####018002258#### FXXX10 KWNP 171231 DAYTDF :Product: 3-Day Forecast :Issued: 2024 Apr 17 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 5 (NOAA Scale G1). The greatest expected 3 hr Kp for Apr 17-Apr 19 2024 is 5.00 (NOAA Scale G1). NOAA Kp index breakdown Apr 17-Apr 19 2024 Apr 17 Apr 18 Apr 19 00-03UT 3.00 3.00 3.00 03-06UT 1.33 3.33 3.00 06-09UT 1.33 5.00 (G1) 2.67 09-12UT 1.67 4.00 2.33 12-15UT 2.00 3.00 2.00 15-18UT 1.33 2.33 2.00 18-21UT 1.67 2.33 2.00 21-00UT 3.00 3.33 2.00 Rationale: G1 (Minor) storm levels are likely on 18 Apr due to an enhancement from CMEs that left the Sun on 14 and 15 Apr. 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 17-Apr 19 2024 Apr 17 Apr 18 Apr 19 S1 or greater 15% 15% 15% Rationale: There is a slight chance for S1 (Minor) or greater solar radiation storms all three days due to collective potential from numerous active regions. 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 16 2024 1802 UTC. Radio Blackout Forecast for Apr 17-Apr 19 2024 Apr 17 Apr 18 Apr 19 R1-R2 65% 65% 65% R3 or greater 15% 15% 15% Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely all three days. There is a slight chance for R3 (Strong) or greater radio blackouts all three days due to the flare potential from several regions. ####018003261#### FXXX12 KWNP 171231 DAYDIS :Product: Forecast Discussion :Issued: 2024 Apr 17 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 due to an M1.1 flare at 16/1802 UTC from newly numbered Region 3645 (S10E31, Cai/beta). Although previously reported as originating from Region 3643, looking at previous imagery of the development of the spot group, it was determined to be a separate region. Region 3645 exhibited slight growth over the period, as well as Regions 3643 (S13E41, Dai/beta) and 3638 (S17E21, Cri/beta). Consolidation was observed in Region 3634 (N27W63, Dki/beta) while Region 3639 (N29E29, Eki/beta-gamma-delta) appeared to be separating. A new region rotated around the NE limb and was numbered as 3646 (N21E66, Hrx/alpha). The rest of the spot groups were either stable or slightly decaying. An approximate 15 degree filament eruption was observed after 16/1900 UTC centered near S45E30. An associated CME was observed off the S limb at 16/2124 UTC. Analysis indicated the potential for a grazing early to midday on 21 Apr. Another filament eruption was observed at 17/0100 UTC in H-alpha imagery. The approximate 20 degree filament structure was centered near N40W00. An associated CME was observed off the NW limb at 17/0506 UTC in SOHO/LASCO C3 imagery. Initial analysis indicated no Earth-directed component. .Forecast... Solar activity is forecast to be moderate, with M-class flares (R1-R2/Minor-Moderate) likely and a slight chance for an X-class flare (R3/Strong) over 17-19 Apr. Energetic Particle .24 hr Summary... The greater than 10 MeV proton flux was at background levels. The greater than 2 MeV electron flux was at normal to moderate levels. .Forecast... There is a slight chance for a greater than 10 MeV proton event (S1/Minor) over 17-19 Apr. The greater than 2 MeV electron flux is expected to continue at normal to moderate levels through 19 Apr. Solar Wind .24 hr Summary... Solar wind parameters continued to be enhanced under CME influence. Although solar wind speed was nominal in the 341-422 km/s range, total field values reached 13 nT with a prolonged period of southward Bz between 16/1205-2231 UTC. .Forecast... Solar wind conditions are expected to trend towards nominal levels mid-day to late on 17 Apr. Early on 18 Apr, additional enhancements are expected due to the anticipated arrival of CMEs that left the Sun on 14 and 15 Apr. Waning CME conditions are likely on 19 Apr. Geospace .24 hr Summary... The geomagnetic field ranged from quiet to G1 (Minor) levels under CME influence. .Forecast... The geomagnetic field is expected to be at quiet to unsettled levels for the rest of the UTC day on 17 Apr. G1 (Minor) geomagnetic storm conditions are likely on 18 Apr due to anticipated arrival of CMEs that left the Sun on 14 and 15 Apr. Quiet to unsettled conditions are likely over 19 Apr as CME influence wanes.