####018002515#### FXXX12 KWNP 281231 DAYDIS :Product: Forecast Discussion :Issued: 2024 Apr 28 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 3654 (S07W29, Ehc/beta-gamma-delta) produced two R1 (Minor) events this period, the largest of which was an M3.0 flare at 27/2140 UTC. Region 3654 exhibited moderate development in the intermediate and trailer spots, and developed a delta magnetic configuration. The remaining regions were either stable or in decay. No Earth-directed CMEs were detected in available imagery. .Forecast... Solar activity is expected to be at low levels over 28-30 Apr with a chance for M-class flare (R1-R2/Minor-Moderate) activity. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was at normal to moderate levels and the greater than 10 MeV proton flux was steady at background levels. .Forecast... The greater than 2 MeV electron flux is expected to be at normal to moderate levels over 28-30 Apr. The greater than 10 MeV proton flux is expected to persist at background levels over 28-30 Apr. Solar Wind .24 hr Summary... The solar wind environment was enhanced early in the period due to positive polarity CH HSS influences. Total field strength reached a peak of 13 nT and the Bz component was varied between +11/-10 nT. Solar wind speeds were steady near 400 km/s. The phi angle was in a mostly positive orientation through the period. .Forecast... Enhanced solar wind conditions are likely over 28-30 Apr due to CH HSS influences and possible transient activity associated with multiple CMEs that are expected to pass in close proximity to Earth over the next few days. Geospace .24 hr Summary... The geomagnetic field was at quiet to active levels this period. .Forecast... Geomagnetic field activity is expected to range from quiet to active levels on 28 Apr, and quiet to unsettled levels on 29-30 Apr, due to the anticipated influence of CH HSSs combined with potential transient influence of multiple near-miss CMEs from the past several days. A chance for G1 (Minor) storm periods exists on 28 Apr should these features arrive at Earth and carry periods of significant southward Bz. ####018002178#### FXXX10 KWNP 281231 DAYTDF :Product: 3-Day Forecast :Issued: 2024 Apr 28 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 28-Apr 30 2024 is 4.00 (below NOAA Scale levels). NOAA Kp index breakdown Apr 28-Apr 30 2024 Apr 28 Apr 29 Apr 30 00-03UT 3.67 2.67 2.33 03-06UT 2.00 2.00 2.67 06-09UT 1.33 2.33 2.00 09-12UT 1.33 2.67 2.00 12-15UT 2.67 2.33 1.67 15-18UT 3.00 2.33 1.67 18-21UT 3.67 2.33 2.67 21-00UT 4.00 2.67 1.67 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 28-Apr 30 2024 Apr 28 Apr 29 Apr 30 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 Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Apr 27 2024 2140 UTC. Radio Blackout Forecast for Apr 28-Apr 30 2024 Apr 28 Apr 29 Apr 30 R1-R2 35% 35% 35% R3 or greater 5% 5% 5% Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts over 28-30 Apr.