Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 August 2015
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 237 Issued at 2200Z on 25 Aug 2015
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 C4 event observed at 25/0631Z from Region 2403 (S15W31). 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 (26 Aug, 27 Aug) and expected to be low with a chance for M-class flares on day three (28 Aug).
IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: 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 461 km/s at 25/0113Z. Total IMF reached 6 nT at 25/1707Z. The maximum southward component of Bz reached -5 nT at 25/1749Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1837 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (26 Aug), quiet to active levels on day two (27 Aug) and unsettled to active levels on day three (28 Aug). Protons greater than 10 Mev have a slight chance of crossing threshold on days one and two (26 Aug, 27 Aug).
III. Event probabilities 26 Aug-28 Aug
Class M 60/55/50
Class X 10/10/05
Proton 10/10/05
PCAF green
IV. Penticton 10.7 cm Flux
Observed 25 Aug 121
Predicted 26 Aug-28 Aug 120/125/125
90 Day Mean 25 Aug 112
V. Geomagnetic A Indices
Observed Afr/Ap 24 Aug 007/008
Estimated Afr/Ap 25 Aug 008/009
Predicted Afr/Ap 26 Aug-28 Aug 007/006-009/012-014/018
VI. Geomagnetic Activity Probabilities 26 Aug-28 Aug
A. Middle Latitudes
Active 20/30/35
Minor Storm 05/15/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/30/30
Major-severe storm 25/45/45
