Southern California and Desert Southwest Expected to Stay Mostly Dry as High-Pressure Ridge Blocks Storms; Possible Pattern Shift Near Christmas

CALIFORNIA — Following a record-wet November across portions of Southern California and the Desert Southwest, weather patterns have taken a noticeable turn. Forecasters report that a dominant high-pressure ridge has shifted the storm track well to the north, leaving the Southwest in an extended stretch of quiet, dry conditions that is expected to last through the next 7–10 days.

This stable ridge pattern has effectively diverted Pacific storms toward the Pacific Northwest, British Columbia, and parts of the Northern Rockies — sparing California, Nevada, Arizona, and surrounding regions from additional early-winter rainfall.

High Pressure Keeps Southwest Calm

The current setup centers a strong ridge over:

• Southern California
• Nevada
• Arizona
• New Mexico

Under this ridge, skies remain mostly sunny, temperatures trend near or slightly above seasonal averages, and rain chances stay minimal. This is a marked contrast from the unusually wet conditions seen in November, particularly in the Los Angeles Basin, Inland Empire, and portions of the Desert Southwest.

Forecasters say this ridge is expected to hold firm for at least another week to week and a half, reinforcing stable weather and keeping major storm systems away from the region.

Storm Track Remains North of the Region

While the Southwest stays quiet, the Pacific Northwest — including Washington, Oregon, and parts of Idaho — continues to receive frequent storm activity, heavy precipitation, and a more active jet stream pattern.
This north-focused storm track has been consistent and is one of the key contributors to the Southwest’s dry spell.

Signs of a Potential Pattern Change Near Christmas

Meteorologists note that there are early signals suggesting a possible breakdown of the ridge pattern during the week of Christmas. If this happens, moisture could return to the Southwest, opening the door to late-December precipitation for:

• Southern California
• Las Vegas area
• Phoenix metro
• Southern Nevada and western Arizona

While timing and strength remain uncertain, a shift could help balance the unusually dry start to December after the exceptionally wet November.

What Residents Should Expect

For now, residents across the Southwest should prepare for:

• Continued dry, calm weather
• Stable temperatures with mild afternoons and cooler nights
• Little to no rain through mid-December
• Increasing attention on potential pattern changes closer to Christmas

Forecasters will continue monitoring model trends closely to determine whether the region may see a return of storm activity before the end of the month.

Stay updated with NapervilleLocal.com as we track developing forecasts and bring you timely updates on weather shifts across the country.