Full Breakdown
May 10 Solar Flare and CME May Trigger Minor Geomagnetic Storm and Aurora Displays
5/15/2026, 12:20:57 AM
Solar Flare and CME Overview
On May 10 2026 a solar flare of class M5.7 (some reports list it as M5.8) erupted from sunspot region AR 4436 at 9:39 a.m. EDT (1339 GMT). The flare launched a coronal mass ejection (CME) that began traveling outward at roughly 650 km s?¹. Intense X-ray and ultraviolet radiation from the flare caused high-frequency radio blackouts over the Atlantic Ocean.
Sunspot AR 4436 and Recent Solar Activity
AR 4436 has been unusually active, ejecting at least five CMEs while on the Sun’s far side during the preceding week. As the region rotates into Earth’s “strike zone,” the likelihood of Earth-directed eruptions rises. Solar activity remains elevated after the recent solar-maximum peak in early 2025, although a gradual decline is expected.
Timeline and Expected Earth Encounter
The CME left the Sun on May 10 and is forecast to intersect Earth’s orbit between late May 12 and early May 13, according to NOAA’s Space Weather Prediction Center. Some models, citing a later coronal-hole-driven solar-wind stream, extend the possible impact window to the night of May 14-15.
Geomagnetic Forecast and Potential Aurora Visibility
NOAA initially classified the expected disturbance as a G1 (minor) geomagnetic storm, which can produce visible auroras at high latitudes. The U.K. Met Office later upgraded the outlook to G2 in several models, expanding the potential auroral oval. Under a G1 scenario, auroras are likely in Alaska and the northern United States—Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan and Maine. A G2 event could add Oregon, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, New York, Vermont and New Hampshire, as well as Scotland and northern England in the United Kingdom. Minor power-grid fluctuations and limited satellite impacts are also possible.
Official Statements from NOAA, SWPC, and Met Office
NOAA’s Space Weather Prediction Center noted that the CME’s bulk is expected to miss Earth but warned that a glancing encounter cannot be excluded, emphasizing the chance of a minor geomagnetic storm and associated radio disruptions. The Met Office’s aurora forecast warned of a possible enhancement to the auroral oval, especially over northern Scotland, if the CME’s edge reaches Earth. Both agencies stress continuous monitoring through real-time solar-wind data and 30-minute aurora forecasts.
Conflicting Forecasts and Gaps
Sources differ on the flare’s classification (M5.7 vs. M5.8) and on the storm’s severity (G1 vs. G2). NOAA’s early outlook listed a G1 storm for May 12-13, while later Met Office and NOAA updates suggested a G2 level for May 14-15. The timing of the CME’s arrival also varies, with some models predicting a brush on May 12-13 and others a later impact on May 14-15. No definitive measurements of the CME’s magnetic orientation have been released, leaving uncertainty about the exact geomagnetic response.
Verbatim Quotes
- “Modeling of the resulting CME indicates that a bulk of the material should pass well behind Earth's orbit.” — Space Weather Prediction Center spokesperson
- “That being said, a glancing blow and or shock arrival by late on 12 May into the early portions of the 13th … can not be ruled out.” — Space Weather Prediction Center spokesperson
- “There is the potential for a glancing CME arriving into early UTC on 13 May,” — Met Office aurora forecast
- “This may bring an enhancement to the auroral oval perhaps allowing sightings across northern Scotland and similar geomagnetic latitudes, where skies are clear.” — Met Office aurora forecast
Monitoring and Outlook
NOAA and the Met Office will continue issuing 30-minute aurora forecasts and updating geomagnetic indices through the weekend. Observers are advised to seek dark, clear skies during pre-dawn hours for the best chance to view any aurora.
