000 WTPZ43 KNHC 130233 TCDEP3 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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