FXXX10 KWNP 120031 DAYTDF :Product: 3-Day Forecast :Issued: 2025 Dec 12 0030 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center # Product description and SWPC contact on the Web # http://www.swpc.noaa.gov/wwire.html # # 3-Day Forecast # A. NOAA Geomagnetic Activity Observation and Forecast The greatest observed 3 hr Kp over the past 24 hours was 6 (NOAA Scale G2). The greatest expected 3 hr Kp for Dec 12-Dec 14 2025 is 4.67 (NOAA Scale G1). NOAA Kp index breakdown Dec 12-Dec 14 2025 Dec 12 Dec 13 Dec 14 00-03UT 4.00 4.33 3.67 03-06UT 4.67 (G1) 3.67 3.00 06-09UT 4.00 2.33 2.67 09-12UT 3.67 1.67 2.67 12-15UT 3.33 2.00 2.67 15-18UT 3.00 2.67 2.00 18-21UT 3.33 3.33 2.00 21-00UT 3.67 3.67 2.67 Rationale: G1 (Minor) storming is likely early on 12 Dec as weak enhancements in the solar wind environment persist. 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 Dec 12-Dec 14 2025 Dec 12 Dec 13 Dec 14 S1 or greater 10% 5% 1% Rationale: There is a slight chance for an S1 (Minor) radiation storming event on 12 Dec as the complex regions in the western hemisphere move beyond the limb. C. NOAA Radio Blackout Activity and Forecast No radio blackouts were observed over the past 24 hours. Radio Blackout Forecast for Dec 12-Dec 14 2025 Dec 12 Dec 13 Dec 14 R1-R2 65% 60% 55% R3 or greater 10% 5% 5% Rationale: Chances for R1-R2 (Minor-Moderate) radio blackouts decrease over 12-14 Dec as major flare producing regions move beyond the west limb.