####018004478#### FXXX12 KWNP 020031 DAYDIS :Product: Forecast Discussion :Issued: 2024 May 02 0030 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 moderate, with six designated sunspot groups and background X-ray flux at mainly C-class levels. Region 3654 (S07W76, Fkc/beta-delta) began the period in the diminishing phase of an M9.5/2b flare (R2-Moderate) that peaked at 30/2346 UTC. The region also produced an M1.8/Sn flare (R1-Minor) at 01/1432 UTC. The region has become considerably foreshortened now that it nears the southwest limb, so an accurate analysis is not as possible - however, it is apparent that the spot group retained its mixed polarity configuration in at least the intermediate section and remained unstable. Regions 3662 (N30W01, Dao/beta) and 3663 (N26E25, Dso/beta-gamma) underwent growth during the period, with Region 3663 developing more maturity, some magnetic polarity mixing, and more low-level activity. This region was also the culprit of an M1.8 flare at 01/2331 UTC. New Region 3664 (S18E64, Dao/beta) rotated into view and was numbered this period. Another notable event was a long duration C5.8 flare that peaked at 01/0758 UTC. This activity occurred from just south of, but in the vicinity of Region 3654. A large CME associated with this activity was detected in SOHO/LASCO coronagraph imagery and has been analyzed extensively with varied results. See solar wind and geospace forecast sections below for more discussion about this activity. .Forecast... Moderate solar activity is anticipated on 02 May, with M-class flares (R1-R2; Minor-Moderate) likely and a slight chance of an X-class flare (R3; Strong) event due primarily to the complexity and continued flare activity from Region 3654. Solar activity will likely decrease to low levels, with a decreasing chance of M-class flares on 03-04 May as Region 3654 rotates to and beyond the solar limb. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was normal to moderate and the greater than 10 MeV proton flux maintained background levels. .Forecast... The greater than 2 MeV electron flux is likely to continue at normal to moderate levels 02-04 May. There is a slight chance of an S1 (Minor) storm on 02 May due to the slight risk of a solar energetic particle event from the favorably located sunspot complex, Region 3654. This region will begin rotating beyond the limb on 03 May, resulting in decreased chances of S1 storm potential. Solar Wind .24 hr Summary... Solar wind parameters were indicative of transient progression. Total IMF strength ranged from 10-13 nT much of the period, however, the Bz component rotated northward early and remained so most the day. Solar wind speed decreased from a peak ~425 km/s to near 350 km/s. The phi angle was variable until about 01/1025 UTC, when it settled into a positive sector. .Forecast... Transient passage influences are likely to wane on 02 May, however, additional nearby CME passages or glancing influences are possible through 03 May. Also, several isolated CH HSS flows are anticipated to affect the solar wind, keeping a disturbed and enhanced field present. Finally, a mainly southwest directed CME associated with the aforementioned long-duration C5 flare has been analyzed and modeled. Results are mixed, so there is a fair amount of uncertainty regarding this CME. However, there is some consensus that a flanking edge shock arrival at Earth later on 04 May is feasible. Geospace .24 hr Summary... The transient effects led to a disturbed field early in the reporting period as active levels of response were reached. The remainder of the day experienced mainly quiet to unsettled conditions. .Forecast... A mix of transient and CH HSS effects are likely to lead to variable geomagnetic responses 02-03 May from quiet periods to active levels. Dependent upon the 01 May CME transit and path, geomagnetic response could escalate to active levels later on 04 May, with a chance of G1 (Minor) storm levels. This CME continues to be analyzed for a final determination of geoeffective potential. ####018002337#### FXXX10 KWNP 020031 DAYTDF :Product: 3-Day Forecast :Issued: 2024 May 02 0030 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 May 02-May 04 2024 is 4.33 (below NOAA Scale levels). NOAA Kp index breakdown May 02-May 04 2024 May 02 May 03 May 04 00-03UT 2.33 3.67 3.33 03-06UT 3.33 3.33 2.33 06-09UT 2.67 3.00 3.00 09-12UT 2.33 3.33 2.67 12-15UT 3.00 3.00 2.67 15-18UT 3.33 3.33 4.00 18-21UT 4.00 3.33 4.33 21-00UT 4.33 3.67 4.33 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 May 02-May 04 2024 May 02 May 03 May 04 S1 or greater 10% 5% 5% Rationale: A slight chance for an S1 (Minor) solar radiation storm will exist on 02 May given the relatively recent activity from AR 3654 and its current location. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at May 01 2024 1444 UTC. Radio Blackout Forecast for May 02-May 04 2024 May 02 May 03 May 04 R1-R2 55% 40% 30% R3 or greater 10% 5% 5% Rationale: R1-2 (Minor-Moderate) radio blackouts due to M-class flare activity remain likely on 02 May given the flare histories of ARs 3654 and 3663. Probabilities decrease to a just a chance 03-04 May as AR 3654 rotates off the visible disk.