####018003865#### FXXX12 KWNP 091231 DAYDIS :Product: Forecast Discussion :Issued: 2024 May 09 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 high levels with background flux at or near M1.0. Region 3664 (S19W31, Fkc/beta-gamma-delta) continued to grow and eventually merged with Region 3668 (S15W21). This new combined spot group will maintain the 3664 region designation, and is now over 1,500 millionths in size. AR 3664 produced many M-class flares and two X-class flares in the past 24-36 hours. Within that activity, three halo CMEs were associated with expected arrivals on late 10 to early 11 May. A fourth halo CME associated with the X2.2/3B flare is visible in STEREO imagery. LASCO coronagraph imagery has yet to update to further analyze this event. Region 3663 (N26W77, Fkc/beta-gamma) exhibited signs of decay as it approached the western limb, and appears to be losing its delta configuration. However, this region continued to produce optical flares, radio bursts, and an isolated M-class flare. The remaining spotted active regions were stable and inactive. Other activity included an approximately 35° long filament that erupted, centered near E27N18, with an associated CME, mostly moving in a northeasterly direction. Analysis and modeling of this event determined a possible Earth-directed component with similar timing to the halo CMEs mentioned above. .Forecast... Solar activity is expected to persist at high to very high levels over 09-11 May, with M-class flares (R1-R2/Minor-Moderate) expected and X-class flares (R3/Strong) likely, due to the continued flare potential of Region 3663 and especially Region 3664. 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 was steady at background levels. .Forecast... The greater than 2 MeV electron flux is expected to continue at normal to moderate levels over 09-11 May. There is a chance for the greater than 10 MeV proton flux to reach S1 (Minor) storm levels over 09-11 May due to the flare potential of Regions 3663 and 3664. Solar Wind .24 hr Summary... The solar wind environment reflected near-background conditions, with the exception of slightly elevated solar wind speeds, likely attributed to residual CH HSS influence. Total field strength was steady near 3 nT, the Bz component had no significant southward deflections, Phi remained in a positive orientation, and solar wind speeds averaged near 470 km/s. .Forecast... Possible enhancements in the solar wind environment are likely on 09 May, following the anticipated glancing effects of a CME that departed the Sun on 06 May. Late on 10 May and into 11 May, stronger enhancements are likely as the two CMEs that departed the Sun on 08 May are anticipated to arrive at Earth. Geospace .24 hr Summary... The geomagnetic field was at quiet levels. .Forecast... Mid to late day on 09 May, unsettled to active conditions are possible as glancing effects from a CME that departed the Sun on 06 May are anticipated to influence Earth. By late on 10 May, the two halo CMEs from 8 May are anticipated to arrive at Earth, increasing the geomagnetic response to G1 (Minor) storm levels. Early on 11 May, conditions are likely to reach G3 (Strong) storm levels as the bulk of four CMEs moves past Earth. While confidence in timing is fairly high, confidence in magnitude/strength of the geomagnetic response to the CME arrival is low to moderate. ####018002221#### FXXX10 KWNP 091231 DAYTDF :Product: 3-Day Forecast :Issued: 2024 May 09 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 May 09-May 11 2024 is 6.67 (NOAA Scale G3). NOAA Kp index breakdown May 09-May 11 2024 May 09 May 10 May 11 00-03UT 1.00 3.33 5.67 (G2) 03-06UT 2.00 4.00 6.67 (G3) 06-09UT 1.00 4.00 5.33 (G1) 09-12UT 2.33 4.33 5.00 (G1) 12-15UT 3.33 4.33 5.00 (G1) 15-18UT 3.67 5.00 (G1) 5.00 (G1) 18-21UT 2.67 5.33 (G1) 4.67 (G1) 21-00UT 2.67 5.33 (G1) 4.67 (G1) Rationale: G1 (Minor) to G3 (Strong) geomagnetic storms are likely on 10-11 May due to the arrival of CMEs from 07-08 May. 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 May 09-May 11 2024 May 09 May 10 May 11 S1 or greater 25% 25% 25% Rationale: A chance for S1 (Minor) solar radiation storms will persist through the forecast period given the observed activity from AR 3664 in particular. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R3 levels were observed over the past 24 hours. The largest was at May 09 2024 0913 UTC. Radio Blackout Forecast for May 09-May 11 2024 May 09 May 10 May 11 R1-R2 95% 95% 95% R3 or greater 60% 60% 60% Rationale: R3 (Strong) radio blackouts due to X-class flares are likely through the forecast period primarily due to the magnetic complexity and stature of AR 3634.