Report of Solar Geophysical Activity

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 232 Issued at 2200Z on 20 Aug 2015

IA.  Analysis of Solar Active Regions and Activity from 19/2100Z to
20/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3 event observed at
20/0526Z from Region 2403 (S13E37). There are currently 3 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a slight chance for an M-class flare on days one, two, and three (21
Aug, 22 Aug, 23 Aug).

IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed, as measured by the ACE spacecraft, reached a peak speed of
566 km/s at 20/0813Z. Total IMF reached 7 nT at 20/1140Z. The maximum
southward component of Bz reached -6 nT at 20/1049Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 8392 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on days one and two (21 Aug, 22 Aug) and
unsettled to minor storm levels on day three (23 Aug).

III.  Event probabilities 21 Aug-23 Aug
Class M    15/15/15
Class X    05/05/05
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           20 Aug 103
Predicted   21 Aug-23 Aug 105/110/115
90 Day Mean        20 Aug 110

V.  Geomagnetic A Indices
Observed Afr/Ap 19 Aug  018/019
Estimated Afr/Ap 20 Aug  009/013
Predicted Afr/Ap 21 Aug-23 Aug  010/012-009/012-021/028

VI.  Geomagnetic Activity Probabilities 21 Aug-23 Aug
A.  Middle Latitudes
Active                30/25/45
Minor Storm           05/05/25
Major-severe storm    01/01/05
B.  High Latitudes
Active                15/20/05
Minor Storm           35/35/25
Major-severe storm    40/30/70