####018002254#### FXXX10 KWNP 051231 DAYTDF :Product: 3-Day Forecast :Issued: 2026 Apr 05 1230 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 4 (below NOAA Scale levels). The greatest expected 3 hr Kp for Apr 05-Apr 07 2026 is 3.67 (below NOAA Scale levels). NOAA Kp index breakdown Apr 05-Apr 07 2026 Apr 05 Apr 06 Apr 07 00-03UT 3.67 2.67 2.67 03-06UT 3.00 3.00 2.67 06-09UT 3.00 2.67 2.67 09-12UT 3.00 2.67 2.00 12-15UT 2.00 2.00 0.67 15-18UT 1.67 1.67 0.67 18-21UT 1.67 1.67 1.67 21-00UT 2.00 2.67 2.67 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 Apr 05-Apr 07 2026 Apr 05 Apr 06 Apr 07 S1 or greater 20% 20% 20% Rationale: There is a slight chance for the greater than 10 MeV proton flux to exceed S1 (Minor) solar radiation storm levels over 05-07 Apr. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Apr 04 2026 2304 UTC. Radio Blackout Forecast for Apr 05-Apr 07 2026 Apr 05 Apr 06 Apr 07 R1-R2 55% 55% 55% R3 or greater 20% 20% 20% Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely, with a slight chance for X-class R3 (Strong) events, over 05-07 Apr, driven primarily by the flare potential of Region 4409. ####018002597#### FXXX12 KWNP 051231 DAYDIS :Product: Forecast Discussion :Issued: 2026 Apr 05 1230 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 # # Forecast Discussion # Solar Activity .24 hr Summary... Solar activity reached moderate levels. Region 4409 (N02W21, Eai/beta-gamma) produced an M1.2/1f flare (R1-Minor) at 04/1211 UTC and an M1.0 flare (R1) at 04/2304 UTC, in addition to numerous C-class flares throughout the period. The region exhibited minor decay and separation among its leader spots. New Region 4412 (N08E15, Bxo/beta) was numbered and produced a few low-level C-flares late in the period. The remaining spotted regions on the visible disk were either mostly stable or in gradual decay. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is likely to reach moderate (R1-R2/Minor-Moderate) levels, with a slight chance for X-class (R3/Strong) flares, over 05-07 Apr, driven primarily by the flare potential of Region 4409. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels with a peak flux of 2,420 pfu at 04/1600 UTC. The greater than 10 MeV proton flux continued a gradual decline towards background levels throughout the period. .Forecast... The greater than 2 MeV electron flux is expected to reach high levels on 05-07 Apr. There is a slight chance for the greater than 10 MeV proton flux to exceed S1 (Minor) solar radiation storm levels over 05-07 Apr. Solar Wind .24 hr Summary... Solar wind parameters suggested the return of influence from a negative polarity CH HSS. Total magnetic field strength was steady at around 5 nT and no significant periods of southward Bz were observed. Wind speeds gradually declined from ~650 km/s to between 550-600 km/s by the end of the period. Phi angle was predominantly oriented in the negative solar sector. .Forecast... The solar wind environment is expected to remain enhanced through 07 Apr due to waning negative polarity CH HSS influence. Geospace .24 hr Summary... The geomagnetic field reached active levels during the period under negative polarity CH HSS influences. .Forecast... The geomagnetic field is expected to reach active levels early on 05 Apr, with quiet to unsettled levels expected on 06-07 Apr, as negative polarity CH HSS influences gradually wane.