:Product: 04171230forecast_discussion.txt :Issued: 2014 Apr 17 1230 UTC # Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center # Solar Activity .24 hr Summary... Solar activity was at moderate levels. Region 2035 (S14E03, Fsc/beta-gamma) produced a M1/1N solar flare (NOAA Scale R1 - minor radio blackout) at 16/1959 UTC with an associated type II radio sweep (estimated speed 1071 km/s). Based on limited SOHO LASCO C2/C3 coronagraph and STEREO A and B images, initial analysis indicated an Earth-directed coronal mass ejection (CME) with a preliminary speed of 642 km/s. Current Enlil run indicates a potential arrival at Earth on 19 April at approximately 1800 UTC. Additional analysis will be accomplished with possible adjustments to timing of arrival times as additional data becomes available. Origins of the previous Type II and Type IV sweeps could not be determined due to a data gap at that time, though Region 2035 is a likely suspect. Region 2034 (N05W19, Dsc/beta) exhibited moderate growth in its intermediate spots. Region 2036 (S15W21, Dac/beta-gamma) continued to show growth in areal coverage as well as exhibiting continued mixing in its intermediate spot area. New Region 2042 also showed growth as it rotated further on to the visible disk, though limb proximity inhibited accurate magnetic analysis. Region 2038 (S13E44, Cso/beta) and Region 2039 (N25W10, Bxo/beta) both exhibited slight growth during the period as well. The remaining spot groups were either stable or exhibited slight decay. .Forecast... Solar activity is likely to be moderate (R1-Minor) for the next three days (17 - 19 Apr) due to solar region complexity and growth. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit was at moderate levels through 16/2335 UTC, then dropped to normal levels where it remained for the remainder of the period. The greater than 10 MeV proton flux at geosynchronous orbit was at background levels. .Forecast... The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal levels for the next three days (17 - 19 Apr). The greater than 10 MeV proton flux at geosynchronous orbit is expected to be at background levels (Below S1-Minor) during the period. Solar Wind .24 hr Summary... Solar wind parameters, measured at the ACE spacecraft, were near background conditions through approximately 16/2000 UTC. Solar wind speed remained steady near 300 km/s, IMF Bt was steady at 3 nT while the Bz component remained at -2 nT. Shortly before 2000 UTC, IMF total field showed a slight increase to 6 nT with Bz dropping to -6 nT. Phi angle was oscillating between negative (toward) and positive (away) for the first half of the period as well. Just before the new UT day began, the IMF total field again saw a slight increase to 9 nT, with Bz seeing a maximum deflection near -8 nT. Wind speed also increase around this time to approximately 350 km/s. Wind speeds continued a slow but steady increase through the end of the period, finishing at approximately 390 km/s. Both IMF Bt and Bz remained variable through the end of the period while the Phi angle settled into a positive (away) orientation. .Forecast... Solar wind enhancements, including modest speed and Bt increases, are expected on days one and two (17 - 18 Apr) due to possible recurrent activity. A return to nominal conditions is expected by day three (19 Apr). Geospace .24 hr Summary... The geomagnetic field was quiet to unsettled. .Forecast... The geomagnetic field is expected to be mostly quiet with isolated unsettled periods for days one and two (17 - 18 Apr) in response to possible recurrent enhancements in solar wind parameters. The field should return to mostly quiet levels on day three (19 Apr).