Tropical Weather Discussion
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AXNT20 KNHC 230606

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
206 AM EDT Wed Aug 23 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.


As of 23/0300 UTC, a tropical wave extends from 26N91W to 17N91W
moving NW at 10 kt. The remnant circulation of Harvey continues
to be analyzed as a 1009 mb low pressure along the wave axis over
the Bay of Campeche near 21N91W. Scattered moderate to isolated
strong convection is from 15N-24N between 88W-92W. Environmental
conditions are conducive for a tropical depression or tropical
storm to form on Wednesday or Thursday while the low moves
northwestward across the western Gulf of Mexico, possibly reaching
the northwestern Gulf coast on Friday. Regardless of development,
this system is likely to slow down once it reaches the coast,
increasing the threat of a prolonged period of heavy rainfall and
flooding across portions of Texas, southwestern Louisiana, and
northeastern Mexico into early next week. This system could also
produce storm surge and tropical storm or hurricane force winds
along portions of the Texas coast later this week, and interests
from northeastern Mexico to southwestern Louisiana should continue
to monitor its progress. A gale warning has been issued for the
SW and west-central Gulf beginning Wednesday morning. See latest
NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02
KNHC and the Tropical Weather Outlook under AWIPS/WMO headers
MIATWOAT/ABNT20 KNHC for more details.


A tropical wave extends from 22N32W to a 1011 mb low within the
monsoon trough located near 15N34W to 10N35W, moving W at 15-20
kt. Satellite imagery indicates a large area of cloudiness in
association with this wave, but convection is limited. This wave
remains in a very moist area based on TPW imagery and has a well
pronounced 700 mb trough.

A tropical wave is moving across the central Caribbean and
extends from SW Haiti near 19N74W to N Colombia near 10N74W
moving W at 20-25 kt. An area of showers is noted near the
northern end of the wave axis. The wave is also producing
scattered moderate to strong convection over northern Colombia.
The wave coincides with a 700 mb trough, and is well depicted in
the moisture product.


The monsoon trough extends from 14N17W to 17N28W to 15N34W to
08N45W to 09N53W. The Intertropical Convergence Zone axis
continues from 09N53W to 09N60W. Besides the convection mentioned
in the tropical wave section, scattered moderate to strong
convection is along the coast of W Africa from 07N-15N between
13W-23W. Scattered moderate convection is from 09N-14N between
27W-32W, and from 08N-11N between 35W-43W.



Attention remains focused on the remnant circulation of Harvey
currently located over the Bay of Campeche. Please, see Special
Features section for details. A gale warning has also been issued.
As of 23/0300 UTC, a surface trough extends from the Florida NE
coast near 30N80W to S Florida to the SE Gulf of Mexico near
25N83W. Scattered moderate to isolated strong convection is over
the SE Gulf from 23N-26N between 80W- 84W. In the upper levels, an
upper level low is centered over the NW Gulf near 28N93W
enhancing showers. Expect over the next 12 hours for the upper
level low to dissipate. Also expect convection over S Florida
within the next 48 hours due to the trough.


A tropical wave is moving across the central Caribbean Sea.
Please, see Tropical Waves section for details. The most recent
scatterometer data provide observations of fresh to locally strong
SE winds across the NW Caribbean mainly N of 20N W of 83W.
Similar wind speeds are noted over the central Caribbean. Strong
trade winds are forecast to pulse off the coasts of northeast
Colombia and northwest Venezuela in the wake of the tropical wave
currently located along 74W. A surface trough over the Atlantic
extends to near Barbados in the Windward Islands producing
isolated showers. Moisture associated with this trough will affect
mainly the Leeward Islands tonight and Wednesday, reaching the
UK/US Virgin Islands by Wednesday night. This will increase the
chance for showers with isolated tstms across the islands.


Scattered showers are observed over Haiti due to a tropical wave.
Daytime heating, local sea breezes and mountain upslope lifting
will continue to combine with available moisture to produce
scattered showers and thunderstorms mainly during the afternnon
and evening hours.


A tropical wave is over the tropical Atlantic. Please see above.
Isolated moderate convection is over the northern and central
Bahamas. Any development of this system during the next few days
should be slow to occur while it drifts over Florida and the
adjacent waters. Farther east, a surface trough extends from
31N63W to 26N67W. Scattered showers are within 90 nm of the
trough. Another surface trough extends from 27N58W to 20N56W to
Barbados near 13N59W. Scattered moderate convection is from 24N-
28N between 54W-56W. A 1021 mb high is centered over the central
Atlantic near 33N48W. An upper-level low is also centered near

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