NOAA Reports Severe Solar Storm Sparks Rare Auroras Across Half the U.S.

A powerful solar storm from an X-class flare slammed into Earth on Monday, triggering the most intense solar radiation storm in more than two decades and unleashing auroras that forecasters said could be visible from New York and Washington State down to Alabama and northern California. The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center (SWPC) classified the event as an S4 “severe” radiation storm and a G4 “severe” geomagnetic storm, both level 4 on its 1–5 scale. cnn +1

How Severe Is This Solar Storm — And Who Is on Alert?

The disturbance began with an X1.9-class solar flare that peaked at about 1:09 p.m. EST (1809 UTC) on Sunday, January 18, from active region AR4341, launching a full-halo coronal mass ejection (CME) directly toward Earth. space The CME’s shock front arrived Monday afternoon, with G4 geomagnetic storm levels first reached at 2:38 p.m. EST (1938 UTC), SWPC said. swpc By early evening, NOAA confirmed an S4 radiation storm in progress, the first at that level since the “Halloween storms” of October 2003. swpc +1

Space weather forecasters warned that such storms can increase radiation exposure for astronauts and passengers on polar airline routes, interfere with high‑frequency radio used for transpolar flights, and raise the risk of single‑event upsets and surface charging on satellites. swpc +1 SWPC said it had notified airlines, the Federal Aviation Administration, NASA, the Federal Emergency Management Agency, and North American grid regulators so operators could take precautionary steps. swpc Despite the severity, solar physicist Ryan French said satellite operators were most likely to feel the effects Monday night and that “widespread technology impacts for the general public are not expected.” cnn

A Rare Aurora Opportunity for Half the U.S.

The same geomagnetic turbulence that threatened satellites also set up one of the best aurora-viewing opportunities over the continental United States in years. Forecasts called for planetary Kp indices up to 8 — on a scale that tops out at 9 — enough to drive the auroral oval far south of its usual high‑latitude home. swpc +1 NOAA and multiple media outlets said the northern lights could be visible, weather permitting, across much of Canada and in more than 20 U.S. states, from the Pacific Northwest through the Upper Midwest and New England, and potentially as far south as Alabama and northern California. usnews +2

Skywatchers were advised to seek dark, north‑facing horizons away from city lights during local nighttime hours, with the best chances near midnight and during short, intense bursts known as substorms. foxweather +1 Even where the glow is faint to the naked eye, modern phone cameras on long exposure can capture the display. cnn Local outlets from Minnesota to North Carolina and Northern California issued detailed viewing guides as residents braved cold temperatures and, in many areas, patchy clouds in hopes of seeing the rare spectacle overhead. usnews +2

The Bigger Picture

The storm struck as the sun moves through an active phase of Solar Cycle 25, which has already produced several strong flares and geomagnetic events in recent years. cnn +1 While Monday’s S4/G4 combination fell short of a worst‑case “Carrington‑class” superstorm, it underscored both the vulnerability of modern infrastructure — from precision GPS and satellites to long‑distance power lines — and the growing emphasis on advance space‑weather forecasting and coordinated response. cnn +2 For most people, the event was likely to be remembered less for its technical risks than for a fleeting, colorful ribbon of light far from the Arctic, a reminder that solar activity 93 million miles away can suddenly become local news.