####018002617#### FXXX12 KWNP 261231 DAYDIS :Product: Forecast Discussion :Issued: 2024 Mar 26 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. Region 3615 (S13W35, Fkc/beta-gamma-delta) began to exhibit decay and separation in and in between its intermediate and trailing spots. AR 3615 continued to be responsible for the majority of the flare activity producing a M1.8 flare at 26/0036 UTC, which was the largest of the period. The remaining active regions were stable and relatively quiet in comparison. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to continue at moderate (R1-R2/Minor-Moderate) levels, with a chance for an X-class flares (R3/Strong), over 26-28 Mar due primarily to the flare potential of Region 3615. Energetic Particle .24 hr Summary... The greater than 10 MeV proton flux peaked at 16 pfu at 25/1235 UTC, but has since decreased to below the SWPC warning threshold of 10 pfu. The greater than 2 MeV electron flux was at normal to moderate levels. .Forecast... A chance for S1 (Minor) solar radiation storms will persist through 28 Mar primarily due to the potential and location of AR 3615. The greater than 2 MeV electron flux is expected to be at normal to moderate levels through 27 Mar with a chance to reach high levels beginning on 28 Mar. Solar Wind .24 hr Summary... Solar wind parameters, as measured by the ACE spacecraft, reflected the influence of a coronal mass ejection (CME) that left the Sun on 23 Mar. Total field gradually weakened over the period decreasing from 7 to 2 nT, and the Bz component was mostly near neutral or northward. Solar wind speeds decreased from ~775 km/s to lows near 550 km/s before stabilizing around 640 km/s by the end of the period. Phi was predominantly in a positive solar sector. .Forecast... Enhancements from the passing CME are likely to continue to weaken over 26 Mar and ambient solar wind conditions are expected to return on 27-28 Mar. Geospace .24 hr Summary... The geomagnetic field was quiet to unsettled with an early, isolated active period. .Forecast... Unsettled to G1 (Minor) levels are likely on 26 Mar as CME influence diminishes. Quiet to unsettled levels are expected to return on 27-28 Mar. ####018002176#### FXXX10 KWNP 261231 DAYTDF :Product: 3-Day Forecast :Issued: 2024 Mar 26 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 Mar 26-Mar 28 2024 is 4.67 (NOAA Scale G1). NOAA Kp index breakdown Mar 26-Mar 28 2024 Mar 26 Mar 27 Mar 28 00-03UT 3.33 2.33 1.67 03-06UT 2.67 2.67 1.67 06-09UT 1.00 2.33 1.67 09-12UT 3.00 1.67 1.33 12-15UT 3.00 1.33 1.33 15-18UT 3.33 2.00 1.33 18-21UT 4.00 2.00 1.33 21-00UT 4.67 (G1) 2.33 1.33 Rationale: G1 (Minor) geomagnetic storming is likely on 26 Mar due to lingering CME effects. B. NOAA Solar Radiation Activity Observation and Forecast Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was above S-scale storm level thresholds. Solar Radiation Storm Forecast for Mar 26-Mar 28 2024 Mar 26 Mar 27 Mar 28 S1 or greater 30% 30% 30% Rationale: A chance for S1 (Minor) solar radiation storms will persist though 28 Mar primarily due to AR 3615s location and flare potential. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Mar 26 2024 0036 UTC. Radio Blackout Forecast for Mar 26-Mar 28 2024 Mar 26 Mar 27 Mar 28 R1-R2 75% 75% 75% R3 or greater 25% 25% 25% Rationale: R1-R2 (Minor-Moderate) radio blackouts are expected on 26-28 Mar with a chance for an isolated R3 (Strong) event due to the flare potential from Region 3615.