####018002099#### FXXX10 KWNP 291231 DAYTDF :Product: 3-Day Forecast :Issued: 2025 Oct 29 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 Oct 29-Oct 31 2025 is 4.67 (NOAA Scale G1). NOAA Kp index breakdown Oct 29-Oct 31 2025 Oct 29 Oct 30 Oct 31 00-03UT 3.00 4.67 (G1) 3.67 03-06UT 3.00 4.00 3.67 06-09UT 3.33 4.00 3.33 09-12UT 3.00 3.67 3.00 12-15UT 3.00 3.67 3.00 15-18UT 4.00 4.00 3.33 18-21UT 4.67 (G1) 3.33 3.00 21-00UT 4.00 3.33 3.00 Rationale: G1 (Minor) geomagnetic storming is likely on 29-30 Oct due to persistent CH HSS effects. 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 Oct 29-Oct 31 2025 Oct 29 Oct 30 Oct 31 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 No radio blackouts were observed over the past 24 hours. Radio Blackout Forecast for Oct 29-Oct 31 2025 Oct 29 Oct 30 Oct 31 R1-R2 5% 5% 5% R3 or greater 1% 1% 1% Rationale: No R1 (Minor) or greater radio blackouts are expected. No significant active region flare activity is forecast. ####018002343#### FXXX12 KWNP 291231 DAYDIS :Product: Forecast Discussion :Issued: 2025 Oct 29 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 low levels due to an isolated C1.6 flare at 28/1626 UTC from Region 4267 (N04W05, Dso/beta). Slight growth was observed in Regions 4267 and 4266 (N17W31, Cro/beta). The rest of the spotted regions were either stable or in decay. Other activity included a CME off the NE limb at 29/0012 UTC. An associated Type II radio sweep (1,357 km/s) was reported with the CME, however SUVI 195 imagery revealed the CME to have originated on the far side. Also, an approximate 12 degree filament eruption, centered near N27W24 was observed lifting off beginning at 29/0058 UTC. CME analysis will be conducted as imagery becomes available. .Forecast... Solar activity is expected to remain very low to low through 31 Oct. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was at normal to moderate levels. The greater than 10 MeV proton flux was at background levels. .Forecast... The greater than 2 MeV electron flux is expected to reach high levels on 30-31 Oct in response to the positive coronal hole (CH) high speed stream (HSS) influence. The greater than 10 MeV proton flux is expected to remain at background levels through 31 Oct. Solar Wind .24 hr Summary... Solar wind parameters continued under CH HSS influence, albeit to a lesser extent than recurrent trends. Solar wind speed increased from approximately 400 km/s to near 480 km/s. Total field continued to be enhanced around 9-13 nT with the Bz component between +12/-11 nT. Phi angle was predominantly positive. .Forecast... Solar wind parameters are expected to continue to reflect positive CH/HSS influences through 31 Oct. Geospace .24 hr Summary... The geomagnetic field has been unsettled to active due to CH HSS activity. .Forecast... Unsettled to active conditions are expected through 31 Oct, with G1 (Minor) storming likely on 29-30 Oct, due to persistent CH HSS effects.