Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
043 FXXX12 KWNP 181231 DAYDIS :Product: Forecast Discussion :Issued: 2025 Aug 18 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 was at low levels. The strongest event of the period was a C3.3/Sf at 17/1958 UTC from Region 4140 (S02W17, Cao/beta). Only minor changes were observed among the numbered active regions on the visible disk. Other activity included a subtle eruption near the vicinity of S12W15 between 17/0900-1000 UTC. A subsequent CME signature was identified in SOHO LASCO C2 imagery beginning at 17/1024 UTC. Analysis and modeling of the CME suggested it was mostly a miss, but a slight glancing blow was possible mid to late on 20 August. .Forecast... There is a chance for solar activity to persist at low levels on 18-20 August. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels with a peak flux of 8,023 pfu observed at 17/1555 UTC. The greater than 10 MeV proton flux remained at background level. .Forecast... The greater than 2 MeV electron flux is expected to be at moderate to high levels through 20 Aug. The greater than 10 MeV proton flux is expected to remain at background levels through 20 Aug. Solar Wind .24 hr Summary... Solar wind parameters reflected nominal conditions. Total magnetic field strength was at 5-6 nT through most of the day with increases to 10 nT by periods end. No significant periods of southward Bz were observed with some southward excursions to 5-6 nT at the end of the period. Solar wind speeds remained slow with values remaining between ~300-350 km/s. Phi angle was predominately oriented in the positive solar sector. .Forecast... Enhanced solar wind parameters are likely on late on 18 Aug and through 20 Aug due to the arrival of a CIR ahead of a recurrent, negative polarity CH HSS. Geospace .24 hr Summary... The geomagnetic field was at quiet levels. .Forecast... The geomagnetic field is likely to continue at quiet levels over most of 18 Aug. Late on 18 Aug, conditions are likely to increase to active levels followed by G1 (Minor) geomagnetic storm levels on 19 Aug. Active conditions are likely on 20 Aug. The increases in activity are due to the anticipated onset of influence from a recurrent, negative polarity CH HSS and a possible weak, glancing blow on 20 Aug from the 17 Aug CME.