:Product: 3-Day Forecast :Issued: 2026 Oct 26 0030 UTC # Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center # A. NOAA Geomagnetic Activity Observation and Forecast The greatest observed 3 hr Kp over the past 24 hours was 2 (below NOAA Scale levels). The greatest expected 3 hr Kp for Oct 26-Oct 28 2026 is 3.00 (below NOAA Scale levels). NOAA Kp index breakdown Oct 26-Oct 28 2026 Oct 26 Oct 27 Oct 28 00-03UT 1.67 1.67 1.33 03-06UT 1.33 1.33 1.33 06-09UT 1.33 1.33 1.67 09-12UT 1.33 1.33 1.33 12-15UT 1.33 1.33 1.33 15-18UT 1.33 1.33 1.33 18-21UT 1.67 1.67 1.67 21-00UT 1.67 1.67 1.67 Rationale: No G1 (Minor) or greater geomagnetic storms are expected. No significant transient or recurrent solar wind features are forecast. B. NOAA Solar Radiation Activity Observation and Forecast Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was below S-scale storm level thresholds. Solar Radiation Storm Forecast for Oct 26-Oct 28 2026 Oct 26 Oct 27 Oct 28 S1 or greater 1% 1% 1% Rationale: No S1 (Minor) or greater solar radiation storms are expected. No significant active region activity favorable for radiation storm production is forecast. C. NOAA Radio Blackout Activity and Forecast No radio blackouts were observed over the past 24 hours. Radio Blackout Forecast for Oct 26-Oct 28 2026 Oct 26 Oct 27 Oct 28 R1-R2 10% 1% 1% R3 or greater 1% 1% 1% Rationale: There is a slight chance for an isolated R1-R2 (Minor-Moderate) radio blackout on 26 Oct. No R1 (Minor) or greater radio blackouts are expected on 27-28 Oct.