Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 August 2015
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 240 Issued at 2200Z on 28 Aug 2015
IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M2 event observed at 28/1316Z from Region 2403 (S15W69). 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 and two (29 Aug, 30 Aug) and expected to be low with a chance for M-class flares on day three (31 Aug).
IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at unsettled to major storm levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 440 km/s at 28/1841Z. Total IMF reached 17 nT at 28/1801Z. The maximum southward component of Bz reached -16 nT at 28/1708Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 256 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (29 Aug), quiet to active levels on day two (30 Aug) and quiet to unsettled levels on day three (31 Aug). Protons greater than 10 Mev have a slight chance of crossing threshold on days one and two (29 Aug, 30 Aug).
III. Event probabilities 29 Aug-31 Aug
Class M 60/60/50
Class X 10/10/05
Proton 10/10/05
PCAF green
IV. Penticton 10.7 cm Flux
Observed 28 Aug 109
Predicted 29 Aug-31 Aug 110/105/100
90 Day Mean 28 Aug 112
V. Geomagnetic A Indices
Observed Afr/Ap 27 Aug 026/051
Estimated Afr/Ap 28 Aug 033/048
Predicted Afr/Ap 29 Aug-31 Aug 019/025-010/012-009/008
VI. Geomagnetic Activity Probabilities 29 Aug-31 Aug
A. Middle Latitudes
Active 40/30/15
Minor Storm 25/10/05
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 25/30/25
Major-severe storm 60/40/25
