- Nov 13, 2023
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 271 Issued at 2200Z on 28 Sep 2023
IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: 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 28/0907Z from Region 3450 (S19E58). There are currently 7 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (29 Sep, 30 Sep, 01 Oct).
IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 479 km/s at 28/0135Z. Total IMF reached 8 nT at 28/2054Z. The maximum southward component of Bz reached -4 nT at 28/0236Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1186 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (29 Sep), quiet to active levels on day two (30 Sep) and quiet to unsettled levels on day three (01 Oct).
III. Event probabilities 29 Sep-01 Oct
Class M 30/30/30
Class X 01/01/01
IV. Penticton 10.7 cm Flux
Observed 28 Sep 148
Predicted 29 Sep-01 Oct 148/148/145
90 Day Mean 28 Sep 162
V. Geomagnetic A Indices
Observed Afr/Ap 27 Sep 012/015
Estimated Afr/Ap 28 Sep 006/006
Predicted Afr/Ap 29 Sep-01 Oct 005/005-010/012-008/008
VI. Geomagnetic Activity Probabilities 29 Sep-01 Oct
A. Middle Latitudes
Minor Storm 01/10/05
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 15/30/25
Major-severe storm 10/40/25