:Product: Weekly Highlights and Forecasts :Issued: 2026 May 11 0150 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 # # Weekly Highlights and Forecasts # Highlights of Solar and Geomagnetic Activity 04 - 10 May 2026 Solar activity reached high levels on 10 May due to an M5.7/2b flare (R2-Moderate) at 10/1339UTC from Region 4436 (N19, L=330, class/area=Dao/beta on 10 May), the strongest of the period. Associated with the event was a Type II radio sweep (est. 650 km/s), Tenflare (550sfu), and a CME signature first observed in coronagraph imagery at 10/1348UTC towards the NE. Analysis and modeling of the event is ongoing at the time of this writing. Region 4424 (N17, L=192, class/area=Eai/160 on 30 Apr) also produced an M-class event with an M1.8 flare (R1-Minor) observed at 04/0133 UTC. The other 10 numbered active regions on this visible disk were either mostly quiet or only produced C-class activity during the past week No proton events were observed at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels throughout the summary period. Geomagnetic field activity reached G2 (Moderate) geomagnetic storm levels on 04 May and G1 (Minor) levels on 05 May due to influence from a passing CME. Total magnetic field strength only reached a peak of 11 nT during that time but Bz rotated as far southward as -10 nT and was sustained southward from late on 04 May through midday on 05 May. Despite the influence of a positive polarity coronal hole beginning late on 07 May, the mostly northward Bz component results in only quiet to unsettled conditions through the end of the reporting period. Forecast of Solar and Geomagnetic Activity 11 May - 06 June 2026 Solar activity is expected to be at low levels, with a chance for M-class activity (R1/R2-Minor/Moderate), and a slight chance for X-class (R3-Strong), throughout the outlook period due to the flare potential of several active regions both currently on the visible disk and those expected to return from the Sun's farside. 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 17-20 May due to influence from a recurrent, negative polarity coronal hole. The remainder of the outlook period is likely to be at normal to moderate levels. Geomagnetic field activity is likely to reach G1 (Minor) geomagnetic storm levels over 15-17 May; active conditions are likely on 18 May, 23 May, 27 May, and 03 Jun; unsettled conditions are likely over 11 May, 13 May, 21-22 May, and 28 May - 31 May. All enhancements in geomagnetic activity are due to the anticipated influence of multiple, recurrent, coronal hole HSSs. The remainder of the outlook period is likely to be at mostly quiet levels.