####018002302#### FXXX10 KWNP 051231 DAYTDF :Product: 3-Day Forecast :Issued: 2025 Nov 05 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 Nov 05-Nov 07 2025 is 5.00 (NOAA Scale G1). NOAA Kp index breakdown Nov 05-Nov 07 2025 Nov 05 Nov 06 Nov 07 00-03UT 4.00 2.33 5.00 (G1) 03-06UT 3.33 3.00 4.67 (G1) 06-09UT 4.33 3.00 4.00 09-12UT 2.33 3.00 3.33 12-15UT 3.00 3.00 3.00 15-18UT 2.33 3.33 2.67 18-21UT 2.67 3.33 2.67 21-00UT 2.67 4.67 (G1) 3.67 Rationale: G1 (Minor) with a slight chance for G2 (Moderate) geomagnetic storm conditions are likely on 06-07 Nov due to CH HSS activity coupled with a possible glancing blow from the 03-04 Nov CMEs. 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 Nov 05-Nov 07 2025 Nov 05 Nov 06 Nov 07 S1 or greater 25% 25% 25% Rationale: There is a chance for the greater than 10 MeV proton flux reaching the S1 (Minor) threshold on 05-07 Nov due to the flare potential of Region 4274. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R3 levels were observed over the past 24 hours. The largest was at Nov 04 2025 1734 UTC. Radio Blackout Forecast for Nov 05-Nov 07 2025 Nov 05 Nov 06 Nov 07 R1-R2 70% 70% 70% R3 or greater 25% 25% 25% Rationale: Probabilities have increased to 70% for R1-R2 (Minor-Moderate) and 25% for R3 (Strong) due to the continued activity and complex structure of Region 4274. ####018003811#### FXXX12 KWNP 051231 DAYDIS :Product: Forecast Discussion :Issued: 2025 Nov 05 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 a pair of X-class flares. The first was an X1.8/1b at 04/1734 UTC from Region 4274 (N24E47, Ekc/beta-gamma-delta). Associated with the flare were Type IV radio sweeps, 160 sfu Tenflare, and a partial halo CME directed mostly off the NE limb at 04/1736 UTC in coronagraph imagery. Although the majority of the ejecta is expected to pass behind Earth, there is the possibility of a shock enhancement late on 06 Nov to early on 07 Nov. Region 4274 continued to be in a growth phase, however the intermediate spots appeared to begin to separate from the larger trailing spots. An X1.1 flare was also observed at 04/2201 UTC from a Region just beyond the E limb near S15. Associated with this flare were a Type IV radio sweep and a non-Earth directed CME observed off the SE limb at 04/2212 UTC. An M1.7/1f flare occurred at 04/2244 UTC from Region 4272 (N22E30, Hsx/alpha) with an associated non-Earth directed CME off the NE limb beginning at 04/2312 UTC. An M7.4 flare occurred at 05/1119 UTC, also from Region 4274. Analysis of potential ejecta is pending further observations. .Forecast... Probabilities have increased to 70% for R1-R2 (Minor-Moderate) and 25% for R3 (Strong) due to the continued activity and complex structure of Region 4274. Energetic Particle .24 hr Summary... The greater the 2 MeV electron flux continues to surpass the 1000 pfu threshold during the diurnal maxima but the overall trend is going down. This is due to Earth moving out of the geoeffective position with the coronal hole (CH) high speed stream (HSS) originating in the SW. The greater than 10 MeV proton flux became enhanced, but well below the S1 (Minor) threshold, after 05/0035 UTC following X-flare activity. .Forecast... Electrons will continue to come down through 06 Nov as CH HSS influences wane. Expect a rise again 07 Nov as the HSS associated with the negative polarity CH crossing the central meridian becomes geoeffective. There is a chance for the greater than 10 MeV proton flux reaching the S1 (Minor) threshold on 05-07 Nov due to the flare potential of Region 4274. Solar Wind .24 hr Summary... Solar wind parameters were near nominal levels. Solar wind speed ranged from 341-447 km/s. Total field ranged from 3-7 nT. There was a prolonged period of southward Bz reaching -6 nT beginning at 04/2044. Phi angle was positive. .Forecast... Solar wind parameters are likely to trend towards nominal levels 05-06 Nov. Parameters are expected to become enhanced with the arrival of the next CH HSS 06-07 Nov. There are also now three CMEs - two that left the disk 03 Nov and one on 04 Nov, all from Region 4274 - that are projected to pass behind Earth with tail ends of their magnetic clouds interacting with the CH HSS. The combination of CME/HSS will produce enhanced solar wind parameters 06-07 Nov. Geospace .24 hr Summary... The geomagnetic field was at quiet to active levels due to a prolonged period of southward Bz. .Forecast... The field will remain at quiet to active levels on 05 Nov. Late 06 Nov, into 07 Nov, the CH HSS coupled with potential arrivals of the aforementioned CMEs will likely produce G1 (Minor) geomagnetic storming levels with a slight chance for the G2 (Moderate) levels. Watches have been issued during these times.