Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
420 FXXX12 KWNP 091231 DAYDIS :Product: Forecast Discussion :Issued: 2026 Oct 09 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 reached high levels as Region 4549 (N10W41, Eki/beta-gamma-delta) produced the largest flare of the period, an M6.7/2b at 08/1548 UTC. Associated with the flare were Type II and Type IV radio emissions, along with an EUV wave seen in GOES/SUVI imagery. The Type II had an estimated speed, reported by Sagamore Hill (USAF RSTN site) of approx. 4,125 km/s. However, analysis of the CME first observed in by SWPC forecasters indicates speeds closer to the 900 km/s range. Modeling suggests this CME is likely to arrive at Earth on 11 Oct. A filament erupted just SW of disk center beginning at approximately 08/1815 UTC; however, no associated CME signatures have been observed in available coronagraph imagery. Region 4545 (N18W46, Dro/beta) continued to exhibit decay. Region 4549 showed separation between the leading and trailing spots, with the east-west oriented delta continuing to bisect the leader spots, increasing the potential for magnetic shearing. Region 4548 (S13W01, Hsx/alpha) remained stable and inactive. A new region rotated onto the east limb in the south and was numbered Region 4551 (S13E71, Dso/beta). .Forecast... Solar activity is expected to be at low levels (85%) with M-class flares (R1-R2, Minor-Moderate) likely (55%) through 11 Oct, primarily due to the flaring potential of Region 4549. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels in the beginning of the period, with a peak of approx. 1100 pfu at 08/1250 UTC, and then decreased, crossing below the alert threshold at 08/2145 UTC. The greater than 10 MeV proton flux was slightly elevated above background levels but still well below the alert threshold. .Forecast... The greater than 2 MeV electron flux is expected to reach normal to moderate levels through 11 Oct. There is a slight chance (10%) for a greater than 10 MeV proton event exceeding the 10 pfu (S1-Minor) threshold through 11 Oct. Solar Wind .24 hr Summary... Solar wind parameters were at background levels during the first half of the reporting period: solar wind speed averaged near 350 km/s, total field averaged 5 nT, and the Bz component was weakly southward, with a phi angle largely positive. At approximately 09/0440 UTC, total field began slowly increasing, reaching a peak of 12 nT at 09/1045 UTC. Bz deflected predominantly southward with this field increase, reaching -8 nT several times throughout the later half of the period. .Forecast... Solar wind environment disturbances are likely to persist through the remainder of 09 Oct, likely giving way to a negative polarity coronal hole high speed stream regime on 10 Oct. Additional enhancements are anticipated on 11 Oct due to CMEs that left the Sun on 07-08 Oct. Geospace .24 hr Summary... The geomagnetic field was quiet to active. .Forecast... G1-G2 (Minor-Moderate) geomagnetic storm levels are likely on 09 Oct with the arrival of the 06 Oct CME events. Unsettled to active conditions are expected to then persist into and through 10 Oct as a negative polarity coronal hole high speed stream becomes geoeffective. G1-G2 are again anticipated on 11 Oct due to additional CME arrivals.