Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
381 FXXX12 KWNP 120031 DAYDIS :Product: Forecast Discussion :Issued: 2026 Aug 12 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 low levels, with the largest event of the period being a C2.5 flare at 11/2304 UTC from Region 4507 (N04E43, Cri/beta). There are four numbered regions on the visible disk. Region 4503 (S17W26, Bxo/beta) was in decline with the submergence of its trailing spots. Region 4506 (N11E26, Bxo/beta) featured small spots emerging around its leading spot. Region 4507 exhibited modest new flux emergence and convergence, becoming active late in the period and producing two C-class flares. Region 4508 (N06E70, Hsx/alpha) continued to rotate into view, though proximity to the limb hindered definite characterization. Solar Orbiter PHI imagery from 08 Aug suggested opposite-polarity trailing spots but none have been observed as yet. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be low with a negligible chance for M-class (R1-R2/Minor-Moderate) flares 12-14 Aug. Solar Orbiter PHI imagery indicates another region should rotate onto the visible disk behind and to the South in the coming day, but available imagery suggests it is not especially large or complex. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit was at moderate levels and reached a peak flux of 734 pfu observed at 11/1340 UTC. The greater than 10 MeV proton flux at geosynchronous orbit remained at background levels. .Forecast... The greater than 2 MeV electron flux is expected to remain at low to moderate levels through 14 Aug. The greater than 10 MeV proton flux is expected to remain at background levels 12-14 Aug. Solar Wind .24 hr Summary... Solar wind parameters reflected nominal slow-wind background conditions prior to an interplanetary shock arrival at 11/1032 UTC that is presumed to be the arrival of the 08 Aug CME. Pre-shock parameters were near 5 nT for total field (Bt), speeds near 340 km/s, and a phi angle firmly in the negative (towards the Sun) sector. Upon shock passage at 11/1032 UTC, Bt jumped sharply to 9 nT (eventually reaching a peak near 10.2 nT), while solar wind speeds increased to over 400 km/s. The North-South component (Bz) experienced an approximately 3-hour deflection southward and reached -8 nT. Later in the period, Bz shifted predominantly northward. The phi angle was variable following shock arrival. .Forecast... CME-related enhancements are expected to persist into 12 Aug. Additional low-confidence enhancements are possible from a small positive polarity coronal hole on 12 Aug before parameters continue a downward trend on 13 Aug. Enhancements are expected to return under the influence of a positive polarity coronal hole high-speed stream (+CH HSS) by mid to late on 14 Aug. Geospace .24 hr Summary... A Sudden Impulse (SI) with a deviation of 12 nT was recorded at Boulder at 11/1133 UTC following the interplanetary shock. The geomagnetic field was quiet preceding the shock arrival before reaching unsettled levels due to post-shock solar wind variations. .Forecast... Geomagnetic activity is expected to be mostly quiet with isolated unsettled periods on 12 Aug, returning to quiet conditions on 13 Aug. Active conditions with a chance for G1 (Minor) storming or greater are likely on 14 Aug under +CH HSS influences.