A powerful “pineapple express” atmospheric river — a plume of tropical moisture stretching from near Hawaii — is set to drench Southern California and the Desert Southwest right over Halloween weekend, forecasters warned on Friday.
The storm arrives in two rounds. On Friday, heavy rain hits western Texas, parts of New Mexico and Arizona. The main event targets Southern California from Saturday, peaking early Sunday, with rain lingering into Monday across the Southwest.
The flash-flood threat is serious because the ground is already saturated. Last week’s storms dropped 2 to 5 inches of rain across the region, triggering major flash flooding in northern Arizona, New Mexico, southern Colorado and southern Utah. Rivers like the Little Colorado and Verde could run high for days after the weekend soaking, according to the National Weather Service in Flagstaff.
Total moisture over parts of Arizona, Colorado, Nevada and Utah could reach 2 to 3 times the normal October average — near-record levels for a Halloween weekend. Areas of greatest concern include Phoenix’s north and east sides, the Mogollon Rim, southern Utah canyonlands, wildfire burn scars, and lower elevations of western Colorado.
The system is tied to the strong El Niño winter of 2026-27, which forecasters say is loading the pattern with moisture. The same cross-country storm system has already affected roughly 35 states this week with rain, snow and severe weather — and Halloween weekend could bring its most dramatic chapter yet.
Read also: USA weather October 26: snow and thunderstorms hit 16 states and Southwest severe storms bring flash flood risk
Bhudev Bhagaliya is an experienced and senior journalist who has carved a distinct niche for himself in the world of Hindi journalism through his profound understanding and precise writing style. With over two decades of experience in the field of journalism, he has held key responsibilities at Dainik Hindustan for 12 years and at Amar Ujala for one year. Currently, he serves as the Content Editor for the Jagrook Youth News newspaper and portal, where he plays a crucial role in ensuring the quality and credibility of the news content. Bhudev Bhagaliya consistently writes about issues that help raise awareness within society and among the younger generation.