Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
862 FXXX12 KWNP 021231 DAYDIS :Product: Forecast Discussion :Issued: 2025 Dec 02 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 returned to low levels with only C-class flares. Region 4288 (N19W87, Dai/beta) remained quiet while Region 4291 (S11W72, Hrx/alpha) experienced decay as it lost its trailing spots, overall simplifying the region. Region 4294 (S15E30, Fkc/beta-gamma-delta) maintained a few delta signatures, making it the largest and most magnetically complex region on the disk, despite losing one of the more prominent deltas in the positive field of its trailing group. Region 4296 (S14E49, Eki/beta-gamma), like its leading bigger brothe, only produced low-level C-class flares as well while gaining a relatively small amount of separation between its leading and trailing spots. Region 4299 (N23E55, Dac/beta-gamma-delta), which had previously produced an X1.9 flare as it entered the disk, was not as eye-catching this period as it rotated off the eastern limb. Region 4300 (N08E64, Hsx/alpha) was numbered, but classification remains difficult due to foreshortening effects. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Isolated to occasional M-class flares are expected (75%) through 4 Dec, with a chance for X-class flares (30%), given past flare history and the potential of current active regions on the disk. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux in geosynchronous orbit continued at high levels with a peak flux of 2,210 particle flux units that was reached near 02/0200 UTC. The greater than 10 MeV proton flux in geosynchronous orbit remained at background levels. .Forecast... The greater than 2 MeV electron flux is expected to continue to at high levels, although gradually decreasing, through 03 Dec. A return to moderate levels by 04 Dec is likely with the initial onset of fast solar wind associated with a coronal hole high speed stream and/or shock arrival from the 01 Dec event. An enhancement to the 10 MeV proton flux in geosynchronous orbit due to the aforementioned X1.9 event from 01 Dec cannot be ruled out as sometimes events from the eastern limb take tens of hours to days to reach Earth. This combined with the flare potential currently exhibited by Earth-facing active regions will keep 10 MeV protons at a slight risk (20%) of reaching the 10 particle flux unit threshold through 04 Dec. Solar Wind .24 hr Summary... Solar wind parameters reflected waning positive polarity coronal hole high speed stream influences of the polar extension variety. Total interplanetary magnetic field values ranged from 4 to 7 nT, while the Bz component (North/South) was benign. Solar wind speeds, as measured by NASAs ACE spacecraft, gradually decreased from near 500 km/s to just under 400 km/s by the end of the reporting period. Phi was oriented in the positive solar sector with only a couple of very brief excursions into the negative sector. .Forecast... An overall gradual trend towards a more ambient-like environment is expected to continue for the remainder of 02 Dec. Disturbances in the solar wind environment are anticipated to return and arrive at Earth beginning by late on 03 Dec. First, phi is expected to enter the negative solar sector followed by the arrival of enhanced magnetic field ahead of fast solar wind associated with a recurrent, equatorial, negative polarity coronal hole high speed stream. This disturbance may be further enhanced by the glancing blow from the shock produced by a eastern limb coronal mass ejection that was associated with the aforementioned X1.9 flare on 01 Dec. While the disturbances from shock arrivals are typically brief, the enhancements of this combined phenomena is anticipated to continue through 04 Dec. Geospace .24 hr Summary... Geomagnetic field activity was quiet with an isolated unsettled period early on 02 Dec. .Forecast... The geomagnetic field is expected to remain at quiet to unsettled levels 02 Dec and into 03 Dec. Quiet to unsettled levels are likely to give way to G1-G2 (Minor-Moderate) storming periods by late 03 Dec due to the phenomena described in the solar wind section. G1-G2 (Minor-Moderate) storming is then likely to continue into 04 Dec. It should also be noted that a chance (25%) for isolated periods of G3 (Strong) geomagnetic storming will exist on 03 and 04 Dec, especially if the corotating interaction region ahead of the high speed stream arrives with embedded shock from the 01 Dec CME. Otherwise, G1-G2 (Minor-Moderate) conditions will most likely give way to mostly active levels as 04 Dec draws to a close. -WC