:Product: 04211230three_day_forecast.txt :Issued: 2014 Apr 21 1230 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 5 (NOAA Scale G1). The greatest expected 3 hr Kp for Apr 21-Apr 23 2014 is 4 (below NOAA Scale levels). NOAA Kp index breakdown Apr 21-Apr 23 2014 Apr 21 Apr 22 Apr 23 00-03UT 4 4 3 03-06UT 4 3 2 06-09UT 3 2 2 09-12UT 4 2 2 12-15UT 2 2 2 15-18UT 2 2 2 18-21UT 3 2 2 21-00UT 3 3 2 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-13 over the past 24 hours, was below S-scale storm level thresholds. Solar Radiation Storm Forecast for Apr 21-Apr 23 2014 Apr 21 Apr 22 Apr 23 S1 or greater 5% 5% 5% 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 Apr 21-Apr 23 2014 Apr 21 Apr 22 Apr 23 R1-R2 55% 50% 50% R3 or greater 10% 5% 5% Rationale: R1-R2 (Minor-Moderate) radio blackout conditions are likely with a chance for R3 or greater on 21 Apr due to a continued threat of flare activity from significant active regions. As the significant active regions begin to rotate off the west limb on 22-23 Apr, only a chance for R1-R2 conditions exists.