It’s the rain from the plume of Blanca, and it’s going to be bringing clouds to the sky and the chance of floods across the central U.S. and Canada.
Tropical Storm Blanca, which peaked as a Category 4 hurricane, broke up over Baja California Monday. Its moisture arrived in Arizona, New Mexico and parts of California as rain, said Mike Musher, a meteorologist at the U.S. Weather Prediction Center in College Park, Maryland.
Other weather systems will pick it up from there, raising the chance of flash flooding in Nebraska and South Dakota Wednesday and in Iowa, Minnesota and Wisconsin Thursday, the center said.
“It’s not necessarily rare, but not really that common that something so early in the season in the Pacific comes up,” Musher said.
Blanca was the earliest a tropical system hit Baja California in records going back to 1949, Weather Underground co-founder Jeff Masters wrote on his blog. The route from there to the U.S. Southwest is a relatively short one and a path traveled by storms last year as well. Arizona was struck by deadly flooding last summer.
The eastern Pacific hurricane season starts on May 15 and ends Nov. 30. The National Oceanic and Atmospheric Administration predicted 15 to 22 Pacific storms will reach at least tropical storm strength and get names. Last year the basin produced 20 storms, the most since 1992 and five above the annual average from 1971 to 2009 of 15.
The busy season last year was credited to large pools of warm water in the Pacific, meeting one condition of an El Nino pattern that can affect global weather. This year the weather agencies of Australia, Japan and the U.S. agreed an El Nino has begun, meaning the atmosphere has reacted to the warm ocean water. Many forecasters anticipate more storms in both the eastern and western Pacific basins, increasing the chance for tropical moisture to sweep north into the central U.S.
Bianca may be the first of those storms to affect that region. Parts of Iowa and Wisconsin may get 3 inches of rain Thursday and Friday, the National Weather Service said. Any thunderstorms that develop could drop 5 inches of rain.
A few years ago, that kind of rain would have been welcome across the Midwest and upper Great Plains. The drought that gripped the area is long gone now. The central U.S. has been among the wettest parts of the country.
While drought held on in the U.S. West and Northeast, so much rain fell in the middle of the country that May turned out to be the wettest month in the 121-year record for the contiguous 48 states, the National Centers for Environmental Information said Monday.
If the moisture from Blanca turns out to be this summer’s trend, the Midwest and Plains states may end up awash in a sea of plenty. Ideally some of those storms would hug the coast and pour on California, which is almost completely covered by drought.