Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
736 FXXX12 KWNP 171231 DAYDIS :Product: Forecast Discussion :Issued: 2026 May 17 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 moderate levels. Region 4436 produced an M1.9 flare at 16/1612 UTC which was followed by an M1.3 flare at 16/1629. This event was associated with a Type IV radio sweep that began at approximately 16/1605 UTC, a filament eruption that was centered at approximately N21W07 and resulted in a complex CME eruption. The first front of this event was first seen in LASCO C2 coronagraph imagery at 16/1636 UTC with the second becoming visible near 16/1700 UTC. Initial analysis and model output suggests a glancing blow to Earth by mid UTC-day with a bulk of the material passing northward of Earth on 18 May. .Forecast... Solar activity is likely to be at low levels, with a chance for additional M-class (R1-R2/Minor-Moderate) flares through 19 May. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux increased to high levels. The greater than 10 MeV proton flux was at background levels. .Forecast... The greater than 2 MeV electron flux is expected to remain at moderate to high levels through 19 May. The greater than 10 MeV proton flux is expected to stay at background levels through 18 May. Solar Wind .24 hr Summary... The solar wind parameters reflected continued influence of a negative polarity coronal hole. Total magnetic field strength was steady near 5nT. The Bz component varied between +/- 5 nT. Solar wind speeds were mostly between 600-700 km/s. Phi angle was predominantly oriented in a negative solar sector. .Forecast... A negative polarity CH HSS regime is expected to persist through 19 May. Additional enhancements are possible on 18 and 19 May due to aforementioned glancing CME influences. Geospace .24 hr Summary... The geomagnetic field reached G1 (Minor) geomagnetic storm levels during early in the reporting period due to influence from a -CH HSS. .Forecast... G1 (Minor) geomagnetic storming is likely on 17 May due to continued CH HSS effects. G1 (Minor) geomagnetic storming, with a chance for G2 (Moderate) levels, are likely once again on 18 May due to any glancing CME effects from the aforementioned event. A chance for G1 (Minor) storming will extend into 19 May.