####018002178#### FXXX10 KWNP 121231 DAYTDF :Product: 3-Day Forecast :Issued: 2024 Apr 12 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 3 (below NOAA Scale levels). The greatest expected 3 hr Kp for Apr 12-Apr 14 2024 is 4.00 (below NOAA Scale levels). NOAA Kp index breakdown Apr 12-Apr 14 2024 Apr 12 Apr 13 Apr 14 00-03UT 2.33 2.33 1.67 03-06UT 2.67 1.67 1.67 06-09UT 1.67 2.00 4.00 09-12UT 1.67 1.67 3.67 12-15UT 1.33 2.00 3.33 15-18UT 1.33 2.33 3.00 18-21UT 1.67 2.33 2.33 21-00UT 1.67 2.67 3.33 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 12-Apr 14 2024 Apr 12 Apr 13 Apr 14 S1 or greater 1% 1% 1% 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 R2 levels were observed over the past 24 hours. The largest was at Apr 11 2024 1706 UTC. Radio Blackout Forecast for Apr 12-Apr 14 2024 Apr 12 Apr 13 Apr 14 R1-R2 25% 25% 25% R3 or greater 1% 1% 1% Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts over 12-14 Apr. ####018002611#### FXXX12 KWNP 121231 DAYDIS :Product: Forecast Discussion :Issued: 2024 Apr 12 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 due to an M5.4 flare at 11/1706 UTC from a Region just beyond the E limb near S15. Associated with the flare was a Type IV radio sweep and a CME off the SE limb at 11/1712 UTC. Due to its location beyond the limb, no Earth-directed component is expected. Region 3634 (N25E02, Dsi/beta-gamma) produced a C5.5/Sf flare at 12/0327 UTC. Slight growth was observed in this region as well as in Region 3635 (N22E33, Csi/beta-gamma). New Region 3636 (S19E67, Cso/beta) rotated onto the SE limb and was numbered. The CME from a filament eruption near N20E02 that began at 11/0600 UTC was analyzed as a glancing-blow arrival before midday on 14 Apr. A 17 degree long filament, centered near S16W14, began to erupt at about 12/0020 UTC. No apparent CME signature was observed. At this time, no additional Earth-directed CMEs were observed. .Forecast... Solar activity is expected to be low with a chance for M-class flares (R1-R2/Minor-Moderate) on 11-13 Apr. Energetic Particles .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... The greater than 10 MeV proton flux is expected to remain at background levels. The greater than 2 MeV electron flux is expected to continue at normal to moderate levels through 14 Apr. Solar Wind .24 hr Summary... Solar wind parameters were near nominal levels with solar wind speed ranging from about 395-509 km/s. Total field ranged from 3-6 nT while the Bz component was between +6/-5 nT. Phi angle was mostly positive. .Forecast... Nominal solar wind conditions are expected on 12 Apr. Weak HSS disturbances are likely on 13 Apr. By midday on 14 Apr, the glancing-blow arrival of the 11 Apr CME is likely to cause further solar wind enhancements. Geospace .24 hr Summary... The geomagnetic field was quiet to unsettled. .Forecast... Mostly quiet conditions are expected on 12 Apr. Quiet to unsettled levels are likely on 13 Apr with CH HSS onset. Unsettled to active levels are expected on 14 Apr with the combination of a weak HSS and the arrival of the 11 Apr CME.