Tropical Weather Discussion
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000
AXNT20 KNHC 140606
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
106 AM EST Tue Nov 14 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...
A 1010 mb low pressure center is near 32N31W, about 390 nm to the
SSW of the Azores. A surface trough extends from the low center to
30N31W 27N33W 24N36W. Rainshowers are possible from 25N northward
between 30W and 40W. The low center is supported aloft by a
middle level to upper level cyclonic circulation center, that is
near 33N31W. Precipitation: widely scattered to scattered
moderate and isolated strong rainshowers from 30N to 36N between
26W and 32W. This low pressure center has a medium chance of
becoming a subtropical cyclone during the next couple of days as
it moves to the NE, before upper-level winds become unfavorable.
Expect near gale-force winds during the next day or two.

...ITCZ/MONSOON TROUGH...
The monsoon trough passes through coastal sections of Sierra Leone
near 08N13W to 07N17W. The ITCZ continues from 07N17W to 08N24W,
04N35W, 04N49W, and into Brazil, and French Guiana near 03N53W.
Precipitation: scattered strong from 04N to 06N between 09W and
12W. scattered moderate to isolated strong from 04N to 09N between
14W and 20W. isolated moderate elsewhere from 13N southward from
60W eastward. Upper level SW wind flow covers the Atlantic Ocean
to the S and SE of the line from 26N15W to 23N30W to 13N45W to
07N56W. Broken to overcast multilayered clouds and possible
rainshowers are in this same area.

...DISCUSSION...

THE GULF OF MEXICO...
An upper level trough passes through central Florida into the SE
corner of the area. The trough supports a cold front, that passes
through 32N77W to the Florida coast near 30N81W, to 29N85W in the
Gulf of Mexico. Upper level SW wind flow is moving from the
Yucatan Channel, toward south Florida and beyond the Bahamas. The
upper level SW wind flow is part of a larger-scale area of
anticyclonic wind flow that is extending from the Caribbean Sea,
across the Greater Antilles, into the Atlantic Ocean.
Precipitation: isolated moderate from 23N to 24N between 87W and
89W. rainshowers are possible in parts of the Straits of Florida,
south Florida, and toward the Bahamas.

A surface ridge passes through NE Texas, through the deep south
of Texas, to Mexico near 24N99W, into the Isthmus of Tehuantepec
of southern Mexico.

The current pressure gradient is expected to relax somewhat by
Wednesday. The wind speeds will be decreasing, into gentle-to-
moderate breezes, and gentle southerly return flow re-
establishing itself across the NW waters.

THE CARIBBEAN SEA...
Large-scale upper level anticyclonic wind flow spans the area.
A ridge extends from the SW corner of the area, beyond 30N69W in
the Atlantic Ocean.

A surface trough extends from a 1005 mb low pressure center that
is near 11N78W, to 15N81W, to 20N81W, near the Cayman Islands.
Precipitation: widely scattered to isolated strong rainshowers
from 73W westward, including in the Windward Passage, along the
coast of Colombia.

A second surface trough extends from Cuba near 21N77W, across the
central Bahamas, to 26N74W in the Atlantic Ocean. Precipitation:
widely scattered moderate to isolated strong from 20N northward
from 63W westward. Upper level anticyclonic wind flow is moving on
top of this area, with the upper level ridge that runs from the SW
corner of the Caribbean Sea to 30N69W in the Atlantic Ocean.

Moderate to fresh tradewinds prevail, and they are expected to
persist through Tuesday. Global models indicate a broad and
stretched out area of surface low pressure developing from the
waters NE of Cuba to Jamaica and into the SW Caribbean Tuesday
night into Wednesday quickly moving E-NE and merging with a
frontal boundary in the SW North Atlc Wednesday night into
Thursday.

...HISPANIOLA...
Widely scattered moderate to isolated strong rainshowers are in
the Windward Passage. Surface observations are not reporting
rainshowers. Cumulonimbus clouds are being reported in Port-au-
Prince in Haiti. Upper-level W wind flow is moving across the
area. Low-level moisture convergence continues to be maximized
across the region within E-SE tradewinds. This overall pattern
will persist through Thursday with precipitation expected to
increase during the next 24 to 48 hours.

THE ATLANTIC OCEAN...
A surface trough is along 23N25W 20N27W 16N28W. Upper level
 SW wind flow covers the Atlantic Ocean
to the S and SE of the line from 26N15W to 23N30W to 13N45W to
07N56W. Broken to overcast multilayered clouds and possible
rainshowers are in this same area.
ar 32N32W.

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

$$
MT



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