Storms Bring Relief to California, Drought Expands in the Desert Southwest

A series of powerful Pacific storms have brought significant rain and snow to Northern California, offering much-needed relief from drought conditions. However, the Desert Southwest continues to face worsening drought, according to the latest report from the National Drought Monitor, released on November 26, 2024.

California’s Rainy Relief

In a dramatic shift, Northern California has been drenched by several storms, delivering substantial rainfall and heavy mountain snow. One station northwest of Santa Rosa reported an astounding 24 inches of rain over a seven-day period. As a result, drought conditions across the Pacific Northwest and parts of Northern California have been alleviated, with some areas seeing short-term dryness reduced.

This rainfall has also significantly improved the state’s reservoir levels. California’s two largest reservoirs—Lake Shasta and Lake Oroville—are now at 111% and 105% of their historical averages for this time of year, a major improvement after years of drought. Additionally, snowpacks in the northern and central Sierra have been replenished, with snow water equivalent (SWE) levels now above normal. The Lower Colorado region, which includes parts of California, has also seen a boost, with SWE levels reaching 127% of normal by November 25.

Southwest Drought Worsens

In contrast, the Desert Southwest is experiencing deepening drought conditions. Areas of extreme drought have expanded in northwestern Arizona and into southern Nevada, driven by both short-term precipitation deficits and record heat over the past six months.

In Arizona, reservoir levels are concerning. The Salt River system is 75% full, and the Verde River system is at 57% capacity. Overall, the system is at 73% full, down from 81% at this time last year. The situation is even more dire in the region’s key water sources: Lake Powell is just 37% full, and Lake Mead is at a mere 32% capacity—about half of its average for this time of year. The Lower Colorado system is at 42% full, slightly down from 43% last year. In New Mexico, the largest reservoir along the Rio Grande is only 7% full, a mere 17% of its average capacity, underscoring the severity of the drought in the region.

Snowpack and Future Outlook

Snowpack levels in parts of the West have shown some improvement, which could be a promising sign for future water supplies. The Upper Colorado region, which affects Colorado and parts of Wyoming, has snow water equivalent (SWE) levels at 96% of normal, while the Great Basin, including Utah, reports SWE levels at 125% of normal.

Looking ahead, the National Weather Service’s Weather Prediction Center forecasts light to moderate precipitation over the next week in the Intermountain West, including the Colorado Rockies and central and southern Utah. However, the Climate Prediction Center’s six-to-ten-day outlook suggests a moderate to high probability of above-normal temperatures and below-normal precipitation across much of the West, which could continue to exacerbate drought conditions in the Southwest.

The Potential Impact of La Niña

The situation may worsen with the potential development of La Niña conditions. The Climate Prediction Center’s ENSO Diagnostic Discussion, issued on November 14, indicated a 57% chance that La Niña will develop between October and December and persist through January-March 2025. La Niña conditions are often associated with drier winters in the Southwest, which could further intensify the drought in the coming months.

Communities Brace for Challenges

The expanding drought in the Southwest raises concerns for farmers, ranchers, and water managers. Reduced water availability could impact agricultural production and increase the risk of wildfires. The report highlights how persistent dry conditions and record warm temperatures have intensified the drought in the region.

Meanwhile, the storms in California bring some hope. Improved reservoir levels and snowpacks provide a buffer against future dry spells, though experts caution that several storms will not erase years of drought. Continued water conservation and efficient water management will be essential in the months ahead.

A Tale of Two Extremes

The West is experiencing a tale of two extremes: Northern California has been revitalized by rainfall and snow, while the Desert Southwest faces intensifying drought and dwindling water resources. The coming months will be critical in determining how these states navigate the challenges posed by these contrasting weather patterns.

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