Overview

• Conagua and SMN are monitoring a low south of the Suchiate River moving west‑northwest with about a 30–40% chance of development in 48 hours and roughly an 80% probability within seven days.
• If the system organizes it would be named Mario, and early guidance points to possible effects along the Pacific coast from Jalisco to Guerrero around September 14–16, though no track is set.
• A multi‑system setup involving the Mexican monsoon, Tropical Wave 31, a mid‑level cyclonic circulation and Cold Front No. 2 is generating widespread storms with risks of flooding, landslides and electrical activity.
• SMN forecasts very heavy rain of 75–150 mm in Oaxaca and Chiapas today, with strong to very strong rains across numerous states and elevated surf along the coasts of Oaxaca and Chiapas.
• Civil‑protection agencies issued regional alerts, including Mexico City advisories for rain from 19:00 and landslide warnings, while the northwest contends with extreme heat up to 45 °C in Baja California and Sonora.