ARRL Solar Report February 5, 2026

Solar activity was at high levels for most of the week, dominated by Region 4366. The most notable event was an impulsive X4.2 flare from that region on February 4. Throughout the period, Region 4366 continued to exhibit a slight reduction in area and a modest simplification of its magnetic complexity. Region 4369 developed trailing spots while Regions 4370 and 4372 decayed in extent and complexity and became unipolar spot groups. The remaining numbered regions on the visible disk remained stable or in a state of slight decay.

Three eruptions were observed in coronagraph imagery during the period. First was a coronal mass ejection (CME) off the SE limb, first observed in C2 imagery on February 4, and was likely associated with flaring near Regions 4370 and 4371. This event was followed by post-eruptive arcades also on February 4 at the same location, which further confirmed the source region despite flare activity being partially obscured by Region 4366. Modeling indicates no Earth-directed component.

The second was a narrow eruption to the NNW, first seen in C2 imagery on February 4. While potentially associated with the aforementioned X4.2 event, it dissipated quickly and its analysis is low confidence. Lastly, there was another narrow eruption noted off the NE, first visible in SOHO/LASCO C2 imagery. This event was likely a sympathetic eruption triggered by the X4.2, starting at approximately N15W22 between Regions 4366 and 4367.

There is a slight potential of minor glancing blows from these eruptions early on February 8. Moderate to high solar activity is expected (80%) due to M-class flaring (R1-R2, minor-moderate) for February 5, with a high chance (40%) for X-class flares (R3-strong or greater) due to expected further activity from Region 4366.

Solar wind parameters initially reflected nominal background conditions before showing a clear disturbance beginning February 3. Solar wind speed remained in a slow-wind regime, gradually increasing from about 290 km/s to a peak near 340 km/s.

The solar wind is expected to remain in the current slightly enhanced regime before returning to nominal conditions until mid-day on February 5 when a disturbance is likely, due to the expected arrival of the complex CME ejecta associated with an X8.1 flare from Region 4366.

The 10.7-centimeter flux: February 6, 120; February 7, 125; February 8, 130; February 9, 135; February 10, 140; February 11, 135; February 12, 140.

Predicted sunspot numbers: February 5, 119; February 6, 115; February 7, 125; February 8, 111; February 9, 129; February 10, 105; February 11, 133.

For more information concerning radio propagation, visit the ARRL Technical Information Service, read A Quick Guide to HF Propagation Using Solar Indices, and check out the Propagation Page of Carl Luetzelschwab, K9LA.

For customizable propagation charts, visit the VOACAP Online for Ham Radio website.