Tropical Weather Discussion
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000
AXNT20 KNHC 170605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 AM EDT Sat Jun 17 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 FEATURE...

A tropical wave is along 35W/36W from 11N southward. The wave is
moving westward 10 to 15 knots. A 1012 mb low pressure is along
the tropical wave near 05N. The precipitation has become better
organized during the last 24 hours or so. The chance of formation
into a tropical cyclone during the next two days is medium. Widely
scattered moderate to isolated strong from 03N to 06N between 38W
and 41W. Isolated moderate from 06N to 08N between 35W and 38W.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 22W/23W from 11N
southward, moving westward 10 to 15 knots. Scattered to numerous
strong from 04N to 06N between 26W and 29W. Isolated moderate to
locally strong elsewhere from 10N southward between 20W and 33W.

An Atlantic Ocean tropical wave is along 42W/43W from 15N
southward moving westward 10 knots. A 1013 mb low pressure center
is along the wave near 08N. Scattered moderate to strong
rainshowers are from 09N to 11N between 44W and 48W.

A Caribbean Sea tropical wave is along 75W/76W, from 19N
southward, between Haiti and Jamaica. Scattered to numerous strong
rainshowers are from 15N to SE Cuba and the Windward Passage
between 73W and 78W. Numerous strong is in Colombia and Venezuela
from 07N to 10N between 72W and 74W, and in the Gulf of Uraba of
Colombia. The precipitation that covers the area from 15N
northward is part of a larger-scale area of rainshowers with
thunder that is going to remain in the NW corner of the Caribbean
Sea, with a large-scale area of broad surface low pressure.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough passes through the coastal sections of Senegal
near 15N17W, to 07N24W, 07N30W 05N36W, and 07N41W. The ITCZ is
along 07N45W 06N51W 07N54W, into Guyana near 06N58W. Convective
precipitation: scattered to numerous strong from 08N to 11N
between 13W and 16W. Widely scattered moderate to isolated strong
from 04N to 08N between 10W and 20W. Isolated moderate to
locally strong elsewhere from 10N southward from 60W eastward.

...DISCUSSION...

...THE GULF OF MEXICO...

An upper level trough is along 84W in the Gulf of Mexico. Upper
level cyclonic wind flow covers much of the Gulf of Mexico. Upper
level anticyclonic wind flow covers the area from 95W westward.
Comparatively drier air in subsidence is apparent in water vapor
imagery.

A 1014 mb high pressure center is near 26N86W. Surface
anticyclonic wind flow is moving around the 1014 mb high pressure
center, that is near 26N86W, from 90W eastward.

...CURRENT CONDITIONS AND WEATHER, FOR THE OFFSHORE OIL
PLATFORM SITES, FROM 27N NORTHWARD AND FROM 88W WESTWARD...

LIFR: none.

IFR: none.

MVFR: KMIS.

CURRENT CONDITIONS AND WEATHER, FOR THE COASTAL PLAINS OF THE
U.S.A., FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

Texas: MVFR in parts of the interior sections of the Lower Valley.
MVFR in Rockport. LOUISIANA: MVFR in parts of the SW corner of the
state. Rainshowers and thunder along the northern side of Lake
Pontchartrain. MISSISSIPPI: current rain, or rain that ended
during the last hour or so, in the southernmost sections of the
state. ALABAMA: current rain, or rain that ended during the last
hour or so, from Evergreen southwestward. FLORIDA: MVFR in Milton.

...THE CARIBBEAN SEA...

Scattered to numerous strong rainshowers are from 15N to SE Cuba
and the Windward Passage between 73W and 78W, from NE Costa Rica
into SE Nicaragua, and along the eastern coast of Honduras. A
surface trough is along 83W/84W from 15N to 19N, off the coast of
Honduras. Upper level anticyclonic wind flow covers the Caribbean
Sea from 70W westward. A broad area of low pressure is expected
to form in this area during the next day or two. Scatterometer
data have been showing moderate-to-fresh winds in the wake of a
tropical wave that already has moved inland in Central America.
Mainly gentle to moderate winds are in the NW Caribbean Sea.
Wind speeds are expected to increase, and sea heights will build,
across the central and western Caribbean Sea, during the upcoming
weekend. A tight pressure gradient will exist between the
developing low pressure area and the Atlantic Ocean ridge. Plenty
of moisture and very active weather also are expected with this
low pressure center. It is likely that this weather will be affecting
the western and central Caribbean Sea, Central America, and most
of Cuba during the weekend. It is possible that locally heavy
rain and gusty winds may occur in parts of Cuba, the Yucatan
Peninsula and Central America.

24-hour rainfall totals that are listed for the period that ended
at 17/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.01 in
Tegucigalpa in Honduras.

...HISPANIOLA...

Upper level NW wind flow is moving across Hispaniola.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: MVFR for the
visibility. for the DOMINICAN REPUBLIC: Barahona: VFR. few
cumulonimbus clouds. Santo Domingo: MVFR. ceiling 1600 feet.
La Romana: VFR. few cumulonimbus clouds. Punta Cana: VFR.
Santiago: VFR. Puerto Plata: VFR. few cumulonimbus clouds.

The GFS MODEL forecast for 250 mb shows that NW wind flow will
move across the area during the next 48 hours. N wind flow is
possible, also, at the end of the 48-hour forecast period. A
Nicaragua-to-Cuba ridge will be to the west of Hispaniola. The
GFS MODEL forecast for 500 mb shows that anticyclonic wind flow
will span the entire area, either with an anticyclonic circulation
center, or with a ridge, during the first 24 to 30 hours. Expect
cyclonic wind flow with an inverted trough for the rest of the
time period. The GFS MODEL forecast for 700 mb shows that SE wind
flow will move across the area during the next 48 hours, with
Hispaniola being on the southern side of an Atlantic Ocean-to-
northern Caribbean Sea ridge.

...THE ATLANTIC OCEAN...

An upper level trough passes through 32N43W, to 31N51W, to a
25N55W cyclonic circulation center, to 16N59W and to northern
Venezuela near 10N63W. A stationary front is along 32N/33N between
55W and Bermuda. A surface trough is along 31N57W 28N59W 26N61W.
Isolated moderate rainshowers cover the Atlantic Ocean from 10N
northward between 50W and 70W.

An upper level trough extends from a 32N17W cyclonic circulation
center, to a 26N25W and 20N32W. No significant deep convective
precipitation is apparent in satellite imagery.

A surface ridge extends from a 1028 mb high pressure center that
is near 34N30W, through 32N34W, to 27N42W, 22N52W, and 18N59W.

A 1019 mb high pressure center is near 28N67W. Surface
anticyclonic wind flow covers the area from 20N northward between
63W and 80W.

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

$$
MT



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