data.

...DISCUSSION...

...THE GULF OF MEXICO...

A middle level-to-upper level trough extends from an Arkansas
cyclonic circulation center, to the Lower Texas Gulf coast, along
the coast of Mexico, into the SW corner of the Gulf of Mexico.
This feature is supporting a cold front that passes through SW
Louisiana, into the west central Gulf of Mexico, to the Mexico
coast near 22N98W, and then curving inland to 25N101W. Convective
precipitation: widely scattered moderate to isolated strong within
30 nm to 60 nm on either side of the line from 26N92W to 28N90W to
the Florida Panhandle.

Upper level anticyclonic wind flow spans the rest of the area that
is to the east of the trough.

...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: KGRY and KMDJ.

IFR: none.

MVFR: KBQX, KXIH, KHHV, KVAF, KEMK, KGUL, KHQI, KEHC, KVQT, KGHB,
KEIR, KSPR, 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...

TEXAS: MVFR from Bay City to Huntsville and to Jasper. LOUISIANA:
MVFR/IFR from Hammond/Baton Rouge southward. light rain in Baton
Rouge, and a bit on the southern side of Lake Pontchartrain.
MISSISSIPPI: MVFR from Natchez to McComb to Hattiesburg; light
rain in McComb and in Biloxi. ALABAMA: MVFR in Evergreen. rain in
Gulf Shores. FLORIDA: light rain in Pensacola. IFR/MVFR from
Pensacola to Milton and Crestview. LIFR/IFR from Perry to
Brooksville, and to parts of the Tampa/St.Petersburg metropolitan
area. LIFR/IFR from Punta Gorda to Naples.

...THE CARIBBEAN SEA...

Upper level anticyclonic wind flow covers the NW corner of the
Caribbean Sea. This anticyclonic wind flow is related to the upper
level ridge that is in the Gulf of Mexico, and to the east of the
trough that is supporting the current cold front.

Upper level anticyclonic wind flow is from 15N southward from 75W
eastward.

Middle level-to-upper level cyclonic wind flow covers the area
from 15N northward from 70W eastward. This wind flow is part of
the larger-scale central Atlantic Ocean trough, that is driving
the 32N46W-to-28N80W frontal boundary.

Comparatively drier air in subsidence is apparent in water vapor
imagery across the area.

Rainshowers are possible to the north of the line that extends
from 17N60W to 16N70W to 13N83W at the coast of Nicaragua.

24-HOUR rainfall amounts, for the period ending at 15/0000 UTC...
according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION
TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.01 in Guadeloupe.

...HISPANIOLA...

Middle level to upper level NW wind flow is present across the
area. Southerly wind flow is from 600 mh to 800 mb. Comparatively
drier air in subsidence is apparent in water vapor imagery across
Hispaniola. Convective precipitation: rainshowers are possible
inland, and in the waters that surround Hispaniola.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti at 15/0200 UTC:
MVFR. ceiling 3000 feet. for the DOMINICAN REPUBLIC: Barahona: VFR
at 15/0000 UTC. Santo Domingo: MVFR. ceiling 1600 feet. La
Romana/Punta Cana: VFR. Santiago/Puerto Plata: VFR.

The GFS MODEL forecast for 250 MB shows that the 48-hour forecast
period will start with NW wind flow. The wind flow will be from
the SW for the rest of the forecast period, with a ridge.
The GFS MODEL forecast for 500 MB shows that day one will start
with an anticyclonic circulation center about 100 nm to the
southwest of the SW coast of Haiti. The anticyclonic circulation
center is forecast to move across the eastern extreme of
Hispaniola, and then to Puerto Rico, and then about 60 nm to the
SSE of Puerto Rico, and finally to a position that is about 90 nm
to the west of Guadeloupe at the end of day one. The wind flow
will start as anticyclonic, followed by SW for the rest of day
one. Expect NW wind flow across Hispaniola during day two, as
Hispaniola is forecast to be on the northerly side of a Caribbean
Sea ridge. The GFS MODEL forecast for 700 mb shows that broad
anticyclonic wind flow will cover Hispaniola during the next 48
hours. At least one anticyclonic circulation center will be on top
of Hispaniola or close enough to Hispaniola, in order to create
the nearly constant anticyclonic wind flow across the island.

...THE ATLANTIC OCEAN...

A central Atlantic Ocean deep-layer trough is supporting a cold
front that passes through 32N46W to 29N50W to 26N62W. The front
is stationary from 26N62W to 25N70W. The front is dissipating
stationary from 25N70W to 28N80W. Convective precipitation:
rainshowers are possible from 24N northward between 40W and the SE
U.S.A. A 1017 mb high pressure center is near 30N71W. Surface
anticyclonic wind flow is to the northwest of the frontal
boundary.

The upper level trough that was about 450 nm to the east of
Africa about 24 hours ago, now has moved inland in Africa. Upper
level NW wind flow, on the western side of the trough, covers the
Atlantic Ocean from 17N northward from 30W eastward. A cold front
lags behind the upper level trough, passing through 32N20W to
30N20W to 27N25W. Convective precipitation: isolated moderate to
locally strong from 29N northward between Africa and 20W.
Rainshowers are possible also from 22N northward between 20W and
40W.

A surface trough is along 29N40W 24N50W 20N56W 19N64W. Convective
precipitation: widely scattered moderate from 24N to 27N between
44W and 48W. Rainshowers are possible elsewhere from 18N to 26N
between 50W and 65W.

A 1021 mb high pressure center is near 23N37W. Surface
anticyclonic wind flow covers the Atlantic Ocean from 10N to 27N
between 25W and 45W.

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

$$
MT
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