Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
779 FXXX12 KWNP 310031 DAYDIS :Product: Forecast Discussion :Issued: 2025 Dec 31 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 has been at low levels for the past 24 hours, with few C-class flares mostly coming from Region 4325 (S08E17, Eki/beta-gamma). The largest flare of the period was a C5.0/Sf, peaked at 30/0645 UTC, from Region 4324 (N24E25, Dao/beta-gamma). Region 4330 (S16E41, Axx/alpha) was responsible for two eruptions seen in SUVI imagery. The first eruption was associated with a CME, first observed at coronagraph imagery at 30/0700 UTC and closely followed by a second CME from the northeast quadrant (potentially from near Region 4324). But none of their modeled trajectory indicated direct impact near-Earth. Further coronagraph images are necessary to evaluate if the second eruption from Region 4330 will result in a visible CME. No other Earth-directed CME was observed during the period. .Forecast... Solar activity is likely to be moderate with a chance for X-class flares through 02 Jan due to the current magnetic complexity and development of the active regions on the visible solar disk. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux, measured at geostationary orbit by GOES-19, reached a peak level of 5,612 pfu at 30/1545 UTC and decreased to moderate levels after 30/1915 UTC. The greater than 10 MeV proton flux remained at background levels during the period. .Forecast... The greater than 2 MeV electron flux is expected to reach high levels again on 31 Dec and 01-02 Jan. The greater than 10 MeV proton flux has a slight chance of crossing threshold on days 31 Dec, 01-02 Jan. Solar Wind .24 hr Summary... Solar wind parameters remained at background conditions during most of the day. Solar wind speed oscillated around 400 km/s, but reached a peak of 563 km/s at 30/1514 UTC during a brief disturbance. Total IMF oscillated around 5 nT most of the period, and reached 9 nT at 30/2323 UTC. The maximum southward component of Bz reached -6 nT at 30/1515 UTC, during a brief disturbance that was likely anticipating a sector crossing observed as the phi angle change (from mostly positive to mostly negative after that), likely associated with a negative CH HSS. .Forecast... Solar wind parameters are expected to increasingly respond to the influence of a negative CH/HSS located at the northwest solar quadrant in the next days: higher speeds, lower densities and negative phi angle. By late 31 Dec / early 01 Jan, a glancing blow of CME that left the Sun on 28 Dec is anticipated to disturb the solar wind near Earth. Later on 01 Jan, an extra disturbance caused by the multiple CMEs from 29 Dec is also possible. Geospace .24 hr Summary... The geomagnetic activity has been at quiet to unsettled levels for the past 24 hours. .Forecast... The geomagnetic activity is expected to be at quiet to active levels on 31 Dec, unsettled to minor storm levels on 01 Jan and unsettled to active levels on 02 Jan.