:Product: 3-Day Forecast :Issued: 2024 Oct 12 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 8 (NOAA Scale G4). The greatest expected 3 hr Kp for Oct 12-Oct 14 2024 is 5.00 (NOAA Scale G1). NOAA Kp index breakdown Oct 12-Oct 14 2024 Oct 12 Oct 13 Oct 14 00-03UT 4.67 (G1) 3.67 4.00 03-06UT 5.00 (G1) 2.67 3.33 06-09UT 4.33 2.67 2.67 09-12UT 4.00 2.33 2.33 12-15UT 3.33 1.67 2.00 15-18UT 3.00 2.00 2.00 18-21UT 3.00 2.67 2.00 21-00UT 4.00 3.33 2.67 Rationale: The geomagnetic field is likely to reach G1 (Minor) geomagnetic storm levels, with a chance for an isolated G2 (Moderate) storm period, on 12 Oct as effects from a CME that left the sun on 09 Oct continue to wane. B. NOAA Solar Radiation Activity Observation and Forecast Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was above S-scale storm level thresholds. Solar Radiation Storm Forecast for Oct 12-Oct 14 2024 Oct 12 Oct 13 Oct 14 S1 or greater 20% 20% 20% Rationale: The greater than 10 MeV proton flux is expected to remain at background levels with a slight chance for a solar radiation storm event through 14 Oct as AR 3848 approaches the western limb. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Oct 11 2024 1633 UTC. Radio Blackout Forecast for Oct 12-Oct 14 2024 Oct 12 Oct 13 Oct 14 R1-R2 60% 60% 60% R3 or greater 25% 25% 25% Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely, with a chance for R3 (Strong) events through 14 Oct.