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Here is the current forecast discussion on space weather and geophysical activity, issued 2016 Apr 18 1230 UTC.
Solar Activity
24 hr Summary: Solar activity reached high levels due to an M6/1f flare (R2-Moderate) observed at 18/0029 UTC from Region 2529 (N10W59, Cko/beta). Associated with this event were Type II (estimated 1869 km/s shock velocity), Type IV and 10 cm (120 sfu) radio emissions. LASCO C2/C3 and STEREO-A imagery observed a CME off the west limb, first visible at 18/0036 UTC. Initial analysis and subsequent WSA-Enlil output suggests a possible glancing blow mid to late on 20 April. Further analysis is pending additional imagery.
Region 2529 continued its dissipation of intermediate and trailer spots. Region 2532 (N06E46, Cso/beta) developed small new intermediate and leader spots early in the period, but have since dissipated. The remainder of the disk and limb was quiet and stable. No other Earth-directed CMEs were observed in available coronagraph imagery.
Forecast: Solar activity is expected to continue at low levels with a slight chance for M-class flare activity (R1-Minor to R2-Moderate) over the next two days (18-19 Apr). Very low activity is expected on day three (20 Apr), with a slight chance for C-class flares, as Region 2529 rotates off the visible disk.
Energetic Particles
24 hr Summary: The greater than 2 MeV electron flux reached high levels with a maximum flux of 1,040 pfu observed at 17/1635 UTC. The greater than 10 MeV proton flux remained at background levels.
Forecast: The greater than 2 MeV electron flux is expected to be at normal to moderate levels for the duration of the forecast period (18-20 Apr). The greater than 10 MeV proton flux is expected to remain at background levels.
Solar Wind
24 hr Summary: Solar wind parameters, as measured by the ACE spacecraft, reflected slightly enhanced conditions. Total field ranged between 1-13 nT while the Bz component varied between -6 nT to +9 nT. Solar wind speeds began the period at 400 km/s and slowly decreased to end the period near 370 km/s. The phi angle was weakly negative through about 18/0130 UTC when it rotated positive through 18/0800 UTC. After that, Phi was highly variable.
Forecast: Enhanced solar wind conditions are expected later on day one (18 Apr) with an anticipated CIR ahead of a positive polarity CH HSS. Enhancements are expected to continue on day two (19 Apr) with CH HSS effects waning by day three (20 Apr).
Geospace
24 hr Summary: The geomagnetic field was at quiet to active levels due to a sustained southward Bz component.
Forecast: The geomagnetic field is expected to be mostly quiet to unsettled with isolated periods of active conditions on day one (18 Apr) in response to the influence of a positive polarity CH HSS becoming geoeffective. Active conditions are likely to continue on day two (19 Apr) as the CH HSS persists. Mostly quiet conditions, with isolated periods of unsettled, are likely on day three (20 Apr) as the CH HSS subsides.
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![Today's Space Weather Forecast Discussion - 2016 Apr 18 20:07 UTC]()
Live data: SunSpotWatch.com
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