BULLETIN
Tropical Depression Thirteen-E Advisory Number 2
NWS National Hurricane Center Miami FL EP132025
900 PM CST Thu Sep 11 2025
...TROPICAL DEPRESSION THIRTEEN-E HEADING WEST-NORTHWESTWARD OFF THE
COAST OF SOUTHERN MEXICO...
SUMMARY OF 900 PM CST...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...16.0N 99.6W
ABOUT 65 MI...105 KM SSE OF ACAPULCO MEXICO
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES
Tropical Depression Thirteen-E Discussion Number 2
NWS National Hurricane Center Miami FL EP132025
900 PM CST Thu Sep 11 2025
The satellite appearance of Thirteen-E has improved some since the
previous advisory, with deep convection continuing to burst over or
near the estimated low-level center. The latest subjective Dvorak
current intensity estimates from TAFB and SAB were 2.5/35 kt and
2.0/30 kt. Meanwhile the objective estimates from UW-CIMSS have
ranged from 28 to 35 kt since the previous advisory. Based on a
blend of these data, the initial intensity has been held, perhaps
conservatively, at 30 kt for this advisory package.
The depression is moving to the west-northwest, or 290 degrees, at
10 kt. This general motion is expected to continue for the next
couple days, as the cyclone is steered by a mid-level ridge over
northern Mexico and Texas. A turn toward the northwest along with a
decrease in forward speed is expected over the weekend, as the
system moves along the southwestern periphery of the mid-level
ridge, with that motion continuing through day 5. The official
track forecast lies is very close to the previous advisory, roughly
between the corrected consensus HCCA and AI-Driven GDMI track aids.
The circulation of Thirteen-E remains very small, with an estimated
radius of the outermost closed isobar only 80 n mi, and this may be
generous. In the next couple of days, the global models suggest
that moderate northeasterly vertical wind shear, along with the
proximity to land, should limit the system's ability to intensify
significantly, and the intensity forecast only calls for some slow
strengthening. Over the weekend, environmental conditions should
become more favorable for intensification, as the system will be
farther offshore, over very warm water and surrounded by moist
mid-level air, while vertical wind shear will drop off to light
levels and become aligned with the motion of the cyclone. This
should lead to steady strengthening, with the system forecast to
become a hurricane by 72 hours. By day 5, cooler sea surface
temperatures and drier more stable environment should lead to a
weakening trend. The official intensity forecast lies on the higher
end of the intensity guidance envelope and closest to the AI-Driven
GDMI intensity aid.
Key Messages:
1. Heavy rainfall associated with Tropical Depression Thirteen-E
will impact southern and southwestern Mexico through Sunday, which
could result in flash flooding, particularly in areas of higher
terrain.
2. The depression is forecast to become a tropical storm later
tonight, while moving parallel to the southern and southwestern
coasts of Mexico. While the strongest winds are expected to remain
offshore, gusty winds are possible along portions of the southern
and southwestern coast of Mexico from Punta Maldonado through
Manzanillo during the next day or so. Interests in these areas
should monitor the progress of this system.
FORECAST POSITIONS AND MAX WINDS
INIT 12/0300Z 16.0N 99.6W 30 KT 35 MPH
12H 12/1200Z 16.5N 101.3W 35 KT 40 MPH
24H 13/0000Z 17.1N 103.5W 40 KT 45 MPH
36H 13/1200Z 17.6N 105.5W 45 KT 50 MPH
48H 14/0000Z 18.0N 107.1W 50 KT 60 MPH
60H 14/1200Z 18.4N 108.6W 60 KT 70 MPH
72H 15/0000Z 18.9N 109.9W 70 KT 80 MPH
96H 16/0000Z 20.7N 112.6W 70 KT 80 MPH
120H 17/0000Z 23.0N 114.7W 55 KT 65 MPH
$$
Forecaster Jelsema (CPHC)
Tropical Depression Thirteen-E Advisory Number 2
NWS National Hurricane Center Miami FL EP132025
900 PM CST Thu Sep 11 2025
...TROPICAL DEPRESSION THIRTEEN-E HEADING WEST-NORTHWESTWARD OFF THE
COAST OF SOUTHERN MEXICO...
SUMMARY OF 900 PM CST...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...16.0N 99.6W
ABOUT 65 MI...105 KM SSE OF ACAPULCO MEXICO
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES
Tropical Depression Thirteen-E Discussion Number 2
NWS National Hurricane Center Miami FL EP132025
900 PM CST Thu Sep 11 2025
The satellite appearance of Thirteen-E has improved some since the
previous advisory, with deep convection continuing to burst over or
near the estimated low-level center. The latest subjective Dvorak
current intensity estimates from TAFB and SAB were 2.5/35 kt and
2.0/30 kt. Meanwhile the objective estimates from UW-CIMSS have
ranged from 28 to 35 kt since the previous advisory. Based on a
blend of these data, the initial intensity has been held, perhaps
conservatively, at 30 kt for this advisory package.
The depression is moving to the west-northwest, or 290 degrees, at
10 kt. This general motion is expected to continue for the next
couple days, as the cyclone is steered by a mid-level ridge over
northern Mexico and Texas. A turn toward the northwest along with a
decrease in forward speed is expected over the weekend, as the
system moves along the southwestern periphery of the mid-level
ridge, with that motion continuing through day 5. The official
track forecast lies is very close to the previous advisory, roughly
between the corrected consensus HCCA and AI-Driven GDMI track aids.
The circulation of Thirteen-E remains very small, with an estimated
radius of the outermost closed isobar only 80 n mi, and this may be
generous. In the next couple of days, the global models suggest
that moderate northeasterly vertical wind shear, along with the
proximity to land, should limit the system's ability to intensify
significantly, and the intensity forecast only calls for some slow
strengthening. Over the weekend, environmental conditions should
become more favorable for intensification, as the system will be
farther offshore, over very warm water and surrounded by moist
mid-level air, while vertical wind shear will drop off to light
levels and become aligned with the motion of the cyclone. This
should lead to steady strengthening, with the system forecast to
become a hurricane by 72 hours. By day 5, cooler sea surface
temperatures and drier more stable environment should lead to a
weakening trend. The official intensity forecast lies on the higher
end of the intensity guidance envelope and closest to the AI-Driven
GDMI intensity aid.
Key Messages:
1. Heavy rainfall associated with Tropical Depression Thirteen-E
will impact southern and southwestern Mexico through Sunday, which
could result in flash flooding, particularly in areas of higher
terrain.
2. The depression is forecast to become a tropical storm later
tonight, while moving parallel to the southern and southwestern
coasts of Mexico. While the strongest winds are expected to remain
offshore, gusty winds are possible along portions of the southern
and southwestern coast of Mexico from Punta Maldonado through
Manzanillo during the next day or so. Interests in these areas
should monitor the progress of this system.
FORECAST POSITIONS AND MAX WINDS
INIT 12/0300Z 16.0N 99.6W 30 KT 35 MPH
12H 12/1200Z 16.5N 101.3W 35 KT 40 MPH
24H 13/0000Z 17.1N 103.5W 40 KT 45 MPH
36H 13/1200Z 17.6N 105.5W 45 KT 50 MPH
48H 14/0000Z 18.0N 107.1W 50 KT 60 MPH
60H 14/1200Z 18.4N 108.6W 60 KT 70 MPH
72H 15/0000Z 18.9N 109.9W 70 KT 80 MPH
96H 16/0000Z 20.7N 112.6W 70 KT 80 MPH
120H 17/0000Z 23.0N 114.7W 55 KT 65 MPH
$$
Forecaster Jelsema (CPHC)
