####018002394#### FXXX12 KWNP 251231 DAYDIS :Product: Forecast Discussion :Issued: 2025 Sep 25 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 M1.6 (R1-Minor) flare from Region 4224 (S13W58, Cso/beta). The region experienced slight growth but remains relatively simple. Regions 4229 (S03W55, Dai/beta-gamma) and 4217 (S17W68, Cao/beta-gamma) which sit above and below Region 4224 - both experienced growth during the period and were responsible for multiple C-class flares. Region 4226 (S11E11, Dsi/beta-gamma) was also responsible for a few C-class flares and showed growth in both its leader and trailer spots. A new, simple spot group trailing AR 4229 was observed, but remains unnumbered at this time as we await corroborating observatory reports. No Earth-directed CMEs observed in available coronagraph imagery. .Forecast... Solar activity is expected to be low, with a chance for isolated M-class flare activity (R1-R2/Minor-Moderate) through 27 Sep. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux remained at moderate levels. The greater than 10 MeV proton flux was at background. .Forecast... The greater than 2 MeV electron flux is expected to continue around moderate levels as CH HSS influences wane. The greater than 10 MeV proton flux is expected to continue at background levels. Solar Wind .24 hr Summary... Weakening negative polarity CH HSS can be seen in the solar wind parameters. Total field remained around 5 nT with a variable Bz component between +/-5 nT. Solar wind speeds were on a gradual decline from 550 to 480 km/s. The phi angle was negative. .Forecast... Mostly nominal conditions are expected through 26 Sep. Relatively weak enhancements are anticipated by late on 27 Sep as negative polarity CH HSS influences begin. Geospace .24 hr Summary... The geomagnetic field has been at quiet to unsettled levels. .Forecast... Primarily quiet levels are expected through 26 Sep. Quiet to unsettled conditions are expected on 27 Sep as negative polarity CH HSS effects begin. ####018002183#### FXXX10 KWNP 251231 DAYTDF :Product: 3-Day Forecast :Issued: 2025 Sep 25 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 Sep 25-Sep 27 2025 is 3.00 (below NOAA Scale levels). NOAA Kp index breakdown Sep 25-Sep 27 2025 Sep 25 Sep 26 Sep 27 00-03UT 1.33 1.67 2.33 03-06UT 1.00 1.33 2.00 06-09UT 2.00 1.33 2.00 09-12UT 1.00 1.33 1.67 12-15UT 1.00 1.33 2.00 15-18UT 1.33 1.33 2.00 18-21UT 1.67 1.67 2.00 21-00UT 1.67 1.67 3.00 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 Sep 25-Sep 27 2025 Sep 25 Sep 26 Sep 27 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 R1 levels were observed over the past 24 hours. The largest was at Sep 24 2025 1913 UTC. Radio Blackout Forecast for Sep 25-Sep 27 2025 Sep 25 Sep 26 Sep 27 R1-R2 35% 35% 35% R3 or greater 1% 1% 1% Rationale: There is a chance for R1 (Minor) to R2 (Moderate) radio blackouts through 27 Sep.