Remnants of new Pacific storm might contribute to development in the Gulf next week

Pacific Tropical Storm Agatha has formed off the coast of southern Mexico. It’s forecast to make landfall as a Category 2 hurricane in mountainous Oaxaca State late Sunday night or early Monday.

While Oaxaca has been impacted by tropical systems including a few hurricanes in the past, including Hurricane Carlotta in 2012, previous storms have more or less paralleled the Pacific coastline. Agatha, on the other hand, is forecast to make landfall perpendicular to the coast and slam into the mountains that rise just inland.

The coastal plain of Oaxaca state is populated, but relatively lightly so. There will be danger there from the Agatha’s strong winds. But the big threat will be from mudslides caused by torrential rain over the mountains early next week.

Agatha’s circulation is likely to die over those tall mountains, but the upper-level circulation may well cross Mexico and end up at least partially over the water on the Gulf of Mexico side of the mountains.

A broad area of low pressure is forecast to form around the middle of next week over Central America and the extreme southern Gulf of Mexico. This feature is common during the first and last part of the hurricane season. Sometimes an organized tropical system develops out of these large areas of disturbed weather.

We’ll watch for the possibility of a dip in the jet stream coming along, which could lift a piece of that large disturbance east or northeast into the warm Gulf of Mexico.

Nothing is imminent, and the weather pattern over the Gulf is forecast to remain fairly hostile to development, but plan to check in next week to see what happens after Agatha dies over the Mexican mountains.

Here are the Key Messages from the National Hurricane Center for residents of Oaxaca state in southern Mexico:

1. There is an increasing risk of tropical-storm-force and hurricane-force winds along portions of the southern coast of Mexico in the next two to three days, and a Hurricane Watch is now in

effect for portions of this area. Interests in this area should closely monitor the progress of this system and updates to the forecast.

2. Heavy rains associated with Agatha will develop over portions of southern Mexico by Sunday and continue through Tuesday. This will pose a threat of potentially life-threatening flash flooding and mudslides.