Solar activity has been at moderate levels for the past 24 hours. Region 1521 (S21W47) produced an M1/1f x-ray event at 0458Z. As well as being partially responsible for todays M-class flare, Region 1520 (S17W35) also produced a C2/Sf event at 1410Z with an associated 150 sfu Tenflare. Elsewhere on the solar disk, Region 1519 (S16W56) and Region 1523 (S28E04) grew both in area and magnetic complexity, however, both have remained quiet and stable. No Earth directed CMEs were observed.

Solar activity is expected to be at low to moderate levels for the next three days (15-17 July) as Region 1520 and Region 1521 continue to evolve.

The geomagnetic field began the period at quiet levels until around 1811Z, when a sudden impulse of 27 nT was observed by the Boulder magnetometer. 43 minutes earlier, at 1728Z, measurements made by the ACE spacecraft indicated a shock arrival. Solar wind speeds increased from 350 km/s to around 630 km/s and the IMF (total field) increased from 4 nT to around 17 nT, with extended periods of the Bz component hovering around -12 nT. All of these signatures are congruent with the arrival of a CME at ACE and later here at Earth. After the arrival of the CME, an increase from quiet to minor storm levels was observed. A greater than 10 MeV proton event began, reached a peak of 96 pfu at 12/2225Z, and is still in progress. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period.

The geomagnetic field is expected to be at quiet to active levels with a slight chance for minor storms on day one (15 July), as CME effects continue. Predominantly quiet levels are expected on days two and three (16-17 July).

  Observé       14 Jul 148
  Prévisionnel   15 Jul-17 Jul  140/130/120
  Moyenne des 90 derniers jours        14 Jul 128

  Observé Afr/Ap 13 Jul  004/003
  Estimé     Afr/Ap 14 Jul  010/018
  Prévisionnel    Afr/Ap 15 Jul-17 Jul  015/022-007/008-006/005