Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
352 FXXX12 KWNP 180031 DAYDIS :Product: Forecast Discussion :Issued: 2024 Sep 18 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 was at low levels. The largest flare was a C4.4 at 17/0640 UTC from Region 3828 (S13E61, Hhx/alpha). Slight growth occurred in Region 3825 (S15E06, Ekc/beta-gamma). Region 3824 (S04W54, Eai/beta-gamma) appeared to have decay in its intermediate and trailing spots. New Region 3829 (N11W59, Cro/beta) was numbered. No Earth-directed CMEs were observed. .Forecast... Solar activity is likely to reach moderate (R1-R2, Minor-Moderate), with a slight chance for X-class flares (R3-Strong), on 18-19 Sep. Probabilities are decreasing to a chance for M-class flares on 20 Sep as Regions 3824 and 3826 rotate around the W limb. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was at moderate to high levels with a peak flux of 2,390 pfu at 17/0130 UTC. The greater than 10 MeV proton flux levels increased above the S1 (Minor) threshold at 17/0735 UTC, reached a peak flux of 33.6 pfu at 17/1050 UTC, and crossed below threshold at 17/1615 UTC. Levels are still elevated near 5 pfu. .Forecast... The greater than 2 MeV electron flux is expected to be at normal to moderate levels on 18-20 Sep due to CME influence. The greater than 10 MeV proton flux is expected to slowly diminish over 18-20 Sep. Solar Wind .24 hr Summary... Solar wind parameters were indicative of CME influences. At 16/2249, the total magnetic field increased from 9-16 nT, reaching a peak of 20 nT at 17/0137 UTC, while Bz turned mostly southward reaching -18 nT. Solar wind speeds also increased at that time, from approximately 440 km/s to around 550 km/s. This activity indicated the shock arrival from the 13-14 Sep CMEs. Total field slowly diminished through the day to near 9 nT with solar wind speed decreasing to near 480 km/s. .Forecast... CME influence is expected to slowly wane through 18 Sep. A return to near nominal levels is expected on 19-20 Sep. Geospace .24 hr Summary... The geomagnetic field reached G4 (Severe) storm levels early in the period due to the arrival of the 14 Sep CME. CME activity persisted through the day causing further G1-G3 (Minor-Strong) geomagnetic storm levels. .Forecast... Unsettled to G1 (Minor) storm levels are expected early on 18 Sep as CME effects wane. Quiet to unsettled levels are expected on 19 Sep followed by mostly quiet conditions on 20 Sep.