THE WEATHER BEAT · OCT 21

Southwest flood watches widen to Southern California and New Mexico, with an Enhanced severe risk on Arizona's Mogollon Rim

Flood Watches now run from Santa Barbara County to the eastern San Juan Mountains, and the Storm Prediction Center has an Enhanced risk on the Mogollon.

By the Weather Rock October 21, 2026, 8:19 a.m. · 5 min read

Key points

The Flood Watches that began in Arizona and Utah on Tuesday now reach Santa Barbara and Kern counties in California, the Malibu coast, western New Mexico and the eastern San Juan Mountains of Colorado, from the NWS offices that issued them on Wednesday morning.
Several offices put the same cause in their own words: a strong Pacific system drawing moisture into the Southwest. Los Angeles/Oxnard says rain rates of 0.50 to 1.00 inch an hour are possible, heaviest Wednesday night.
As of its Day 1 outlook, the Storm Prediction Center has an Enhanced risk of severe thunderstorms along the Mogollon Rim in Arizona today.

What changed overnight

Tuesday's story was the interior Southwest: Arizona, southern Utah and southwest Colorado. By Wednesday morning the watches had spread west to the California coast and east across New Mexico. Hanford, Los Angeles/Oxnard, Albuquerque and Pueblo each have a Flood Watch in force. Phoenix, Tucson, Flagstaff, Las Vegas, Salt Lake City and Grand Junction still carry the ones described Tuesday, now reworded as "continues to be possible".

In California, the Hanford text says the flooding would come from storms training over the same area, through Thursday evening, in the Bakersfield and Kern River Valley areas. The Los Angeles/Oxnard text covers the Santa Barbara County coast and mountains, and the Santa Monica Mountains and Malibu coast, and warns of extensive street flooding and flooding of creeks and rivers. In New Mexico, Albuquerque describes "repeated rounds of widespread showers and thunderstorms" from a "potent Pacific storm system" drawing "anomalously high moisture" into the Desert Southwest. Pueblo's watch covers the eastern San Juan Mountains and Upper Rio Grande Valley into Friday afternoon, and notes that sub-tropical moisture will bring periods of moderate to heavy rain Wednesday night into Thursday.

The watches, by office

Office	Area	Starts	Ends
Hanford CA	Bakersfield, Kern River Valley, Tehachapi, Grapevine	Wed 8 a.m. PDT	Thu evening
Los Angeles/Oxnard CA	Santa Barbara County; Malibu and Santa Monica Mountains	Wed 8 a.m. PDT; Wed 4 p.m. PDT	Thu 4 p.m. PDT
Albuquerque NM	Western, central and north-central New Mexico	Wed noon MDT	Thu night, 6 a.m. Fri MDT
Pueblo CO	Eastern San Juan Mountains, Upper Rio Grande Valley	Wed noon MDT	Fri 6 p.m. MDT
Phoenix AZ	Valley, Tonto Basin, Globe	Wed 11 a.m. to 2 p.m. MST	Thu 5 to 11 p.m. MST
Grand Junction CO	Four Corners, southeast Utah	Wed noon MDT	Fri noon MDT

*Times are local to each office. Source: NWS Flood Watch products sent between 11:43 p.m. MST Tuesday and 5:04 a.m. PDT Wednesday, October 21. Hanford's WHEN line reads "through Thursday evening". Its machine-readable end time is Thursday 8 p.m. PDT, which is how it is listed here. The Phoenix and Tucson expiry fields read Wednesday morning, earlier than their WHEN lines. The table follows the WHEN lines and the product end times.*

Today, officially

As of the Storm Prediction Center's Day 1 outlook, severe thunderstorms with large hail, severe wind gusts and a couple of tornadoes are possible along the Mogollon Rim in Arizona today. The highest category in the text is Enhanced. The same outlook says marginally severe gusts and an isolated tornado threat are possible along the southern and central California coast. Both are outlook language, not reports of anything that has happened.

What a watch means here

A Flood Watch says conditions favor flooding. It does not say flooding has begun, and none of these products says where the heaviest band will land. The Weather School page on watches, warnings and advisories explains the steps above a watch. Tuesday's story has the Arizona and Utah detail.

This is a morning summary, not emergency information. For live warnings see weather.gov and your local officials.