####018003424#### FXXX12 KWNP 221231 DAYDIS :Product: Forecast Discussion :Issued: 2025 Oct 22 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 remained at low levels. A C3.7 flare originating from beyond the northeastern limb occurred at 21/0649 UTC, which was the largest solar flare of the period. Regions 4252 (S10W85, Cso/beta) and 4263 (N05W12, Bxo) showed signs of slight development as they gained additional, albeit, simple spots. Region 4264 (N07E55, Axx/alpha) was numbered this period, but was otherwise unremarkable. The remaining active regions were stable in comparison. A disappearing solar filament centered near approximately N23E07 was reported by USAF observatories and was observed in SUVI-304 imagery just before 21/0900 UTC. This event was likely at least mostly reabsorbed into the corona as no CME ever became evident in coronagraph imagery. Additional notable activity included a type II radio sweep with an estimated speed of 2,474 km/s and a type IV radio sweep that began at 21/2011 UTC. Significant field line movement, appearing to originate from beyond the northwestern limb, was observed in GOES SUVI imagery beginning at 21/2004 UTC. The subsequent CME was then first seen on LASCO C2 coronagraph imagery at approximately 21/2024 UTC. This event has been analyzed as a far-sided assymetric halo. .Forecast... Solar activity is expected to remain low, with a slight chance for isolated M-class flares (R1-R2/Minor-Moderate), through 24 Oct. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was at normal to moderate levels, and the greater than 10 MeV proton flux became elevated after the far-sided halo CME, but remains below the S1 (10 pfu) threshold. .Forecast... The greater than 2 MeV electron flux is expected to remain at normal to moderate levels through 24 Oct. The greater than 10 MeV proton flux is expected to remain at background levels through 24 Oct, with perhaps a chance for an S1 (Minor) event on 22 Oct due to the aforementioned, large, fast event originating from just beyond the western limb. Solar Wind .24 hr Summary... Solar wind parameters remained mildly enhanced this period due to negative polarity CH HSS influences. Total magnetic field strength reached 7 nT, but the Bz component was mostly near neutral or northward. Solar wind speeds exhibited a decreasing trend from ~560 km/s to under 490 km/s by the periods end. Phi was predominantly positive while undertaking brief excursions into the positive solar sector. .Forecast... Mildly enhanced solar wind conditions and waning negative polarity CH HSS influences are expected to continue through 22 Oct. An ambient-like environment is expected to prevail on 23 Oct and continue into 24 Oct. Geospace .24 hr Summary... The geomagnetic field was quiet to unsettled in response to weak negative polarity CH HSS influences. .Forecast... Quiet to unsettled conditions are expected to continue through 22 Oct as CH HSS influences wane. Mostly quiet conditions are then expected to prevail on 23 Oct and continue on into 24 Oct. ####018002115#### FXXX10 KWNP 221231 DAYTDF :Product: 3-Day Forecast :Issued: 2025 Oct 22 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 Oct 22-Oct 24 2025 is 2.00 (below NOAA Scale levels). NOAA Kp index breakdown Oct 22-Oct 24 2025 Oct 22 Oct 23 Oct 24 00-03UT 1.33 2.00 1.67 03-06UT 1.00 1.67 1.33 06-09UT 0.67 1.33 1.33 09-12UT 1.00 1.00 1.33 12-15UT 1.67 1.00 1.33 15-18UT 0.67 1.33 1.33 18-21UT 1.67 1.67 1.67 21-00UT 2.00 1.67 1.67 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 Oct 22-Oct 24 2025 Oct 22 Oct 23 Oct 24 S1 or greater 25% 10% 1% Rationale: There is an outside chance for an S1 (Minor) event on 22 Oct due to a large, fast event originating from just beyond the western limb. C. NOAA Radio Blackout Activity and Forecast No radio blackouts were observed over the past 24 hours. Radio Blackout Forecast for Oct 22-Oct 24 2025 Oct 22 Oct 23 Oct 24 R1-R2 15% 15% 15% R3 or greater 1% 1% 1% Rationale: There is a slight chance for isolated R1-R2 (Minor-Moderate) radio blackouts through 24 Oct.