Subj : 3 Day Space Weather Forecast To : All From : Sean Dennis Date : Thu Aug 13 2026 12:19 am :Product: 3-Day Forecast :Issued: 2026 Aug 13 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 3 (below NOAA Scale levels). The greatest expected 3 hr Kp for Aug 13-Aug 15 2026 is 4.00 (below NOAA Scale levels). NOAA Kp index breakdown Aug 13-Aug 15 2026 Aug 13 Aug 14 Aug 15 00-03UT 2.00 3.67 3.67 03-06UT 1.67 3.33 3.33 06-09UT 1.33 3.00 3.00 09-12UT 1.00 2.67 3.00 12-15UT 1.33 3.00 2.33 15-18UT 1.67 3.33 2.67 18-21UT 1.67 3.33 3.00 21-00UT 3.00 4.00 3.00 Rationale: No G1 (Minor) or greater geomagnetic storms are expected. Unsettled to active levels are expected on 14-15 Aug due to CH HSS effects. 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 Aug 13-Aug 15 2026 Aug 13 Aug 14 Aug 15 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 No radio blackouts were observed over the past 24 hours. Radio Blackout Forecast for Aug 13-Aug 15 2026 Aug 13 Aug 14 Aug 15 R1-R2 10% 15% 15% R3 or greater 1% 1% 1% Rationale: Solar activity is expected to be low to very low 13-15 Aug, though there is an increasing but slight chance for M-class (R1-R2/Minor-Moderate) flares, primarily driven by the development observed in Regions 4503 and 4507. --- MBSE BBS v1.1.7.2 (Linux-x86_64) * Origin: Outpost BBS * Johnson City, TN (1:18/200) .