- Press Release
- Dec 2, 2022
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 September 2017
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 266 Issued at 2200Z on 23 Sep 2017
IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 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 (24 Sep, 25 Sep, 26 Sep).
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 410 km/s at 23/0904Z. Total IMF reached 5 nT at 23/0052Z. The maximum southward component of Bz reached -4 nT at 23/0343Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2143 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (24 Sep, 25 Sep) and quiet to unsettled levels on day three (26 Sep).
III. Event probabilities 24 Sep-26 Sep
Class M 15/15/15
Class X 01/01/01
IV. Penticton 10.7 cm Flux
Observed 23 Sep 081
Predicted 24 Sep-26 Sep 085/090/090
90 Day Mean 23 Sep 081
V. Geomagnetic A Indices
Observed Afr/Ap 22 Sep 005/004
Estimated Afr/Ap 23 Sep 004/005
Predicted Afr/Ap 24 Sep-26 Sep 009/012-014/016-008/008
VI. Geomagnetic Activity Probabilities 24 Sep-26 Sep
A. Middle Latitudes
Minor Storm 10/15/05
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 25/25/25
Major-severe storm 40/50/25