FXXX12 KWNP 200031 DAYDIS :Product: Forecast Discussion :Issued: 2026 Mar 20 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. Region 4392 (S17W26, Csi/beta-gamma) was the sole contributor for flare activity, with the largest being a C2.3/Sf at 19/0558 UTC. Continued consolidation and decay was observed from this region during the period. Region 4397 (N17E55, Cao/beta) remained unchaned and stable. Regions 4391 (N07, L=067) and 4395 (S06, L=006) fully decayed to plage. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be very low, with C-class flares likely, on 20-22 Mar due primarily to the minor instability and variability of Region 4392. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels, with a peak of 4,941 pfu at 19/1710 UTC. The greater than 10 MeV proton flux continued at background levels. .Forecast... The greater than 2 MeV electron flux is likely to decrease to normal-moderate levels on 20-22 Mar, due to anticipated CME arrivals. The greater than 10 MeV proton flux is expected to continue at background values. Solar Wind .24 hr Summary... Solar wind parameters reflected near background conditions for most of the period. Total IMF strength averaged near 4 nT, Bz was predominantly northward, and solar wind speed continued to decrease from 400 km/s to end the period near 350 km/s. The phi angle was predominantly positive. At approximately 19/1930 UTC, solar wind speed increased slightly from ~337 km/s to 377 km/s while the Phi angle simultaneously rotated from a positive orientation to a negative position. .Forecast... The solar wind environment is expected to become enhanced on 20 Mar as the 16-17 Mar CMEs are still anticipated to at least graze the Earth. By 21 Mar, the CME from 18 Mar is expected to have a more direct impact at Earth, in conjunction with the onset of a negative polarity CH HSS. Elevated parameters are expected to continue through 22 Mar as CME/CH HSS effects persist. Geospace .24 hr Summary... The geomagnetic field was quiet. .Forecast... The geomagnetic field is expected to be at active to G2 (Moderate) storm levels on 20 Mar as CMEs from 16-17 Mar are anticipated to arrive. Additional G2 (Moderate) storm conditions are likely, with G3 (Strong) conditions possible, on 21 Mar as the CME from 18 Mar is expected to arrive in conjunction with the onset of a negative polarity CH HSS. Unsettled to G1 (Minor) levels are expected on 22 Mar as CME/CH HSS effects persist.