Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 August 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 237 Issued at 2200Z on 25 Aug 2017

IA.  Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C5 event observed at 25/0727Z from Region 2672 (N07E05). There are currently 2 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one and two (26 Aug, 27 Aug) and expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on day three (28 Aug).

IIA.  Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 388 km/s at 25/0136Z. Total IMF reached 6 nT at 25/2047Z. The maximum southward component of Bz reached -4 nT at 25/1039Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 7705 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (26 Aug, 27 Aug) and quiet to unsettled levels on day three (28 Aug).

III.  Event probabilities 26 Aug-28 Aug
Class M    15/15/10
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           25 Aug 081
Predicted   26 Aug-28 Aug 081/080/078
90 Day Mean        25 Aug 076

V.  Geomagnetic A Indices
Observed Afr/Ap 24 Aug  016/014
Estimated Afr/Ap 25 Aug  006/008
Predicted Afr/Ap 26 Aug-28 Aug  005/005-005/005-007/008

VI.  Geomagnetic Activity Probabilities 26 Aug-28 Aug
A.  Middle Latitudes
Active                10/10/10
Minor Storm           01/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           15/15/15
Major-severe storm    15/15/15