A hurricane warning now covers Mexico’s Pacific coast from Punta San Telmo to Punta Mita, and the National Hurricane Center expects Hurricane Simon to reach Category 4 strength before the core approaches the coast on Saturday. At 9 p.m. CST on Thursday, Oct. 8, Simon had 75 mph sustained winds and a central pressure of 985 millibars, and the forecast peak is 120 knots, or 140 mph.
The warning grew between advisories. Six hours earlier, at Advisory 6, it ran only from Punta San Telmo to Playa Perula, when Simon was still a 70 mph tropical storm.
Hurricane warning from Punta San Telmo to Punta Mita
The 9 p.m. CST Public Advisory 7 lists a Hurricane Warning from Punta San Telmo to Punta Mita, which Mexico’s government upgraded from a hurricane watch that had covered Playa Perula to Punta Mita. East of the warning, a Tropical Storm Watch runs from Punta San Telmo to Lazaro Cardenas. Tropical-storm conditions are possible in the watch area beginning Friday, according to the advisory, which also lists the storm’s motion as west-northwest and turning northwest by early Friday.
Inside the warning, the advisory expects tropical-storm conditions on Saturday morning and hurricane conditions on Saturday afternoon or evening. Dangerous storm surge is possible along the immediate coast near and east of the expected landfall point, with large and destructive waves.
The center sat at 15.6 degrees north, 104.6 degrees west, about 235 miles south of Manzanillo and 340 miles south-southeast of Cabo Corrientes, creeping west-northwest at 6 mph. Hurricane-force winds extend 15 miles from the center and tropical-storm-force winds 90 miles. Those radii describe a compact core, so the strongest winds will be confined to a narrow part of the warned coastline.
A Category 4 forecast built on rapid intensification
Forecaster Roberts wrote in the 9 p.m. CST forecast discussion that rapid intensification is expected to begin Friday. The statistical guidance, the SHIPS rapid-intensification index, gives about a 70 percent chance of a gain of 30 knots in 24 hours. The track table steps Simon up from 65 knots at the start to 85 knots at 6 a.m. CST Friday and 100 knots 12 hours later, topping out at 120 knots at 6 a.m. CST Saturday.
That peak is inside Category 4. The Saffir-Simpson scale defines Category 4 as 130 to 156 mph sustained winds and says catastrophic damage will occur: well-built homes can lose most of their roof structure and some exterior walls, most trees and power poles come down, and outages can last weeks to months. Category 3, the bottom of the major-hurricane range, begins at 111 mph, so even a one-category miss on the forecast would leave Simon a major hurricane with devastating damage expected at landfall under the same scale. The NHC’s scale also stresses that it rates wind only, leaving surge and rain outside the category.
The earlier tropical weather discussion, issued at 1605 UTC Thursday with Simon at 55 knots and 995 millibars, already called for a very dangerous Category 4 hurricane before the storm reaches the coast. The forecast has held across three products while the storm itself gained 10 knots, from 55 to 65.
Track, timing and the odds at Manzanillo
Simon is forecast to turn northwest early Friday and then north by early Saturday, with the core approaching the coast of southwestern and west-central Mexico on Saturday. The advisory gives no exact landfall point or time, and Discussion 7 does not name a landfall location. Its table has the center at 19.0 north, 105.3 west at 6 p.m. CST Saturday with 110 knots, and inland at 20.4 north by 6 a.m. Sunday with winds down to 75 knots.
The NHC’s wind speed probabilities, computed with Advisory 6 at 2100 UTC Thursday when Simon was a 70 mph storm, put the cumulative chance of hurricane-force winds at Manzanillo at 35 percent, Barra de Navidad at 26 percent and Puerto Vallarta at 4 percent. Those percentages predate the upgrade to a hurricane and the westward extension of the warning, so the next set of probabilities will reflect a stronger storm and a longer warning. Manzanillo carried the highest figure in that product, with the chance building from Saturday morning and holding through the five-day window.
Rain is a separate threat on the same timetable. The advisory carries 8 to 15 inches over portions of southwestern Mexico through Sunday, with isolated totals of 15 to 25 inches in Michoacán, Colima and Jalisco, and warns of life-threatening flooding and mudslides in steep terrain.
Two more NHC products were due overnight, an intermediate advisory at midnight CST and a full advisory at 3 a.m. CST, and the NHC home page was headlined “Simon becomes a hurricane” with “rapid intensification forecast” at the time of Advisory 7. The unresolved piece is which coastal segment takes the eyewall: the advisory’s 15-mile hurricane-force radius is small next to a warning that spans from Punta San Telmo to Punta Mita, and the forecast gives no landfall point.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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