000
ABNT20 KNHC 112353
TWOAT 

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Sat Sep 11 2021

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

A tropical wave and an upper-level trough continue to produce a 
large area of disorganized showers and thunderstorms over portions 
of southeastern Mexico and the southern and central Gulf of Mexico. 
Upper-level winds are gradually becoming more conducive for 
development, and a tropical depression is likely to form on Sunday 
or Monday while the disturbance moves northwestward and then 
northward near the coast of northeastern Mexico.  Additional 
development will be possible through the middle of next week if the 
system remains over water, and interests along the western and 
northwestern Gulf coast should monitor the progress of this system.  
An Air Force Hurricane Hunter aircraft is scheduled to investigate 
the system tomorrow, if necessary.

Regardless of development, this disturbance will continue to produce 
heavy rain across portions of southern Mexico, including the western 
Yucatan Peninsula, through tonight which may lead to flash flooding 
and mudslides. By late Sunday, heavy rain is expected to reach 
portions of the Texas and Louisiana coasts with a heavy rain threat 
then continuing across those coasts through the middle of next week. 
Localized significant rainfall amounts are possible, potentially 
resulting in areas of flash, urban, and isolated river flooding.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

Showers and thunderstorms remain poorly organized in association 
with a tropical wave located near the Cabo Verde Islands. 
Environmental conditions are currently conducive for development, 
and a tropical depression could still form this weekend or early 
next week while the system moves westward over the far eastern 
Atlantic. By the middle of next week, stronger upper-level winds and 
marginally warm ocean temperatures are expected to limit additional 
development. Regardless of development, this disturbance is likely 
to bring gusty winds and locally heavy rain across the Cabo Verde 
Islands tonight.
* Formation chance through 48 hours...medium...50 percent. 
* Formation chance through 5 days...medium...50 percent.

A non-tropical area of low pressure is located over the far 
northeastern Atlantic several hundred miles northeast of the 
Azores. This system is forecast to move south-southeastward towards 
warmer waters, which could allow the low to gradually acquire some 
tropical or subtropical characteristics by the middle of next week.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

Another tropical wave is expected to move off the west coast of 
Africa in a few days. Gradual development of this system is possible 
thereafter, and a tropical depression could from by the middle of 
next week while it moves westward across the eastern tropical 
Atlantic Ocean.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent.

An area of low pressure is expected to form near the southeastern 
Bahamas in a few days resulting from moisture by a tropical wave 
interacting with an upper-level trough. Gradual development of this 
system is possible thereafter as it moves northwestward across the 
western Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

$$
Forecaster Papin