FXXX12 KWNP 160031 DAYDIS :Product: Forecast Discussion :Issued: 2026 Oct 16 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 remained at low levels, with the largest flare of the period being a C4.9 at 15/1555 UTC from Region 4551 (S15W06, Eki/beta-gamma-delta), which produced the majority of Xray flares observed this period. This region exhibited several areas of new flux emergence surrounding its leader spot. Region 4557 (N07E29, Dri/beta) showed growth over the second half of the period. (Regions 4554 (N07, L=76), 4556 (N03, L=64), and 4558 (S03, L=144) all decayed to plage this period. The remaining regions were either stable or in decay. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be at low levels through 18 Oct, with a chance (25%) for M-class flares (R1-R2, Minor-Moderate) and a slight chance for an X-class flare (R3-Strong) due mainly to the flare potential of Region 4551. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux was at normal to moderate levels, and the greater than 10 MeV proton flux was at background levels. .Forecast... The greater than 2 MeV electron flux is expected to be at high levels on 16 Oct, decreasing to normal-moderate on 17-18 Oct. There is a slight chance for an S1 (Minor) solar radiation storm through 18 Oct due to the flare potential of Region 4551. Solar Wind .24 hr Summary... Solar wind parameters were elevated under diminishing HSS activity. Total field (Bt) maintained an average of 5 nT, with a variable Bz (north-south) component that ranged from a brief southward deflection of -5 nT at 15/1213 UTC to 4 nT. Solar wind speeds gradually decreased from about 545 km/s to end the period at about 440 km/s. Phi was largely negative. .Forecast... Solar wind conditions are anticipated to see an occasional isolated interval of disturbed/elevated conditions on 16 Oct as influences from a negative polarity CH HSS slowly wane, with a return to near-background/ambient levels on 17-18 Oct. Geospace .24 hr Summary... The geomagnetic field was at quiet to unsettled levels. .Forecast... Unsettled conditions are expected to persist through 16 Oct, as influences from the negative polarity CH HSS wane. 17 Oct is anticipated to return to quiet geomagnetic conditions, persisting through 18 Oct.