Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
582 FXXX12 KWNP 200721 DAYDIS :Product: Forecast Discussion :Issued: 2025 Aug 20 0720 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 decreased back to low levels with a few weak C-class flares observed from areas of plage located in the NE quadrant of the disk. There are currently three sunspot regions on the disk with the largest Region 4187 (). This region showed some weak leader spot growth. The remaining two regions were quiet and stable. At about 20/0430 UTC, a large provenance lifted off the SE limb. GOES X-rays observed a slow increase in flux values to peak at about C1.6 at 20/0711 UTC. LASCO C2 imagery observed a large CME off the SE limb first visible at 20/0500 UTC. Due to the eruptions location on or just behind the limb, no Earth-directed component is forecast. No other Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity will likely be at very low to low levels, with a slight chance for for M-class flares through 22 August due to the anticipated return of old active regions. Energetic Particles .24 hr Summary... The greater than 2 MeV electron flux was at normal to moderate levels. The greater than 10 MeV proton flux was at background levels. .Forecast... The greater than 2 MeV electron flux is expected to be at normal to moderate levels through 21 August due to high speed stream influences followed by the potential of periphery influences from a CME that left the Sun on 17 August interacting with the near-Earth environment. A return to high levels is possible on 22 August. The greater than 10 MeV proton flux is expected to continue at background levels through 22 August given the lack of dynamic regions. Solar Wind .24 hr Summary... Solar wind parameters reflected negative polarity CH HSS influences. Total field primarily ranged from 8-19 nT while the Bz component underwent a few brief deflections reaching -7 to -11 nT. Solar wind speeds increased from around 400 km/s at the beginning of the period to approximately 600-705 km/s as the HSS began to prevail. By about 20/0000 UTC, wind speeds slowly decreased to near 600 km/s. Phi was predominantly in the negative solar sector. .Forecast... A disturbed solar wind environment is likely to continue through 22 August due to recurrent, negative polarity CH HSS influences. An additional enhancement is also possible later on 20 August due to glancing effects from a CME that left the Sun on 17 August. Geospace .24 hr Summary... The geomagnetic field reached G1 (Minor) geomagnetic storming levels. .Forecast... The geomagnetic field is expected to reached G1 (Minor) geomagnetic storming levels, with a chance for an isolated G2 (Moderate) period, on 20 August due to continued CH HSS effects coupled with any glancing influences from a CME that left the Sun on 17 August. Unsettled to active levels are expected on 21 August as CH HSS and possible CME effects begin to wane with primarily quiet to unsettled conditions prevailing on 22 August.