Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
624 FXXX12 KWNP 181231 DAYDIS :Product: Forecast Discussion :Issued: 2025 Apr 18 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 low levels. The largest flare was a C4.6 at 17/1422 UTC from Region 4064 (N11E53, Dai/beta). Slight growth was observed in Region 4064. Slight growth and separation was observed in the larger leading spots of Region 4062 (S03E31, Dki/beta-gamma). The trailing spots E of Region 4062 were determined to be a separate spot group and was numbered Region 4066 (S05E42, Cai/beta). New Region 4067 (S02E60, Cao/beta) rotated onto the disk and was numbered but was inactive. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be low with a chance of M-class flares (R1-R2, Minor-Moderate) and a slight chance for X-class flares (R3, Strong) on 18-20 Apr. 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 likely to rebound following the passing of the CME. Moderate to high levels are likely on 18-20 Apr. The greater than 10 MeV proton flux is expected to continue at background levels. Solar Wind .24 hr Summary... Solar wind parameters were indicative of waning CME influence. Total field decreased from 13 nT to near 5 nT. The Bz component was mostly positive between +12/-1 nT. Solar wind speed averaged about 450 km/s. Phi angle became mostly negative after 17/1640 UTC. .Forecast... Solar wind parameters are expected to continue to be mildly elevated on 18 Apr as waning CME effects transition into a negative polarity CH HSS. HSS effects are expected to persist into 19 Apr and diminish by 20 Apr. Geospace .24 hr Summary... The geomagnetic field was quiet to active under waning CME effects. .Forecast... The geomagnetic field is expected to be at unsettled to active levels on 18 Apr as CME effects diminish with a likely transition into a negative polarity CH HSS. Quiet to unsettled levels are expected on 19-20 Apr.