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Here is the current forecast discussion on space weather and geophysical activity, issued 2015 Dec 13 1230 UTC.
Solar Activity
24 hr Summary: Solar activity remained at low levels. Region 2470 (N13E70, Hsx/alpha) remained stable, but was responsible for the largest event of the period; a C7 x-ray event observed at 12/1346 UTC.
Additional low-level C-class activity was observed from Regions 2469 (S09W55, Cro/beta), 2465 (S05W11, Hax/alpha), 2466 (S13W41, Axx/alpha) and 2468 (S15E33, Dao/beta). The largest of these events was a C2 x-ray event observed at 12/1817 UTC from Region 2469. All of these regions exhibited little change during the period.
A long duration C5 x-ray event was observed associated with Region 2468 (S15E33, Dao/beta at 13/1034 UTC. Dimming can be observed around the region in SDO/AIA 193 imagery beginning at 13/1010 UTC. Once additional imagery becomes available, analysis will be conducted to determine if there is a potential Earth-directed CME from this event.
Forecast: Solar activity is expected to be at low levels with a chance for M-class flares (R1-R2/Minor-Moderate radio blackouts) all three days of the forecast period (13-15 Dec).
Energetic Particle
24 hr Summary: The greater than 2 MeV electron flux reached high levels again this period with a peak flux of 6,196 pfu at 12/1830 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 moderate to high levels all three days (13-15 Dec) due to coronal hole high speed stream (CH HSS) effects. The greater than 10 MeV proton flux is expected to continue at background levels.
Solar Wind
24 hr Summary: Solar wind parameters, measured at the ACE spacecraft, reflected waning coronal hole high speed stream (CH HSS) effects. Solar wind speed began the period at about 580 km/s and gradually decreased to near 500 km/s. Total IMF strength ranged from 2-5 nT while the Bz component ranged between +/- 3 nT. The phi angle remained in a predominately positive (away from Sun) sector during the period.
Forecast: A return to nominal conditions is expected on day one (13 Dec) and persist through day two (14 Dec). Late on 14 Dec, a solar sector boundary crossing (SSBC) is expected as the orientation moves from a positive (away from the Sun) to a negative (towards the Sun) sector. Early on day three (15 Dec), a co-rotating interaction region (CIR) in advance of a recurrent, negative polarity CH HSS will enhance solar wind parameters. STEREO A wind data suggests wind speeds could approach 650 km/s with this CH HSS.
Geospace
24 hr Summary: The geomagnetic field was at quiet to unsettled.
Forecast: The geomagnetic field is expected to be at predominately quiet to unsettled levels on days one and two (13-14 Dec) as CH HSS effects continue to wane. Isolated active periods are possible early on both days due to nighttime substorming. By day three (15 Dec), quiet to unsettled levels will increase to unsettled to active levels by midday due to a CIR in advance of a recurrent, negative polarity CH HSS.
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![Today's Space Weather Forecast Discussion - 2015 Dec 13 20:07 UTC]()
Live data: SunSpotWatch.com
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