Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
790 FXXX12 KWNP 210031 DAYDIS :Product: Forecast Discussion :Issued: 2026 Jul 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 due to M-class flare activity. Region 4493 (N05E09, Dac/beta-gamma-delta) underwent rapid flux emergence and developed compact spots with asymmetric penumbra and exhibited mixed polarity in its intermediate area. AR 4493 was responsible for three impulsive M-class flares: an M2.5 flare at 20/1436 UTC, an M1.1 flare at 20/1920 UTC, and an M3.4 flare at 20/2225 UTC. Region 4491 (S11E08, Bxo/beta) exhibited decay and the remaining two active regions were relatively stable and quiet in comparison. An approximately 12-degree long east to west filament disappeared just after 20/0400 UTC. A likely associated CME that resulted from material that was not reabsorbed was then first observed in LASCO C2 coronagraph imagery around 20/0536 UTC. Modeling of this event, along with another CME that left the Sun on 19 July, suggests both events to miss ahead of Earth. Additional CMEs observed during the period were the result of far side activity and are not anticipated to have an Earth-directed component. .Forecast... A high chance (40%) for additional R1-R2 (Minor-Moderate) radio blackouts due to M-class flare activity, primarily from AR 4493, will persist through 23 July. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels this period with a peak flux of 1,300 pfu at 20/1730 UTC. The greater than 10 MeV proton flux was steady at background levels. .Forecast... The greater than 2 MeV electron flux is expected to return to normal to moderate levels on 21 July with a chance to reach high levels once again by late on 22 July and continuing into 23d July. The greater than 10 MeV proton flux is expected to continue at background levels through 23 Jul with a 5% chance for an S1 or greater event primarily due to the event potential currently presented by AR 4493. Solar Wind .24 hr Summary... Solar wind parameters continued at background levels. Total magnetic field strength averaged 4 nT, the Bz component ranged between 2 and -4 nT, and solar wind speeds were largely below 300 km/s. Phi was predominantly in a positive orientation. .Forecast... Late on 21 Jul, a CIR ahead of a negative polarity CH HSS is likely to move into a geoeffective position, bringing enhancements to the solar wind environment and persisting through 23 July. Geospace .24 hr Summary... The geomagnetic field was quiet under an ambient solar wind environment. .Forecast... Primarily quiet conditions are expected for a majority of 21 July. G1 (Minor) geomagnetic storming is likely on 22 July due to onset of negative polarity CH HSS effects. Unsettled to active conditions are then expected on 23 July as CH HSS effects persist.