Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
795 FXXX12 KWNP 210031 DAYDIS :Product: Forecast Discussion :Issued: 2026 Aug 21 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. Region 4513 (N04E69, Dac/beta) produced an M8.1/Sf (R2-Moderate) flare at 20/1142 UTC, the strongest of the period. Associated with event was a Type II radio sweep (est. 1,201 km/s) and a subsequent CME signature in coronagraph imagery. Analysis of the CME suggested no Earth-directed component. The region produced two other R1 (Minor) events, an M1.8/Sf at 20/0805 UTC and an M2.9/1F at 20/1611 UTC. A Type II event (est. 927 km/s) was observed beginning at 20/1848 UTC but associated with activity behind the W limb. A region of flux was observed rotating around the SW limb. Only minor changes were observed in spotted regions in the eastern hemisphere. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be at low levels, with a chance for isolated M-class flares (R1-R2/Minor-Moderate), over 21-23 Aug. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit remained at normal 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 likely to cross the 1,000 pfu threshold on 21 Aug, and remain at high levels on 22-23 Aug due to CH HSS influences. The greater than 10 MeV proton flux is expected to continue at background levels through 23 Aug. Solar Wind .24 hr Summary... Solar wind parameters continued to reflect the influences of a negative polarity coronal hole HSS. Total magnetic field strength was at or below 6 nT. The Bz component reached as far south as -5 nT. Solar wind speeds were in gradual decline, with peak speeds observed near 600 km/s and lows near 500 km/s by the end of the reporting period. .Forecast... Solar wind parameters near Earth are likely to continue reflecting waning influence of a negative polarity coronal hole high speed stream through 23 Aug. Geospace .24 hr Summary... The geomagnetic field activity was quiet to unsettled during the period. .Forecast... The geomagnetic field is likely to reach active levels over 20-22 Aug as the ongoing CH HSS influences near Earth wane. Unsettled levels are likely on 23 Aug.