Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 27 August 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 239 Issued at 2200Z on 27 Aug 2017

IA.  Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C6 event observed at 27/1516Z from Region 2671 (N13W93). There are currently 1 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on days one, two, and three (28 Aug, 29 Aug, 30 Aug).

IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 399 km/s at 27/0705Z. Total IMF reached 9 nT at 27/1621Z. The maximum southward component of Bz reached -9 nT at 27/1645Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 8019 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and three (28 Aug, 30 Aug) and quiet to unsettled levels on day two (29 Aug).

III.  Event probabilities 28 Aug-30 Aug
Class M    10/10/10
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           27 Aug 078
Predicted   28 Aug-30 Aug 078/078/078
90 Day Mean        27 Aug 076

V.  Geomagnetic A Indices
Observed Afr/Ap 26 Aug  005/004
Estimated Afr/Ap 27 Aug  009/011
Predicted Afr/Ap 28 Aug-30 Aug  009/008-007/008-012/015

VI.  Geomagnetic Activity Probabilities 28 Aug-30 Aug
A.  Middle Latitudes
Active                10/10/30
Minor Storm           01/05/10
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           15/15/20
Major-severe storm    15/15/20