Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 26 August 2015
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 238 Issued at 2200Z on 26 Aug 2015
IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C9 event observed at 26/1353Z from Region 2403 (S16W44). There are currently 1 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 (27 Aug, 28 Aug) and expected to be low with a chance for M-class flares on day three (29 Aug).
IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: 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 450 km/s at 26/0413Z. Total IMF reached 10 nT at 26/0837Z. The maximum southward component of Bz reached -9 nT at 26/1837Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 526 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (27 Aug), unsettled to active levels on day two (28 Aug) and quiet to unsettled levels on day three (29 Aug). Protons greater than 10 Mev have a slight chance of crossing threshold on days one and two (27 Aug, 28 Aug).
III. Event probabilities 27 Aug-29 Aug
Class M 60/55/50
Class X 10/10/05
Proton 10/10/05
PCAF green
IV. Penticton 10.7 cm Flux
Observed 26 Aug 126
Predicted 27 Aug-29 Aug 125/125/120
90 Day Mean 26 Aug 112
V. Geomagnetic A Indices
Observed Afr/Ap 25 Aug 008/010
Estimated Afr/Ap 26 Aug 020/028
Predicted Afr/Ap 27 Aug-29 Aug 016/016-013/018-011/012
VI. Geomagnetic Activity Probabilities 27 Aug-29 Aug
A. Middle Latitudes
Active 40/30/25
Minor Storm 30/10/05
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 20/30/30
Major-severe storm 65/40/30
