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Tropical Depression Mario Discussion Number   6
NWS National Hurricane Center Miami FL       EP132025
900 PM CST Fri Sep 12 2025

The low-level center of Mario was apparent this afternoon near the 
convective mass just off of the coast of southwestern Mexico. Since 
that time, satellite imagery shows that a large low-pressure area is 
developing to the south of Mario, with vorticity centers noted near 
17N 106W and 15N 103W. This is causing the small circulation of 
Mario to lose its identity as it seems to be becoming a part of the 
larger circulation.  In addition, the convection near the center has 
decreased during the past several hours, and there has been a 
corresponding decrease in satellite intensity estimates. Based on 
these developments, Mario is downgraded to a tropical depression 
with an initial intensity of 30 kt.

The dynamical models show several possible scenarios for the 
evolution of Mario during the next few days. The ECMWF and Canadian 
models show the system dissipating as it becomes absorbed into the 
larger low during the next day or two. The UKMET does not absorb 
Mario into the low, but shows it degenerating into a trough and 
moving northwestward and then westward around the north side of the 
low. The GFS, in contrast, uses the Mario circulation to become the 
center of the larger low, although it keeps the winds below 35 kt 
through the forecast period. The regional hurricane models show the 
possibility of a tropical storm re-forming near or west of Socorro 
Island in a few days, although it is unclear whether this 
development is related to the current Mario circulation.  Given 
these scenarios, the current trends, and the previous forecast, the 
new intensity forecast calls for Mario to continue as a depression 
for 36 h before dissipating inside the larger low. However, an 
alternative scenario is that the circulation could degenerate to a 
trough at any time.

The initial motion is 290/13. If Mario manages to maintain its 
identity, it should turn more westward during the next 36 h as it 
moves around the north side of the larger low.
 
 
Key Messages:
1. Heavy rainfall associated with Mario will impact Jalisco and 
nearby areas into Saturday morning, which could result in flash 
flooding, particularly in areas of higher terrain.
 
2. While all coastal watches have been discontinued for Mexico, 
gusty winds are possible elsewhere along the coasts of western 
Guerrero, Michoacan, and Colima through tonight.  Interests in 
these areas should continue to monitor the progress of Mario.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  13/0300Z 18.1N 104.6W   30 KT  35 MPH
 12H  13/1200Z 18.8N 106.3W   30 KT  35 MPH
 24H  14/0000Z 19.2N 108.0W   30 KT  35 MPH
 36H  14/1200Z 19.7N 109.7W   30 KT  35 MPH
 48H  15/0000Z...DISSIPATED
 
$$
Forecaster Beven
 
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