Northern Lights May Return Tonight — Clouds Could Obscure the Show Across California

Northern lights may return to California tonight

California residents who missed this week's rare aurora may get another chance after sunset tonight, but cloud cover could limit viewing across much of the state.

What happened so far

Two strong geomagnetic storms from the sun painted Tuesday night's sky deep pink and bright orange, making the aurora borealis visible in parts of the Bay Area — including Napa, Contra Costa and Alameda counties. The aurora is typically confined to higher latitudes, so sightings this far south are uncommon and noteworthy.

Another storm is arriving

Forecasters expect a third geomagnetic storm to arrive around midday and remain active into the evening. The National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC) said the aurora could appear "over much of the northern half of the country, and maybe as far south as Alabama to Northern California" this evening.

'The (aurora) forecast is looking pretty good,' said Travis Rector, an astrophysicist at the University of Alaska Anchorage. 'I would definitely take the time to go and look.'

Clouds may spoil the view

An incoming weather system is expected to produce heavy cloud cover across much of California, including the Bay Area and the coast. "It will be a pretty rough night for cloud cover," said Greg Porter, senior newsroom meteorologist at the Chronicle. He added that clearer windows might appear over the Central Coast, the southern Central Valley and the southern Sierra.

Even where skies clear, the red hues that often accompany geomagnetic storms can be faint to the naked eye. Rector warned observers to watch for a 'reddish hazy color' that can blend into cloud or fog. He noted that camera sensors — including many smartphone cameras — are often better at capturing that red glow than human eyes.

The storm's strength and what it means

Space weather experts say this week's third event — a coronal mass ejection (CME) — is expected to be the strongest of the three. Shawn Dahl, service coordinator at the SWPC, said in a video posted to X that the storm was 'traveling significantly faster' and could 'pack even a stronger punch' when it peaks.

As the sun nears the peak of its roughly 11-year solar cycle, eruptions such as CMEs, sunspots and solar flares become more frequent. Severe space weather can disrupt satellites and systems that underpin navigation and communications; the last widely cited disruption occurred in 1989, when a geomagnetic storm knocked out a power grid in Quebec. Don Hampton, a space science professor at the University of Alaska Fairbanks, noted that forecasting has improved since then.

'Space weather sounds very 'woo-woo,' but it's actually very important in our modern lives because we all rely on satellites and power grids,' Hampton said. 'We've learned when we get these predictions to take steps to take care of it.'

Viewing tips

If you plan to look for the aurora: choose a dark location with an unobstructed view to the north, allow your eyes to adjust to the dark for 10–20 minutes, and try taking photos — phone cameras and longer exposures often reveal the red glow more clearly than the naked eye. If possible, use a tripod or steady surface and turn off flash.

Bottom line: A strong geomagnetic storm could make the northern lights visible as far south as Northern California tonight, but cloud cover will likely limit sightings for many. If skies clear where you are, look north and try photographing the sky — your camera may show more than your eyes can.