####018002217#### FXXX10 KWNP 231231 DAYTDF :Product: 3-Day Forecast :Issued: 2024 Apr 23 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 2 (below NOAA Scale levels). The greatest expected 3 hr Kp for Apr 23-Apr 25 2024 is 4.33 (below NOAA Scale levels). NOAA Kp index breakdown Apr 23-Apr 25 2024 Apr 23 Apr 24 Apr 25 00-03UT 2.00 3.00 3.00 03-06UT 1.00 2.67 2.67 06-09UT 2.33 2.67 3.67 09-12UT 2.00 2.00 4.33 12-15UT 2.67 2.00 3.67 15-18UT 2.67 1.67 3.33 18-21UT 2.67 1.67 2.67 21-00UT 3.00 2.67 4.00 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 23-Apr 25 2024 Apr 23 Apr 24 Apr 25 S1 or greater 20% 20% 20% Rationale: There is a slight chance for S1 (Minor) solar radiation storms over 23-25 Apr due to the flare potential of several regions on the visible disk. 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 23 2024 0319 UTC. Radio Blackout Forecast for Apr 23-Apr 25 2024 Apr 23 Apr 24 Apr 25 R1-R2 75% 75% 75% R3 or greater 20% 20% 20% Rationale: R1-R2 (Minor-Moderate) radio blackouts are expected, with a slight chance for R3 (Strong) or greater events, over 23-25 Apr. ####018003213#### FXXX12 KWNP 231231 DAYDIS :Product: Forecast Discussion :Issued: 2024 Apr 23 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 high levels this period with a total of eight M-class flares (R1/Minor) observed from a variety of sources; the largest of which was an M3.6 flare at 23/0319 UTC from Region 3654 (S08E39, Dai/beta). Region 3638 (S18W57, Bxo/beta) produced an M1.5 flare at 22/2116 UTC and continued a trend of decay. Region 3645 (S08W54, Dac/beta-gamma) produced two M1 flares at 22/1335 UTC and 22/1455 UTC, and exhibited some growth in the leader spot area. Region 3646 (N21W06, Dai/beta-gamma) produced an M1.6 flare at 22/1519 UTC and increased in size, spot count, and became more magnetically complex. In addition to the M3.6 flare detailed above, Region 3654 produced an M3.0 flare at 23/0821 UTC and underwent moderate development. Region 3656 (S12E53, Bxo/beta) produced an M2.8 flare at 22/1550 UTC and an M1.0 flare at 22/1630 UTC, but was in decay. Other activity included a filament eruption near S10W02 that began at around 23/0330 UTC, though no clearly-associated CME was visible in LASCO imagery. No Earth-directed CMEs were detected, however, multiple narrow, southward CMEs associated with activity emanating from the active region cluster in the SW over the past several days are likely to make close approaches to Earth. .Forecast... Solar activity is expected to be at moderate to high levels over 23-25 Apr, with M-class flares (R1-R2/Minor-Moderate) expected, and a slight chance for an X-class flare (R3/Strong). Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was normal to moderate and the greater than 10 MeV proton flux was at background levels. .Forecast... There is a slight chance for the greater than 10 MeV proton flux to reach S1 (Minor) levels over 23-25 Apr due to the flare potential and location of several active regions on the visible disk. The greater than 2 MeV electron flux is expected to continue at normal to moderate levels throughout the forecast period. Solar Wind .24 hr Summary... Ambient solar wind conditions prevailed throughout the period. Wind speeds decreased from 400-450 km/s early in the day to between 350-400 km/s. Total field strength was steady near 5 nT and Bz varied +/-5 nT. The phi angle was negative. .Forecast... Enhanced solar wind conditions are expected to prevail over 23-25 Apr due to CH HSS influences and possible CME activity. Geospace .24 hr Summary... The geomagnetic field was quiet. .Forecast... Geomagnetic field activity is expected to reach unsettled and active levels on 23 Apr, and quiet and unsettled levels on 24 Apr, due to negative polarity CH HSS influences. Unsettled and active levels are expected again on 25 Apr due to possible CME activity and the onset of positive polarity CH HSS influences.