000
AXNT20 KNHC 231047
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
647 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 0600 UTC surface analysis and satellite imagery through 
1015 UTC.

...SPECIAL FEATURES...

As of 23/0900 UTC, a tropical wave extends from 26.5N92W 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 21N92W. Scattered moderate to 
isolated strong convection is from 20N-24N between 89W-93W. 
Environmental conditions are conducive for development, and a 
tropical depression or tropical storm is very likely to form today
or tonight while the low moves northwestward across the western 
Gulf of Mexico, possibly reaching the northwestern Gulf coast late
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 Tropical Storm or Hurricane 
Watches could be required later today for portions of the coast of
northeastern Mexico, Texas, and southwestern Louisiana. Interests
in these areas should monitor the progress of this system, and 
refer to products issued by your local National Weather Service 
office for more information. An Air Force Reserve reconnaissance 
aircraft is schedule to investigate the low this morning. A gale 
warning has been issued for the SW and west- central Gulf. 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. 

...TROPICAL WAVES...

A tropical wave extends from 23N33W to a 1011 mb low within the 
monsoon trough located near 18N35W to 10N36W, moving W at 15 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 19N75W to N Colombia near 07N75W moving W at 20 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. 

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from 14N17W to 17N30W to 18N35W to 
09N47W. The Intertropical Convergence Zone axis continues from 
09N47W to 08N59W. Besides the convection mentioned in the 
tropical wave section, scattered moderate to strong convection is 
along the coast of W Africa from 08N-14N between 16W-23W. 
Scattered moderate convection is from 09N-14N between 27W-32W, and
from 08N- 11N between 35W-43W. 

...DISCUSSION...

GULF OF MEXICO...

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 been issued. As 
of 23/0900 UTC, a surface trough extends from the Florida NE 
coast near 30N80W to S Florida to a 1013 mb low over the SE Gulf 
of Mexico near 25N82W. Scattered showers are 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 06 hours for the upper level low to 
dissipate. Also expect convection over S Florida within the next 
48 hours due to the trough. 

CARIBBEAN SEA...

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 75W. 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 today, reaching the UK/US Virgin 
Islands tonight. This will increase the chance for showers with 
isolated tstms across the islands.

...HISPANIOLA...

Mostly fair weather is presently over the island. 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 today. 

ATLANTIC OCEAN...

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 25N57W 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 
28N59W. 

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

$$
Formosa