:Product: 3-Day Forecast :Issued: 2022 Aug 16 1230 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 Aug 16-Aug 18 2022 is 6 (NOAA Scale G2). NOAA Kp index breakdown Aug 16-Aug 18 2022 Aug 16 Aug 17 Aug 18 00-03UT 1 2 4 03-06UT 2 2 5 (G1) 06-09UT 1 3 6 (G2) 09-12UT 2 3 5 (G1) 12-15UT 1 4 5 (G1) 15-18UT 1 4 4 18-21UT 2 5 (G1) 4 21-00UT 2 5 (G1) 4 Rationale: G1 (Minor) geomagnetic storms are likely on 17 Aug due to a combination of CH HSS influences and CME arrival. G2 (Moderate) geomagnetic storms are likely on 18 Aug due to the anticipated subsequent CMEs. B. NOAA Solar Radiation Activity Observation and Forecast Solar radiation, as observed by NOAA GOES-16 over the past 24 hours, was below S-scale storm level thresholds. Solar Radiation Storm Forecast for Aug 16-Aug 18 2022 Aug 16 Aug 17 Aug 18 S1 or greater 10% 10% 10% Rationale: There is a slight chance for S1 (Minor) or greater solar radiation storms on 16-18 Aug mainly due to the potential from Region 3078. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R2 levels were observed over the past 24 hours. The largest was a M5.0 on Aug 16 2022 0758 UTC. Radio Blackout Forecast for Aug 16-Aug 18 2022 Aug 16 Aug 17 Aug 18 R1-R2 30% 30% 30% R3 or greater 10% 10% 10% Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts on 16-18 Aug, and a slight chance for R3 (Strong) radio blackouts due to the flare potential of Region 3078.