Multiple M-class solar flares and CMEs, possible CME impact on December 27

Multiple M-class solar flares and CMEs were recorded on December 24, 2023. Forecasts indicate potential geomagnetic disturbances with a grazing blow expected late on December 27, 2023.

Solar activity has increased to moderate levels, marked by several M-class flares over the last 24 hours leading up to 00:30 UTC on December 25, 2023.

The flares erupted mainly from Region 3529, including an M2.9 flare at 11:18 UTC on December 24 and an M2.6 flare at 16:49 UTC. Another notable M1.1 flare was detected from a region just beyond the southeast limb. Despite the flaring, most spot groups remained stable, with Region 3530 showing signs of growth.

Additionally, an approximately 22-degree filament eruption centered near N48W35 began lifting at 09:20 UTC on December 24, leading to a Coronal Mass Ejection (CME) observed in SOHO/LASCO coronagraph imagery by 12:24 UTC. Initial analyses suggest a possible grazing impact from this CME by late on December 27. Another CME of interest, resulting from a filament eruption near S20E48 at 14:38 UTC, was observed off the southwest limb. Analysis of this event is still in progress.

In terms of solar radiation, the greater than 2 MeV electron flux maintained normal to moderate levels, with the greater than 10 MeV proton flux remaining at background levels. These conditions are expected to persist through December 27.

Solar wind parameters were mildly disturbed over the past 24 hours. Wind speeds fluctuated between 364 – 468 km/s, while total magnetic field strength and the Bz component varied within typical ranges. Mostly positive phi angles were recorded.

Looking ahead, nominal solar wind conditions are anticipated for December 25-26, with late December 27 potentially seeing effects from the December 24 CME. As for the geomagnetic field, quiet to unsettled conditions will dominate until late December 27, when the expected CME could stir unsettled to active periods.

References:

¹ Forecast Discussion – Issued: 2023 Dec 25 0030 UTC – Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center

Featured image credit: NASA/ESA LASCO C3, The Watchers