Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
651 FXXX12 KWNP 201231 DAYDIS :Product: Forecast Discussion :Issued: 2025 Sep 20 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 increased to moderate levels. Region 4216 (N10W45, Dso/beta-gamma) produced an impulsive C5.8 flare at 19/2112 UTC. This was immediately followed by an M1.5/3n flare at 19/2141 UTC. During the period this region indicated some overall spot and area decay, but maintained a beta-gamma magnetic configuration. Region 4219 (N24W84, Axx/alpha) was the culprit for a C2.6 flare at 20/0452 UTC as it underwent overall decay. Region 4220 (S19W41, Dhi/beta-gamma) exhbited decay primarily in its intermediate area while Region 4223 (S15E07, Cao/beta) experienced evolution, gaining additional spots. Regions 4226 (S11E67, Hsx/alpha) and 4227 (S17E67, Hsx/alpha) were observed and numbered, but were relatively quiet. No Earth directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be low, with a chance for an isolated M-class flare (R1-R2/Minor-Moderate), through 22 Sep. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels with a peak flux of 5,022 pfu observed at 19/1205 UTC. The greater than 10 MeV proton flux was at background levels. .Forecast... The greater than 2 MeV electron flux is expected to continue at moderate to high levels through 20 Sep. A decrease to moderate levels is likely by late on 21 Sep due to the arrival of a CIR/CH HSS. A chance for high levels is then anticipated on 22 Sep. The greater than 10 MeV proton flux is expected to persist at background levels. Solar Wind .24 hr Summary... Solar wind parameters returned to nominal levels. Total field primarily ranged 2-4 nT and the Bz component was at or near neutral. Solar wind speeds gradually decreased from just above 400 km/s to approximately 350 km/s. Phi was predominantly in the negative solar sector. .Forecast... Solar wind parameters are expected to continue at nominal levels through late on 21 Sep when an enhancement from a negative polarity CH HSS is expected to become geoeffective. Elevated conditions are expected to persist through 22 Sep. Geospace .24 hr Summary... The geomagnetic field was at quiet levels. .Forecast... Mostly quiet conditions are expected through most of 21 Sep. Unsettled to active conditions, with isolated G1 (Minor) geomagnetic storming levels likely, are expected by late on 21 Sep/early on 22 Sep due to CH HSS onset.