[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 140005
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT Fri Oct 13 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 1800 UTC surface analysis and satellite imagery through
2345 UTC.

...SPECIAL FEATURES...

Hurricane Ophelia is centered near 32.3N 31.8W at 13/2100 UTC or
about 415 nm SW of the Azores moving E-NE at 11 kt. Estimated
minimum central pressure is 971 mb. Maximum sustained wind speed
is 85 kt with gusts to 105 kt. Scattered moderate convection is
from 31N-34N between 29W-33W. The center of Ophelia will pass
near or southeast of the southeastern Azores by early Sunday. See
the latest Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22
KNHC for more details.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 14N29W
to 05N26W, moving W at 15 kt. The wave is in a region of strong
vertical shear and IR enhanced imagery show the wave is being
affected by Saharan dry air and dust. These environmental
conditions are limiting convection to scattered moderate from 10N
to 11.5N between 28W-30W.

A tropical wave is E of the Lesser Antilles with axis extending
from 20N56W to 09N60W, moving W at 15 kt. The wave is mainly in a
low to moderate vertical shear environment and CIRA LPW show the
wave is in a region of abundant moisture at the lower levels.
A col at the upper levels support scattered moderate convection
and isolated tstms from 09N-20N between 52W-58W.

A tropical wave is in the Caribbean moving across Central America.
Its axis extends from 17N82W to 07N83W and is moving W at 20 kt. The
wave is mainly in a moderate vertical shear environment and CIRA
LPW show the wave is in a region of abundant moisture at the lower
levels. Middle level diffluence support scattered heavy showers
and tstms S of 17N between 77W-87W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 07N12W to
06N15W. The Intertropical Convergence Zone axis extends from
06N15W to 06N25W, then resumes from 07N28W to 07N51W. Aside from
the convection associated with the tropical waves, scattered
moderate convection is from 10N-13N between 31W-40W. Scattered
moderate to isolated strong convection is from 06N-10N between 44W
and 50W.

...DISCUSSION...

GULF OF MEXICO...

The remnants of a surface trough continue to generate scattered
showers in the SW Gulf. With lack of support aloft, a surface
trough continues to weaken in the SE Gulf where it extends from
26N82W to the NE Yucatan Peninsula near 21N87W. The trough is
supportin isolated showers S of 27N E of 90W. Otherwise, a weak
surface ridge dominates the remainder basin that along with dry
air subsidence from aloft suport fair weather. Winds across the
basin are mainly gentle to moderate from the NNE, except in the SE
Gulf where the surface trough support fresh winds. The surface
trough in the SE Gulf will drifts westward to the south-central
Gulf by early Sunday continuing through Monday when it will
dissipate.

CARIBBEAN SEA...

Upper level diffluence between a trough across the SW N Atlc and
the SW periphery of a ridge in the Caribbean support isolated
showers and tstms across central and eastern Cuba and the passage
between E Cuba and Jamaica. A tropical wave is moving across the
E Gulf of Honduras and Central America, generating scattered heavy
showers and tstms from Honduras to Panama and in the SW Gulf S of
17N. See tropical waves section. Upper level diffluent flow
between an inverted trough in the central Caribbean and a ridge
centered near Puerto Rico along with shallow moisture support
scattered showers and tstms over Hispaniola, SW Puerto Rico and
the Mona Passage. Otherwise, gentle to moderate trades are
expected through Monday, except within 150 nm off the coast of
Colombia where winds will be fresh to strong through Saturday
morning.

...HISPANIOLA...

Upper level diffluent flow between an inverted trough in the
central Caribbean and a ridge centered near Puerto Rico along with
shallow moisture support scattered showers and tstms over
Hispaniola and the Mona Passage. Conditions are forecast to
improve by Saturday morning, however a tropical wave that will
move across Puerto Rico Saturday will increase moisture across the
Island by Sunday, thus increasing the chances for scattered heavy
showers.

ATLANTIC OCEAN...

Hurricane Ophelia is detailed above. An upper level trough is over
the SW N Atlc supporting a pair of troughs that are generating
isolated showers across the Bahamas and central Florida.
Scattered showers and tstms are occurring from 27N-31N between
62W-67W. Farther east, a weaker surface trough is noted from
28N53W to 22N61W supportin isolated showers within 30 nm either
side of its axis. The remainder of the central and eastern Atlc
outside of the influence of Hurricane Ophelia...is under the
influence of surface ridging anchored by a 1019 mb high centered
near 25N45W.

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

$$
Ramos
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