Subj : 3 Day Space Weather Forecast To : All From : Sean Dennis Date : Tue Jun 17 2025 12:19 am :Product: 3-Day Forecast :Issued: 2025 Jun 17 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 4 (below NOAA Scale levels). The greatest expected 3 hr Kp for Jun 17-Jun 19 2025 is 4.33 (below NOAA Scale levels). NOAA Kp index breakdown Jun 17-Jun 19 2025 Jun 17 Jun 18 Jun 19 00-03UT 3.00 3.33 3.33 03-06UT 3.67 3.00 2.00 06-09UT 2.67 2.00 2.00 09-12UT 2.67 2.33 3.00 12-15UT 2.33 2.67 3.00 15-18UT 1.67 3.33 3.33 18-21UT 0.67 4.00 3.33 21-00UT 1.00 4.33 3.33 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-18 over the past 24 hours, was below S-scale storm level thresholds. Solar Radiation Storm Forecast for Jun 17-Jun 19 2025 Jun 17 Jun 18 Jun 19 S1 or greater 30% 15% 5% Rationale: There is a decreasing chance for S1 (Minor) or greater solar radiation storms over the next three days. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R2 levels were observed over the past 24 hours. The largest was at Jun 16 2025 0938 UTC. Radio Blackout Forecast for Jun 17-Jun 19 2025 Jun 17 Jun 18 Jun 19 R1-R2 75% 75% 70% R3 or greater 30% 30% 30% Rationale: R1-R2 (Minor-Moderate) radio blackouts are expected, with a chance for R3 (Strong) or greater events, over 17-19 Jun. --- MBSE BBS v1.1.1 (Linux-x86_64) * Origin: Outpost BBS * Johnson City, TN (1:18/200) .