Hurricane Simon reaches 100 mph south of Manzanillo and is forecast to become a major storm by evening

Hurricane Simon was a strengthening storm south of Manzanillo on Friday morning, and the National Hurricane Center told people on Mexico's Pacific coast to finish preparations the same day. Advisory number 9, issued at 9:00 a.m. Central time, or 1500 UTC, placed the centre near 16.0 North, 104.7 West.

That position is about 210 miles, or 335 kilometres, south of Manzanillo, and about 310 miles, or 500 kilometres, south-southeast of Cabo Corrientes. Maximum sustained winds were 100 mph, or 155 km/h. The estimated minimum central pressure was 973 millibars, or 28.74 inches. The storm was moving northwest at about 3 mph, or 6 km/h. A slow turn toward the north was expected during Friday and Friday night.

The centre said Simon was forecast to become a major hurricane by Friday evening and to strengthen further on Saturday. Hurricane-force winds extended outward up to 15 miles, or 30 kilometres, from the centre. Tropical-storm-force winds extended outward up to 80 miles, or 130 kilometres. The wind field is still compact. The rain field is not.

A hurricane warning was in effect from Punta San Telmo, in Michoacan, to Punta Mita, in Nayarit. That stretch includes the coast of Jalisco and Colima, the resort and fishing towns that sit under the forecast track. Reuters reported earlier on Friday that Simon was a Category 1 hurricane with winds of 90 mph and that the centre expected a Category 4 storm by Saturday. The 1500 UTC advisory already had the winds at 100 mph, which is Category 2 on the Saffir-Simpson scale. The next step the centre named was major-hurricane strength, Category 3 or above, by evening.

An earlier discussion, based on the 0900 UTC fix, had put Simon near 15.8 North, 104.5 West, with winds of 80 knots and a central pressure of 978 millibars, moving northwest at 4 knots, with peak seas near 25 feet. The jump to 100 mph and 973 millibars by mid-morning is the rapid intensification the centre had flagged. Rapid intensification is a defined change, a rise of at least 30 knots in 24 hours. The morning advisories were already on that path.

In Jalisco, residents of El Rebalse, in the municipality of Cihuatlan, had been moved as a precaution. Reuters reported that 70 people left on their own and 10 went to a temporary shelter. Governor Pablo Lemus said on X that classes were suspended on Friday and Monday in 22 municipalities. Civil protection authorities asked people on the Pacific coast to watch for small cracks, tilting trees or fences, and water seeping from slopes, because the rain raises the chance of landslides.

The centre said heavy rain from Simon would affect southwestern Mexico through the weekend and could produce life-threatening flooding and mudslides, especially in steep terrain. Private forecaster AccuWeather expected landfall on the southwestern coast early Sunday, with 18 to 24 inches, or 46 to 61 centimetres, possible on the coasts of Jalisco and Colima. The National Hurricane Center directed readers to its storm-total rainfall graphic for the official depiction. Swells were already expected to reach the southwestern and west-central coast through the weekend.

The slow forward speed is the operational problem. A storm moving at 3 mph does not cross a coastal district in an afternoon. It sits. Rain falls on the same slopes for longer. The warning text told residents to rush preparations to completion on Friday, before the turn toward the north and before the evening increase to major-hurricane strength.

Manzanillo is the nearest large port in the advisory's distance line. Cabo Corrientes, farther north, marks the approach to the Bahia de Banderas coast, where Puerto Vallarta sits. The warning runs as far as Punta Mita, at the northern side of that bay. Hotels, fishing harbours and the coast road between those points are inside the zone the centre named.

Simon is the eastern Pacific system. It is separate from Hurricane Isaias, which on the same Friday morning was a Category 3 storm in the Gulf of Mexico, headed for the northern Gulf Coast. Two hurricane warnings were live on opposite sides of Mexico and the United States. The Pacific one is the one that still had a day of slow movement before the forecast landfall window.

The next named change is the evening threshold. If the centre's forecast holds, Simon will be a major hurricane before midnight Central time, still offshore, still moving slowly, with the warning already up from Punta San Telmo to Punta Mita.