129
AXNT20 KNHC 151202
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
634 AM EDT Sun Oct 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 0600 UTC surface analysis and satellite imagery through
1015 UTC.

...SPECIAL FEATURES...

Hurricane Ophelia is centered near 39.0N 18.3W at 15/0900 UTC or
about 412 nm E of the Azores, moving NE at 30 kt. Estimated
minimum central pressure is 964 mb. Maximum sustained winds are
90 kt with gusts to 110 kt. Scattered moderate convection is
from 37N-42N between 16W-20W. Some additional weakening is
expected today and on Monday, but Ophelia is forecast to become
a powerful post-tropical cyclone with hurricane-force winds as
it approaches Ireland on Monday. See the latest
Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC
for more details.

A cold front will move off the coast of Texas tonight, reach
from the Florida Big Bend to 23N94W to the Bay of Campeche late
Mon, and then stall from Tampa Bay to 25N91W to 18N93W late Tue
night. Meanwhile a trough over the south central Gulf, on the
northern extent of a tropical wave, will drift into the SW Gulf
ahead of the front through Mon. The combination of a slightly
tighter pressure gradient along with cooler and drier air
associated with the front will allow winds funneling along the
coast of Mexico to reach minimal gale force from Tampico to
Veracruz Monday through late Tuesday, with seas reaching 8 to 13
ft.

...TROPICAL WAVES...

A tropical wave is over the central Atlantic with axis extending
from 14N39W to 03N40W, moving W at 20 kt. The wave is in an area
of moderate moisture as noted on SSMI TPW imagery. The wave is
in a distinct surface trough, and a weak 700 mb trough.
Scattered moderate convection is from 06N-10N between 39W-42W.
Scattered showers are elsewhere within 120 nm of the wave axis.

A tropical wave is over the central Atlantic with axis extending
from 16N46W to 05N48W, moving W at 10 kt. The wave is in an area
of moderate moisture as noted on SSMI TPW imagery. The wave is
in a distinct surface trough, and a weak 700 mb trough.
Scattered moderate convection is from 11N-15N between 44W-52W.

A tropical wave is over the E Caribbean with axis extending from
23N64W to an embedded 1009 mb low near 20N65W to 13N66W, moving
W at 15 kt. The wave is in an area of abundant moisture as noted
on SSMI TPW imagery. The wave is in a distinct surface trough,
and a distinct 700 mb trough. Scattered moderate convection is
from 17N-23N between 59W-65W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 10N14W to
09N19W. The Intertropical Convergence Zone axis extends from
09N19W to 06N30W to 05N39W. The ITCZ then resumes near 05N42W to
07N47W...resuming again near 08N50W to 09N61W. Aside from the
convection associated with the tropical waves, scattered
moderate/isolated strong convection is from 04N-08N between 18W-
26W, and from 09N-11N between 57W-59W.

...DISCUSSION...

GULF OF MEXICO...

A surface trough is over the W Gulf of Mexico from 26N93W to
23N92W to 18N92W. Scattered showers are within 120 nm of the
trough. Mostly fair weather is over the remainder of the Gulf.
10-20 kt surface winds are over the Gulf, with strongest winds
over the NE Gulf. In the upper levels, an upper level high is
centered over the Yucatan Peninsula near 20N90W, with subsidence.
Expect the surface trough to move W over the next 24 hours. Also
expect a cold front to move off the coast of Texas early Monday
morning with fresh to strong winds behind it. Gale force winds
will develop associated with this front. See special features
above.

CARIBBEAN SEA...

A tropical wave is over the E Caribbean. See above. The eastern
extent of the E Pacific monsoon trough is over Costa Rica and
Panama. Isolated moderate convection is over the SW Caribbean
from 10N-14N between 80W-84W. Scattered showers are over
Honduras and Nicaragua. Of note in the upper levels, a small
upper level high is centered over the Windward Islands near
14N65W, with subsidence. Expect the E Caribbean tropical wave to
produce additional convection over the next 24 hours.

...HISPANIOLA...

Presently scattered moderate convection persists over SW Haiti.
Expect scattered showers and convection to build in the afternoon
and evening hours, mostly due to the tropical wave.

ATLANTIC OCEAN...

Hurricane Ophelia is over the E Atlantic. See above. A surface
trough is over the W Atlantic and the Bahamas from 30N78W to an
embedded 1015 mb low near 27N80W to 24N80W. Scattered showers are
within 60 nm of the trough. The system is moving W towards
Florida. Further east, a surface trough is noted from 30N63W to
23N67W. Scattered moderate convection is within 90 nm of the
trough. Elsewhere, scattered moderate convection is over the E
Atlantic from 29N-31N between 37W-42W due to a dissipated cold
front.

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

$$
Formosa