- Nov 13, 2023
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 266 Issued at 2200Z on 23 Sep 2023
IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 22/2300Z from Region 3443 (N28W40). There are currently 12 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, 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 to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 395 km/s at 23/0034Z. Total IMF reached 5 nT at 23/1008Z. The maximum southward component of Bz reached -5 nT at 23/1717Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2394 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (24 Sep) and quiet to active levels on days two and three (25 Sep, 26 Sep). Protons have a slight chance of crossing threshold on days one, two, and three (24 Sep, 25 Sep, 26 Sep).
III. Event probabilities 24 Sep-26 Sep
Class M 60/60/60
Class X 15/15/15
IV. Penticton 10.7 cm Flux
Observed 23 Sep 173
Predicted 24 Sep-26 Sep 175/172/168
90 Day Mean 23 Sep 162
V. Geomagnetic A Indices
Observed Afr/Ap 22 Sep 007/010
Estimated Afr/Ap 23 Sep 010/010
Predicted Afr/Ap 24 Sep-26 Sep 018/022-013/015-009/012
VI. Geomagnetic Activity Probabilities 24 Sep-26 Sep
A. Middle Latitudes
Minor Storm 20/05/05
Major-severe storm 05/01/01
B. High Latitudes
Minor Storm 20/20/20
Major-severe storm 30/25/20