Solar activity was moderate. Region 652 (N07W62) produced three M1 flares this period. Region 652 continues to slowly decay as it approaches the west limb. It still maintains considerable size and a complex delta configuration. No other significant changes were observed on the disk or limb.

Solar activity is expected to be moderate. Continued M-class activity is expected from Region 652 and there is a slight chance for a major flare.

The geomagnetic field ranged from unsettled to severe storming. A strong sudden impulse (SI) of 95 Nt was observed on the Boulder magnetometer at 26/2228Z. This SI followed the very fast (~31 hours) transit of the full halo CME associated with the long duration M1 flare on 25/1514Z. Solar wind speed increased from the already elevated levels near 600 km/s to over 1050 km/s. After approximately four hours of fluctuating between -15 and +15 nT, the IMF Bz rotated strong southward and ranged from -15 to -25 nT for about 15 hours. The fast solar wind speed and southward Bz combined to produce severe geomagnetic storm levels at all latitudes from 27/0000Z to 27/1500Z. Solar wind speed was still near 800 km/s by the end of the period and the disturbance had declined to minor storm levels. The greater than 10 MeV proton event that began on 25/1855Z is still in progress. A rapid, short-lived increase in the greater than 10 MeV protons to 2,090 pfu occurred with the shock passage. Protons quickly declined and were straddling the 10 pfu alert threshold by the end of the period. The greater than 2 MeV electrons at geosynchronous orbit were at high levels.

The geomagnetic field is expected to range from quiet to major storm levels. The most disturbed periods are expected during the first half of day one as the current major disturbance subsides. Mostly quiet to unsettled conditions are expected on 29 - 30 July.

  Observé       27 Jul 118
  Prévisionnel   28 Jul-30 Jul  110/105/090
  Moyenne des 90 derniers jours        27 Jul 106

  Observé Afr/Ap 26 Jul  026/031
  Estimé     Afr/Ap 27 Jul  120/180
  Prévisionnel    Afr/Ap 28 Jul-30 Jul  020/025-010/015-008/010