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Atlantic Tropical Weather Discussion

AXNT20 KNHC 151815

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
215 PM EDT Mon Oct 15 2018

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 1200 UTC surface analysis and satellite imagery through 
1715 UTC.


A broad area of low pressure, called a Central American Gyre, is 
centered over the southwestern Caribbean Sea near 15N82W. 
Scattered moderate to isolated strong convection is noted from 12N
to 16N between 78W and 84W. There is a medium probability that a 
tropical cyclone may develop within this broad circulation within
the next 48 hours as the system moves westward toawards Central 
America. Regardless of tropical cyclone development, this gyre 
will bring heavy rainfall across portions Central America for the
next several days, including areas that have already had heavy 
rainfall earlier this month. This heavy rainfall will bring the 
potential for flash flooding and mudslides over areas of 
mountainous terrain. Refer to your local meteorological service 
for specific information on this potentially dangerous weather 

A cold front is presently along the Texas coast S of Houston.
Scattered showers are within 90 nm of the front. Fresh to strong
northerly winds behind the front will increase to minimal gale 
force on 17/0000 UTC. The front will then extend from SE Louisiana
to the SW Bay of Campeche. Winds will diminish below gale force 
on 17/1200 UTC.


A tropical wave is just off the coast of W Africa along 18W from
02N-15N, moving W at 15 kt. SSMI TPW imagery shows a distinct
moisture area around the wave axis. Scattered moderate convection
is from 02N-08N between 14W-20W. 

A low amplitude tropical wave extends its axis along 47W from 
01N-15N, moving west at 15-20 kt. A 700 mb trough is shown by 
model analyses with this wave. TPW imagery indicates abundant 
moisture in its environment. Scattered moderate to strong 
convection is occurring from 04N-11N between 44W-50W.

A tropical wave extends its axis along 53W from 08N-21N, moving 
west at 10-15 kt. A 700 mb trough is depicted by model analyses 
with the wave, and there is a local maximum in TPW. It is likely 
that the tropical wave along 47W will be merging with this wave 
over the next 24 hours. Moisture associated with these waves is 
likely to enhance showers and thunderstorms over the Lesser 
Antilles Tuesday into Wednesday, and this activity will spread to 
the eastern Caribbean Sea during the middle of the week.

A tropical wave extends its axis along 64W from 08N-21N moving 
west at 10 kt. Scattered moderate convection is over Puerto Rico.
Scattered showers are noted over the northern Leeward Islands and
Virgin Islands. This wave is expected to dissipate within 24 
hours as it moves toward the central Caribbean.


The monsoon trough enters the eastern Atlantic from the coast of
Africa near 12N17W to 03N30W. The ITCZ extends from 03N30W to 
02N45W. Besides the convection mentioned in the tropical wave
section, scattered moderate convection is from 04N-08N between 


A cold front is presently along the Texas coast S of Houston. The
remainder of the Gulf of Mexico has 10-15 kt SE surface flow. 

An upper-level high is centered over NE Mexico near 22N99W.
Another upper-level high is centered over N Florida near 29N82W. 
Upper-level moisture is over the far W Gulf, and over the SE Gulf. 

Expect the cold front to move slowly SE and extend from central
Florida to the NW GULF near 26N96W to the W Bay of Campeche near
21N96W on Thursday. A brief gale is forecast. See above. 


A tropical wave is over the E Caribbean that is forecast to
dissipate in 24 hours. Two other tropical waves E of the Caribbean 
are forecast to merge and be just E of the Caribbean in 24 hours.

See the special features section about the Cenral Caribbean Gyre. 

An upper level trough extends from the Mona Passage to N Colombia.
Scattered showers are within 120 nm of the trough axis.  


See above about the tropical waves in the tropical Atlantic. 

A stationary front extends across the west Atlantic from 32N56W 
to 29N64W to 30N70W. A surface trough continues W to 29N78W to
31N80W. Scattered showers are within 90 nm of the front and 

A 1026 mb high is centered over the W Atlantic near 38N66W.
Another 1025 mb high is centered over the E Atlantic near 33N33W. 

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