####018002693#### FXXX12 KWNP 300031 DAYDIS :Product: Forecast Discussion :Issued: 2026 May 30 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 reached moderate levels with an M1.1/sf at 29/0704 UTC from Region 4455 (N15E46, Eho/beta-gamma), the strongest of the period. No significant growth was observed among the spotted regions on the visible disk. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be at low to moderate levels through 01 Jun. There remains a chance for isolated M-class flares (R1-R2/Minor-Moderate), driven primarily by Regions 4452 and 4455. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit was at low to moderate levels. The greater than 10 MeV proton flux at geosynchronous orbit remained at background levels. .Forecast... The greater than 2 MeV electron flux is expected to remain at low to moderate levels through 01 Jun. The greater than 10 MeV proton flux is expected to remain at background levels. Solar Wind .24 hr Summary... The solar wind parameters suggested very mild negative polarity coronal hole high-speed stream (-CH HSS) influences. Total magnetic field (Bt) strength ranged primarily from 4 to 8 nT, and the north-south (Bz) component continued to be highly variable, with a peak southward deflection to -8 nT. The phi angle was predominantly in a negative (towards the Sun) sector. Solar wind speed ranged mainly between 400-450 km/s. .Forecast... Mild enhancements due to weak -CH HSS influences are likely to persist through 30 May. Further enhancements are possible on 30 May due to a CME that departed the Sun on 26 May. Additional solar wind enhancements are anticipated on 31 May due to the onset of a new -CH HSS, combined with possible glancing influences from the slow eruptions that departed the Sun on 27 and 28 May. Geospace .24 hr Summary... The geomagnetic field was quiet to active in response to -CH HSS influences. .Forecast... Geomagnetic field conditions are anticipated to be at quiet to active levels 30 May due to waning -CH HSS effects and potential glancing CME influences. Active conditions are again likely on 31 May in response to the combined onset of the new -CH HSS and glancing CME influences. Conditions are expected to be mostly quiet to unsettled by 01 Jun. ####018002182#### FXXX10 KWNP 300031 DAYTDF :Product: 3-Day Forecast :Issued: 2026 May 30 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 30-Jun 01 2026 is 4.00 (below NOAA Scale levels). NOAA Kp index breakdown May 30-Jun 01 2026 May 30 May 31 Jun 01 00-03UT 2.00 3.00 3.00 03-06UT 2.00 2.33 3.00 06-09UT 4.00 2.33 2.67 09-12UT 2.00 1.67 2.00 12-15UT 2.00 3.33 2.67 15-18UT 3.00 2.67 2.00 18-21UT 1.00 4.00 2.67 21-00UT 2.00 3.67 2.67 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 30-Jun 01 2026 May 30 May 31 Jun 01 S1 or greater 5% 5% 5% Rationale: No S1 (Minor) or greater solar radiation storms are expected. No significant active region activity favorable for radiation storm production is forecast. 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 29 2026 0704 UTC. Radio Blackout Forecast for May 30-Jun 01 2026 May 30 May 31 Jun 01 R1-R2 40% 40% 40% R3 or greater 5% 5% 5% Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts over 30 May-01 Jun.