Subj : 3 Day Space Weather Forecast To : All From : Sean Dennis Date : Mon May 12 2025 00:19:01 :Product: 3-Day Forecast :Issued: 2025 May 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 5 (NOAA Scale G1). The greatest expected 3 hr Kp for May 12-May 14 2025 is 4.67 (NOAA Scale G1). NOAA Kp index breakdown May 12-May 14 2025 May 12 May 13 May 14 00-03UT 4.00 2.67 2.33 03-06UT 4.67 (G1) 3.67 2.67 06-09UT 3.33 2.67 2.33 09-12UT 3.00 2.67 2.33 12-15UT 2.67 1.67 2.67 15-18UT 3.67 1.67 2.33 18-21UT 2.67 3.00 2.33 21-00UT 2.67 2.67 2.00 Rationale: An isolated period of G1 (Minor) conditions are expected on 12 May as negative polarity CH HSS influences linger yet diminish. 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 May 12-May 14 2025 May 12 May 13 May 14 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 Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at May 12 2025 0001 UTC. Radio Blackout Forecast for May 12-May 14 2025 May 12 May 13 May 14 R1-R2 1% 1% 1% R3 or greater 1% 1% 1% Rationale: No R1 (Minor) or greater radio blackouts are expected. No significant active region flare activity is forecast. --- MBSE BBS v1.1.1 (Linux-x86_64) * Origin: Outpost BBS * Johnson City, TN (1:18/200) .