National Weather Service United States Department of Commerce

Excessive Rainfall and Flooding Threat in the South; Hazardous Heat in the Western U.S. Expanding to the Northern Plains

Multiple rounds of heavy rain and thunderstorms across portions of the Texas and Louisiana Coast will likely lead to flash, urban, small stream and river flooding. An additional heavy rainfall threat will exist from the Lower Mississippi Valley through the southern Mid-Atlantic. Meanwhile, a dangerous heat threat will continue across the Western U.S. and northern Plains through Thursday. Read More >

The Climate Prediction Center has issued an El Niño Watch. Though conditions are currently neutral, there is a 62% chance of an El Niño developing during the May to July time period. The range of possibilities toward the end of the year includes a 40% chance of a strong El Niño to a 10% chance of no El Niño. 

El Niño is an area of above-average sea surface temperatures in the central and eastern tropical Pacific Ocean.  Over Indonesia, rainfall tends to become reduced while rainfall increases over the tropical Pacific. The low-level surface winds, which normally blow from east to west along the equator, instead weaken or, in some cases, start blowing the other direction. These changes over the tropical Pacific can effect atmospheric circulations that then translate through the atmosphere and affect weather patterns far away from the tropics.

For more information on El Niño and La Niña, see our 1-Stop El Niño/La Niña page.