####018003397#### FXXX12 KWNP 031231 DAYDIS :Product: Forecast Discussion :Issued: 2026 Apr 03 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 with M-class (R1-Minor) flare activity observed. Region 4404 (N13W27, Cso/beta) produced an M3.5/2b flare at 02/1815 UTC, the strongest of the period, as the region underwent minor decay. The associated CME, visible off the NW at around 02/1848 UTC in SOHO/LASCO C2 imagery, was modeled and determined to be a miss. Region 4409 (N02E06, Dai/beta-gamma) continued to develop additional spots and area over the past 24 hours, and produced an impulsive M1.3 flare at 03/0756 UTC. The remaining spotted active regions on the visible disk were either mostly stable or in gradual decay. .Forecast... Solar activity is likely to reach moderate (R1-R2/Minor-Moderate) levels, with a chance for X-class (R3-Strong) flares, over 03-05 Apr driven primarily by the flare potential of Regions 4404, 4405, and 4409. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels with a peak flux of 1,590 pfu observed at 03/1000 UTC. The greater than 10 MeV proton flux remained elevated throughout the period following an eruption that occurred on 01 Apr, but remained below S1 (Minor) levels, reaching a peak flux of 6.5 pfu at 03/0405 UTC. .Forecast... The greater than 2 MeV electron flux is expected to reach high levels on 03-05 Apr. There is a chance for the greater than 10 MeV proton flux to exceed S1 (Minor) solar radiation storm levels on 03-05 Apr. Solar Wind .24 hr Summary... Solar wind parameters indicated ongoing negative polarity CH HSS influences. Total magnetic field strength peaked at 14 nT early in the period before decreasing to around 5 nT after 02/1845 UTC. The Bz component briefly reached -11 nT early in the period, then varied between +/-5 nT after 02/1815 UTC. Solar wind speeds increased from around 550 km/s early in the period to a peak of approximately 725 km/s. Phi was predominantly negative. .Forecast... The solar wind environment is expected to remain enhanced through 05 Apr due to ongoing negative polarity CH HSS influences. An additional enhancement is likely late on 03 Apr or early 04 Apr, associated with the anticipated glancing blow arrival of a CME that departed the Sun on 01 Apr. Geospace .24 hr Summary... The geomagnetic field reached G1-G2 (Minor-Moderate) geomagnetic storm levels due to negative polarity CH HSS influences. .Forecast... The geomagnetic field is expected to reach G1 (Minor) storm levels on 03 Apr, with periods of G2 (Moderate) storming likely, driven by ongoing negative polarity CH HSS influences and the possible initial arrival of the 01 Apr CME. G1-G2 (Minor-Moderate) storming is likely on 04 Apr, with a chance for G3 (Strong) storms due to continued -CH HSS influences and the anticipated passage of the 01 Apr CME early in the UTC day. Active conditions are expected on 05 Apr as negative polarity CH HSS influences wane and any remnant CME enhancements subside. ####018002692#### FXXX10 KWNP 031231 DAYTDF :Product: 3-Day Forecast :Issued: 2026 Apr 03 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 6 (NOAA Scale G2). The greatest expected 3 hr Kp for Apr 03-Apr 05 2026 is 6.00 (NOAA Scale G2). NOAA Kp index breakdown Apr 03-Apr 05 2026 Apr 03 Apr 04 Apr 05 00-03UT 4.00 5.67 (G2) 3.67 03-06UT 3.67 6.00 (G2) 4.67 (G1) 06-09UT 5.00 (G1) 5.67 (G2) 3.67 09-12UT 4.00 4.67 (G1) 3.00 12-15UT 4.67 (G1) 4.67 (G1) 2.67 15-18UT 3.67 4.00 2.67 18-21UT 3.67 3.67 1.67 21-00UT 5.67 (G2) 3.67 2.67 Rationale: The geomagnetic field is expected to reach G1 (Minor) storm levels on 03 Apr, with periods of G2 (Moderate) storming likely, driven by ongoing negative polarity CH HSS influences and the possible initial arrival of the 01 Apr CME. G1-G2 (Minor-Moderate) storming is likely on 04 Apr, with a chance for G3 (Strong) storms due to continued -CH HSS influences and the anticipated passage of the 01 Apr CME early in the UTC day. Active conditions are expected on 05 Apr as negative polarity CH HSS influences wane and any remnant CME enhancements subside. 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 03-Apr 05 2026 Apr 03 Apr 04 Apr 05 S1 or greater 50% 50% 25% Rationale: There is a chance for the greater than 10 MeV proton flux to exceed S1 (Minor) solar radiation storm levels on 03-05 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 02 2026 1815 UTC. Radio Blackout Forecast for Apr 03-Apr 05 2026 Apr 03 Apr 04 Apr 05 R1-R2 55% 55% 55% R3 or greater 25% 25% 25% Rationale: Solar activity is likely to reach moderate (R1-R2/Minor-Moderate) levels, with a chance for X-class (R3-Strong) flares, over 03-05 Apr driven primarily by the flare potential of Regions 4404, 4405, and 4409.