:Product: 3-Day Forecast :Issued: 2023 Jun 04 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 Jun 04-Jun 06 2023 is 3.67 (below NOAA Scale levels). NOAA Kp index breakdown Jun 04-Jun 06 2023 Jun 04 Jun 05 Jun 06 00-03UT 3.67 3.33 2.67 03-06UT 3.67 3.33 2.67 06-09UT 3.33 3.00 2.33 09-12UT 3.00 3.00 2.00 12-15UT 2.33 2.00 1.67 15-18UT 2.67 1.67 1.33 18-21UT 2.00 2.00 1.33 21-00UT 2.67 2.67 1.33 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-16 over the past 24 hours, was below S-scale storm level thresholds. Solar Radiation Storm Forecast for Jun 04-Jun 06 2023 Jun 04 Jun 05 Jun 06 S1 or greater 10% 10% 10% Rationale: There is a slight chance for S1 (Minor) or greater solar radiation storms on Jun 04-06. C. NOAA Radio Blackout Activity and Forecast No radio blackouts were observed over the past 24 hours. Radio Blackout Forecast for Jun 04-Jun 06 2023 Jun 04 Jun 05 Jun 06 R1-R2 35% 30% 30% R3 or greater 10% 10% 10% Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts, with a slight chance for R3 or greater radio blackouts, on Jun 04-06, from Regions 3319 and 3323.