Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 August 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 235 Issued at 2200Z on 23 Aug 2015

IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M3 event observed at 22/2124Z from Region 2403 (S15W04). There are currently 2 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be moderate with a slight chance for an X-class flare on days one, two, and three (24 Aug, 25 Aug, 26 Aug).

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to major storm levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 611 km/s at 23/1403Z. Total IMF reached 15 nT at 23/0740Z. The maximum southward component of Bz reached -12 nT at 23/0731Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 207 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (24 Aug) and quiet to active levels on days two and three (25 Aug, 26 Aug). Protons greater than 10 Mev have a slight chance of crossing threshold on days two and three (25 Aug, 26 Aug).

III. Event probabilities 24 Aug-26 Aug
Class M 55/55/55
Class X 10/10/10
Proton 05/10/10
PCAF green

IV. Penticton 10.7 cm Flux
Observed 23 Aug 133
Predicted 24 Aug-26 Aug 120/120/125
90 Day Mean 23 Aug 111

V. Geomagnetic A Indices
Observed Afr/Ap 22 Aug 008/008
Estimated Afr/Ap 23 Aug 025/032
Predicted Afr/Ap 24 Aug-26 Aug 020/028-014/020-010/012

VI. Geomagnetic Activity Probabilities 24 Aug-26 Aug
A. Middle Latitudes
Active 45/35/30
Minor Storm 25/15/05
Major-severe storm 05/01/01
B. High Latitudes
Active 05/10/15
Minor Storm 20/25/30
Major-severe storm 70/50/40