####018002391#### FXXX10 KWNP 161231 DAYTDF :Product: 3-Day Forecast :Issued: 2024 May 16 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 6 (NOAA Scale G2). The greatest expected 3 hr Kp for May 16-May 18 2024 is 6.00 (NOAA Scale G2). NOAA Kp index breakdown May 16-May 18 2024 May 16 May 17 May 18 00-03UT 2.67 2.33 2.33 03-06UT 3.33 1.33 1.67 06-09UT 6.00 (G2) 1.67 2.00 09-12UT 4.67 (G1) 1.67 2.33 12-15UT 5.67 (G2) 2.33 2.33 15-18UT 4.67 (G1) 2.33 2.33 18-21UT 3.33 3.33 2.33 21-00UT 3.33 4.33 2.33 Rationale: G1-G2 (Minor-Moderate) geomagnetic storms are likely on 16 May due to transient influences possibly combined with a positive polarity CH HSS. 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 16-May 18 2024 May 16 May 17 May 18 S1 or greater 99% 15% 10% Rationale: R1-R2 (Minor-Moderate) conditions are expected on 16 May due to the flare potential from now departed Region 3664. Probabilities drop to a slight chance on 17-18 May from the remaining active regions on the Suns visible disk. 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 15 2024 1438 UTC. Radio Blackout Forecast for May 16-May 18 2024 May 16 May 17 May 18 R1-R2 75% 40% 40% R3 or greater 40% 10% 10% Rationale: R1-R2 (Minor-Moderate) conditions are expected on 16 May due to the flare potential from now departed Region 3664. Probabilities drop to a chance on 17-18 May from the remaining active regions on the Suns visible disk. ####018003779#### FXXX12 KWNP 161231 DAYDIS :Product: Forecast Discussion :Issued: 2024 May 16 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. Newly numbered Region 3685 (S14E70, Dso/beta) produced an X2.9 flare at 15/1438 UTC, resulting in a Type II radio sweep with an estimated speed of 1,064 km/s and a Type IV radio sweep. This event produced a CME, but is not Earth-directed. This AR also produced an M1.0 flare at 16/0804 UTC. Region 3679 (S09E25, Dso/beta-gamma-delta) underwent evolution as it began to form a weak delta signature in its leading, large penumbra. Regions 3670 (N20W58, Dao/beta-gamma), 3676 (S22W41, Cso/beta-gamma) and 3682 (N13E37, Cso/beta-gamma) all maintained their gamma configurations, but were relatively quiet. Region 3683 (S23W15, Dro/beta) developed rapidly this period and was numbered, but remained quiet as well. Region 3684 (S06E61, Bxo/beta) was numbered but was inactive. Beginning at approximately 15/1024 UTC, a northerly CME was observed in SOHO C2 coronagraph imagery. The source of this event appears to be a surge and brightening in the vicinity of a large filament centered near N35E35 at approximately 15/0939 UTC in GOES-16 SUVI 304 angstroms. Analysis and modeling of this event determined the CME to not be Earth-directed. .Forecast... Solar activity is expected to be at high levels due to M-class flare activity (R1-2/Minor-Moderate Radio Blackouts) with a chance for X-class flares (R3 Strong) through 16 May. Probabilities decrease somewhat on 16-17 May to a chance for M-class flares as Region 3664 rotates further beyond the western limb. Energetic Particles .24 hr Summary... The greater than 10 MeV proton flux was at S1 (Minor) solar radiation storm levels with a peak flux of 30 pfu at 15/1315 UTC. The 2 MeV electron flux reached high levels with a peak flux of 1,500 pfu at 15/1840 UTC. .Forecast... The greater than 10 MeV proton flux is expected to remain at S1 (Minor) solar radiation storm levels over most of 16 May. Background levels are expected thereafter. The 2 MeV electron flux is expected to be at moderate to high levels on 16 May and then normal to moderate levels 17-18 May. Solar Wind .24 hr Summary... Solar wind parameters were indicative of waning CME and positive polarity CH HSS influences until 15/1816 UTC when a weak shock feature became prevalent. A secondary enhancement was observed near 16/0500 UTC. At this time total field increased to a maximum of 17 nT and the Bz component deflected southward, reaching a southward deviation of -13 nT. Solar wind speeds averaged near ~450 km/s. Phi was predominantly oriented in a positive solar sector until near 16/0700 UTC, when it became variable. .Forecast... The aforementioned enhancement that is likely due to glancing influences from a CME that originated from AR 3664 back on 13 May is likely to continue over the course of the early parts of 16 May. An additional enhancement from a filament eruption that left the sun on 14 May is anticipated to materialize by late 17 May and will likely persist into 18 May. Geospace .24 hr Summary... The geomagnetic field reached G2 (Moderate) storm levels. .Forecast... Quiet to unsettled conditions, with isolated G1-G2 (Minor-Moderate) storm levels, are expected 16-17 May due to weak CME effects. Quiet to unsettled levels are expected to prevail on 18 May as any weak CME effects slowly wane.