####018002234#### FXXX10 KWNP 121231 DAYTDF :Product: 3-Day Forecast :Issued: 2024 May 12 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 9 (NOAA Scale G5). The greatest expected 3 hr Kp for May 12-May 14 2024 is 7.67 (NOAA Scale G4). NOAA Kp index breakdown May 12-May 14 2024 May 12 May 13 May 14 00-03UT 6.67 (G3) 5.00 (G1) 4.67 (G1) 03-06UT 7.00 (G3) 6.67 (G3) 4.33 06-09UT 3.67 5.00 (G1) 3.00 09-12UT 3.67 5.67 (G2) 3.00 12-15UT 5.00 (G1) 4.67 (G1) 2.67 15-18UT 6.00 (G2) 3.67 2.00 18-21UT 7.67 (G4) 3.00 2.00 21-00UT 6.67 (G3) 3.00 3.00 Rationale: G4 (Extreme) storm levels are expected on 12 May due to CME impacts. G3 (Strong) geomagnetic storming is likely to continue into the early hours of 13 May. Isolated G1 (Minor) geomagnetic storming is likely on 14 May as conditions from the the previous days wane. 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 May 12-May 14 2024 May 12 May 13 May 14 S1 or greater 99% 60% 60% Rationale: S1 (Minor) solar radiation storms are expected through 14 May due to activity originating from AR 3634. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R2 levels were observed over the past 24 hours. The largest was at May 11 2024 1525 UTC. Radio Blackout Forecast for May 12-May 14 2024 May 12 May 13 May 14 R1-R2 95% 95% 95% R3 or greater 75% 75% 75% Rationale: R3 (Strong) or greater radio blackouts are expected all three days. ####018003542#### FXXX12 KWNP 121231 DAYDIS :Product: Forecast Discussion :Issued: 2024 May 12 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 was at moderate levels. Region 3664 (S18W67, Fkc/beta-gamma-delta) produced an M8.8/2b flare (R2/moderate) at 11/1525 UTC, the strongest of the period. Associated with the flare was a W oriented CME signature first observed in SOHO/LASCO C2 imagery beginning at 11/1612 UTC. An Earth-directed component is not suspected with the event. The region remained the most complex on the visible disk. The other numbered active regions were either mostly stable or in gradual decay. .Forecast... Solar activity is expected to be at high levels over 12-14 May, with M-class (R1-R2/Minor-Moderate) and X-class flares (R3/Strong) expected, due primarily to the flare potential of Region 3664. Energetic Particle .24 hr Summary... The greater than 10 MeV proton flux reached S1 (Minor) levels at 10/1335 UTC and S2 (Moderate) levels at 10/1745 UTC; a peak flux of 207 pfu was observed at 10/1745 UTC. The greater than 100 MeV proton flux decreased below the 1 pfu alert threshold at 12/0025 UTC. The greater than 2 MeV electron flux was at normal to moderate levels throughout the day. .Forecast... The greater than 10 MeV proton flux is expected to transition below S1 (Minor) storm levels on 12 May. Additional proton enhancements are likely on 13-14 May due to the flare potential and location of Region 3664. The greater than 2 MeV electron flux is expected to be at normal to moderate levels over 12-13 May, and is likely to increase to high levels on 14 May following a prolonged period of elevated geomagnetic activity and enhanced solar wind conditions. Solar Wind .24 hr Summary... The solar wind environment was strongly enhanced this period due to continued CME activity. Solar wind speeds reached a peak of around 1005 km/s at 12/0055 UTC. A gradual decline to the low 800s was interrupted by an abrupt increase to above 900 km/s after 12/0858 UTC, which suggested the arrival of another CME. Total magnetic field declined from a peak of 28 nT early in the reporting period to a low of 5 nT. An abrupt increase to 11 nT was observed at 12/0858 UTC. The Bz component maintained a northward orientation through after 12/0230 UTC. .Forecast... A strongly enhanced solar wind environment and continued CME influences are expected to continue on 12-13 May, and begin to wane by 14 May as CME influences subside. Some CH HSS influences are likely over 13-14 May, though CME influences are expected to be the primary driver of geomagnetic activity. Geospace .24 hr Summary... The geomagnetic field reached G4 (Severe) geomagnetic storm levels in the past 24 hours due to continued CME activity. .Forecast... Periods of G3 (Strong) geomagnetic storms are likely, with isolated G4 (Severe) levels possible, on 12 May due to continued CME passages from eruptive events originating from Region 3664 continues. Periods of G1-G3 (Minor-Strong) storming are likely on 13 Apr due to continued CME activity and positive polarity CH HSS influences. Periods of G1 (Minor) storms are likely on 14 May due to waning CME influences and CH HSS influences.