FXXX10 KWNP 050031 DAYTDF :Product: 3-Day Forecast :Issued: 2026 May 05 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 May 05-May 07 2026 is 5.67 (NOAA Scale G2). NOAA Kp index breakdown May 05-May 07 2026 May 05 May 06 May 07 00-03UT 5.33 (G1) 2.67 3.33 03-06UT 5.67 (G2) 2.33 3.67 06-09UT 5.00 (G1) 2.00 3.00 09-12UT 4.00 1.33 2.33 12-15UT 3.00 1.67 2.33 15-18UT 2.33 2.33 3.33 18-21UT 2.00 2.00 3.33 21-00UT 2.67 2.67 3.67 Rationale: Isolated G1-G2 (Minor-Moderate) storming periods are possible early on 05 May as CME/CH HSS effects persist. B. NOAA Solar Radiation Activity Observation and Forecast Solar radiation, as observed by NOAA GOES-19 over the past 24 hours, was below S-scale storm level thresholds. Solar Radiation Storm Forecast for May 05-May 07 2026 May 05 May 06 May 07 S1 or greater 5% 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 Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at May 04 2026 0133 UTC. Radio Blackout Forecast for May 05-May 07 2026 May 05 May 06 May 07 R1-R2 30% 30% 30% R3 or greater 5% 5% 5% Rationale: There is a chance for isolated R1-R2 (Minor-Moderate) radio blackouts on 05-07 May, primarily due to the flare potential of Region 4429.