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045
AXNT20 KNHC 271112
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 AM EDT TUE SEP 27 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 0600 UTC surface analysis and satellite imagery through
1045 UTC.

...SPECIAL FEATURES...

An Atlantic Ocean tropical wave is along 51W from 17N southward.
A 1008 mb low pressure center is along the wave near 11N.
Convective precipitation: widely scattered moderate to isolated
strong from 11N to 17N between 48W and 55W. The precipitation
pattern continues to become more organized. It is likely that a
tropical depression or a tropical storm may form later today if
this weather system continues to become more organized. The
forecast movement is to the WNW-to-W about 20 mph. Please
monitor the progress of this weather system if you have any
interests that are in the eastern and central Caribbean Sea,
including the northern coast of South America. Heavy rains and
strong gusty winds, possibly to tropical storm force, are
expected to spread across the Windward Islands and sections of
the southern Lesser Antilles beginning tonight and continuing
into Wednesday. An Air Force Reserve reconnaissance aircraft is
scheduled to investigate the disturbance this afternoon.
The chance of formation during the next 48 hours is high. Gale
wind conditions are forecast in 24 hours, within 120 NM N
semicircle of a 1006 mb low pressure center near 13N57W, and sea
heights are forecast to range from 10 feet to 13 feet. Please
refer to the HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC for more
details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 21W/22W from 16N
southward, moving westward 10 to 15 knots. Convective
precipitation: Monsoon trough precipitation, isolated moderate
to locally strong, is from 10N southward between 10W and 30W.

A Caribbean Sea tropical wave is to the south of 19N, passing
through the Mona Passage to 14N69W, and to 09N69W in NW
Venezuela. Convective precipitation: isolated moderate from 10N
to 20N between 60W and 70W. An upper level trough extends from
an Atlantic Ocean 25N69W cyclonic circulation center, to Puerto
Rico, into the Caribbean Sea, and toward Lake Maracaibo in NW
Venezuela. Convective precipitation: isolated moderate from 20N
southward between 60W and 70W. It is not easy to figure out
which precipitation just is related to the tropical wave, and
which precipitation is related only to the upper level trough.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through coastal sections of Guinea
near 10N14W, to 08N20W, to 08N35W and 11N48W. Convective
precipitation: scattered strong from 05N to 07N between 28W and
34W, and from 10N to 12N between 34W and 38W. Isolated moderate
elsewhere from 13N southward from 48W eastward.

...DISCUSSION...

...THE GULF OF MEXICO...

An upper level cyclonic circulation center is inland near
Lakeland in Florida. Upper level cyclonic wind flow covers much
of the Gulf of Mexico that is from 90W westward. A 1013 mb low
pressure center is just off the coast of NE Florida. A surface
trough extends northeastward to 32N80W. A second part of the
surface trough extends from the low pressure center to SW
Florida. Convective precipitation: isolated moderate from 20N in
the NW corner of the Caribbean Sea northward, between the NW
Bahamas and 84W. in the Atlantic Ocean: widely scattered
moderate to isolated strong from Cuba to 32N between 70W and the
NW Bahamas.

Upper level anticyclonic wind flow covers the rest of the Gulf
of Mexico. An upper level ridge cuts through Texas along a NW-to-
SE line, and then across the western sections of the Gulf of
Mexico. A surface trough is along 94W/95W from 27N southward.
Convective precipitation: scattered moderate to strong within 90
nm of the coast of Mexico between 94W and 98W, and within a 30
nm radius of 22N93W.

...FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE IN THE AREA
WHOSE BOUNDARIES ARE FROM 27N NORTHWARD AND FROM 88W WESTWARD...

LIFR: none.

IFR: KGLS and KVAF.

MVFR: KMZG.

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

TEXAS: light rain in Harlingen. IFR in Weslaco and Edinburg.
MVFR in McAllen and Falfurrias. IFR in Hebbronville. A mixture
of IFR and MVFR observations are being reported from Corpus
Christi eastward to the coast to Rockport. MVFR in Victoria and
Palacios, in Bay City, and Angleton/Lake Jackson. MVFR in Sugar
Land, and in parts of the greater Houston metropolitan area.
LOUISIANA: VFR/no ceilings. MISSISSIPPI: MVFR in Pascagoula.
ALABAMA: LIFR in Evergreen and Troy. FLORIDA: LIFR in Crestview
and in Perry. MVFR in Cross City. rain and thunder in Punta
Gorda.

...THE CARIBBEAN SEA...

Upper level NW wind flow is moving through the Yucatan Channel
into the NW Caribbean Sea. This NW wind flow moves toward the SW
corner of the Caribbean Sea, and toward the coast of Colombia.
A tropical wave is moving through the Mona Passage. Upper level
cyclonic wind flow is moving around a trough that passes through
the Mona Passage, and into the eastern part of the Caribbean Sea.

24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT
27/0000 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...1.15 in Bermuda,
and 0.63 in Guadeloupe, and 0.04 in Tegucigalpa in Honduras.

...HISPANIOLA...

Upper level cyclonic wind flow is moving around a trough that
cuts through the eastern part of the Caribbean Sea. Upper level
N wind flow is moving across Hispaniola. Convective
precipitation: isolated moderate from 17N northward from the
Windward Passage westward.

SURFACE OBSERVATIONS...FOR PORT-AU-PRINCE IN HAITI: as of
27/0200 UTC: MVFR; scattered cumulonimbus clouds. rain and
thunder were reported in observations during the last hour. FOR
THE DOMINICAN REPUBLIC...Barahona: as of 27/0000 UTC; VFR/no
ceilings; few cumulonimbus clouds. Santo Domingo and Punta Cana:
VFR/no ceilings, after earlier observations of rain and thunder.
La Romana: VFR/no ceilings. Santiago: MVFR. Puerto Plata: VFR/no
ceilings.

The GFS MODEL forecast for 250 MB shows that N wind flow will
move across the area during day one. The N wind flow will become
cyclonic as a cyclonic circulation center/trough moves across
Hispaniola during day one. More cyclonic wind flow will be
present during the first half of day two. Expect S wind flow for
the rest of day two. The GFS MODEL forecast for 500 MB and for
700 mb shows that SE wind flow will be moving across the area
for day one, and for the first half of day two. Expect NE and E
wind flow for the second half of day two. A ridge will extend
from the Atlantic Ocean toward the Greater Antilles.

...THE ATLANTIC OCEAN...

Upper level cyclonic wind flow is in the central sections of the
Atlantic Ocean, from 30N northward between 50W and 70W. A cold
front passes through 32N48W to 31N51W. A dissipating stationary
front continues from 31N51W, to 30N56W and 30N65W. Convective
precipitation: isolated moderate to locally strong within 30 nm
on either side of 29N62W 29N55W 29N51W beyond 32N45W. isolated
moderate elsewhere from 20N northward between 50W and 70W.

A surface ridge passes through 32N31W, 27N38W, to 22N58W.

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

$$

MT