Alvin To Help Fuel Storms For Parts Of US

The moisture of ex-Tropical Storm Alvin is bound for the Southwest United States this weekend, where it will help to enhance unusual rainfall for this time of year and then go on to help spawn storms in the Central US in the week ahead.

Forecast

Remnant moisture from Alvin in combination with an upper low will help trigger the development of showers and thunderstorms over the Southwest U.S. this weekend, especially by Sunday, including Phoenix and Tucson.

This is a rather unusually wet pattern for the end of May and beginning of June, there. June is typically one of the driest months of the year in this region since it precedes monsoonal rains that arrive later in summer.

Up to an inch of rain could fall across portions of the Four Corners region. Localized flash flooding is possible on Sunday in southern Arizona.

The severe thunderstorm chances also grow from the Dakotas to the Central Plains Monday and Tuesday as Alvin's moisture gets pulled into a sprawling area of low pressure that will pivot from the Central Rockies to the Upper Midwest.

NOAA's Storm Prediction Center has said that severe weather is possible:

- Monday: From eastern Colorado to eastern South Dakota, but strong thunderstorms are also possible in a broader area from the Texas panhandle to northern Minnesota.

- Tuesday: From north Texas to southern Wisconsin, including Kansas City, Tulsa, Amarillo, and Madison, Wisconsin.

The season is beginning: As senior meteorologist Chris Dolce wrote about earlier this month, the Eastern Pacific hurricane season officially begins on May 15, two weeks earlier than the Atlantic hurricane season.

While many Eastern Pacific tropical storms and hurricanes move west-northwest and eventually fizzle in the open ocean, some do strike land, as we saw in 2023 with the remnant of Hurricane Hilary in the Desert Southwest and with Category 5 Hurricane Otis in Acapulco, Mexico.

Sara Tonks is a content meteorologist with weather.com and has a bachelor’s and a master’s degree from Georgia Tech in Earth and Atmospheric Sciences along with a master’s degree from Unity Environmental University in Marine Science.