Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 August 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 233 Issued at 2200Z on 21 Aug 2015

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 21/0948Z from Region 2403 (S14E23). There are currently 3 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days one, two, and three (22 Aug, 23 Aug, 24 Aug).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 558 km/s at 21/0106Z. Total IMF reached 6 nT at 20/2151Z. The maximum southward component of Bz reached -5 nT at 20/2118Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 9116 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (22 Aug), unsettled to minor storm levels on day two (23 Aug) and quiet to active levels on day three (24 Aug).

III. Event probabilities 22 Aug-24 Aug
Class M 35/35/35
Class X 10/10/10
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 Aug 110
Predicted 22 Aug-24 Aug 110/110/115
90 Day Mean 21 Aug 110

V. Geomagnetic A Indices
Observed Afr/Ap 20 Aug 011/014
Estimated Afr/Ap 21 Aug 006/008
Predicted Afr/Ap 22 Aug-24 Aug 007/008-021/028-011/012

VI. Geomagnetic Activity Probabilities 22 Aug-24 Aug
A. Middle Latitudes
Active 10/45/30
Minor Storm 05/25/05
Major-severe storm 01/05/01
B. High Latitudes
Active 15/05/15
Minor Storm 15/25/30
Major-severe storm 15/70/40