Routine Space Environment Product Issued Weekly
Issued by NWS
Issued by NWS
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790 FXXX02 KWNP 210326 WEKFOR :Product: 27-day Space Weather Forecast :Issued: 2026 Sep 21 0317 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center # Product description and SWPC contact on the Web # https://www.swpc.noaa.gov/content/subscription-services # # 27-day Space Weather Forecast # Forecast of Solar and Geomagnetic Activity 21 September - 17 October 2026 Solar activity is expected to be at low levels, with a slight chance for moderate to high levels throughout the forecast period. No proton events are expected at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 26-30 Sep, 01-03 Oct, and 05-11 Oct. Low to moderate levels are expected on 21-25 Sep, 04 Oct, and 12-17 Oct. Geomagnetic field activity is expected to reach active to G1 storm levels on 24-25 Sep due to positive polarity CH HSS effects. Unsettled to active levels are expected on 26-27 Sep and 04-08 Oct due to positive polarity CH HSS effects. Quiet to unsettled levels are expected on 11-14 Oct due to negative polarity CH HSS effects. Largely quiet levels are anticipated for all remaining dates in the forecast period.