- Press Release
- Nov 26, 2022
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 September 2017
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 268 Issued at 2200Z on 25 Sep 2017
IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 3 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (26 Sep, 27 Sep, 28 Sep).
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 reached a peak of 455 km/s at 25/0758Z. Total IMF reached 10 nT at 24/2216Z. The maximum southward component of Bz reached -9 nT at 24/2230Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1050 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (26 Sep), quiet to minor storm levels on day two (27 Sep) and active to major storm levels on day three (28 Sep).
III. Event probabilities 26 Sep-28 Sep
Class M 15/15/15
Class X 01/01/01
IV. Penticton 10.7 cm Flux
Observed 25 Sep 090
Predicted 26 Sep-28 Sep 095/095/095
90 Day Mean 25 Sep 082
V. Geomagnetic A Indices
Observed Afr/Ap 24 Sep 005/006
Estimated Afr/Ap 25 Sep 006/008
Predicted Afr/Ap 26 Sep-28 Sep 006/005-016/025-024/032
VI. Geomagnetic Activity Probabilities 26 Sep-28 Sep
A. Middle Latitudes
Minor Storm 05/30/40
Major-severe storm 01/05/10
B. High Latitudes
Minor Storm 25/20/20
Major-severe storm 25/65/80