Tropical Weather Discussion
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AXNT20 KNHC 130519

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
119 AM 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 0000 UTC surface analysis and satellite imagery through
0515 UTC.


Hurricane Ophelia is centered near 30.7N 34.7W at 13/0300 UTC or
about 582 nm southwest of the Azores, moving east-northeast at 6
kt. Estimated minimum central pressure is 970 mb. Maximum
sustained wind speed is 90 kt with gusts to 110 kt. Numerous
moderate convection is from 29N-32N between 32W-36W. The center of
Ophelia will remain south of the Azores through Saturday. See the
latest Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22
KNHC for more details.


A tropical wave is over the east Atlantic extending its axis from
16N23W to 04N23W, moving west at about 10-15 kt. The wave is in a
region of strong vertical shear and IR enhanced imagery shows that
the wave is being affected by Saharan dry air and dust. These
environmental conditions are hindering deep convection at this

A tropical wave is in the central Atlantic with axis extending
from 21N52W to 09N57W, moving west at 15-20 kt. The wave is
mainly in a low to moderate vertical shear environment and TPW
imagery depicts the wave is in a region of abundant moisture.
Mid-level diffluence and upper-level divergence support numerous
moderate convection from 10N-20N between 46W-55W.

A tropical wave is in the Caribbean with axis extending from
15N79W to 03N78W, moving west at 5 kt. The wave is mainly in a
low to moderate vertical shear environment and TPW imagery shows
the wave in a region of abundant moisture. At this time, scattered
moderate convection is observed along the southern portion of the
wave where it interacts with the monsoon trough south of 09N.


The monsoon trough extends across inland Africa to 13N19W. The
ITCZ extends from 10N25W to 08N48W. Aside from the convection
associated with the tropical waves, scattered moderate convection
is within 100 nm on either side of the ITCZ between 33W-46W.



A stationary front extends from the Florida panhandle near 30N86W
to 25N95W to 20N96W. Isolated showers are noted along the front.
An upper level low is over the west Atlantic reflected as a
surface trough and generating scattered showers across the
southern portion of the Florida Peninsula and adjacent waters mainly
south of 26N and east of 85W. Gentle to moderate easterly winds
prevail across the basin east of the front. The front is expected
to become diffuse and remain as a surface trough across the
southwest Gulf on Friday.


A mid-to-upper level low is centered over the Bahamas and
extending its trough across Cuba and the far northwest Caribbean.
At the surface, a 1009 mb low is centered near 22N80W with trough
extending from the low to 21N83W. Isolated showers are noted
with these features. A low amplitude tropical wave is moving
across the south-central Caribbean. See the section above for
details. Latest scatterometer data depicts gentle to moderate
trades across the basin. Expect for the low over Cuba to move west
during the next 24 hours.


Fair weather prevails across the island at this time. A mid-to-
upper level high will be over the island through Saturday, thus
supporting fair weather.


Hurricane Ophelia is detailed above. An upper-level low is
centered over the northern Bahamas providing support for a surface
trough analyzed from 29N71W to 23N79W with scattered showers and
thunderstorms focused primarily west of 70W. Farther east, a
weaker surface trough is noted from 28N56W to 20N58W with isolated
showers. The remainder of the eastern Atlantic outside of the
influence of Hurricane Ophelia is under the influence of surface
ridging anchored by a 1022 mb high centered near 38N19W.

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