- Press Release
- Sep 24, 2023
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 256 Issued at 2200Z on 13 Sep 2023
IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C5 event observed at 12/2200Z from Region 3423 (N16W44). There are currently 6 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 (14 Sep, 15 Sep, 16 Sep).
IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 442 km/s at 13/0358Z. Total IMF reached 15 nT at 12/2345Z. The maximum southward component of Bz reached -10 nT at 12/2308Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 121 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (14 Sep, 15 Sep) and quiet levels on day three (16 Sep).
III. Event probabilities 14 Sep-16 Sep
Class M 40/40/35
Class X 05/05/05
IV. Penticton 10.7 cm Flux
Observed 13 Sep 143
Predicted 14 Sep-16 Sep 145/145/148
90 Day Mean 13 Sep 163
V. Geomagnetic A Indices
Observed Afr/Ap 12 Sep 017/025
Estimated Afr/Ap 13 Sep 015/018
Predicted Afr/Ap 14 Sep-16 Sep 012/012-013/015-007/008
VI. Geomagnetic Activity Probabilities 14 Sep-16 Sep
A. Middle Latitudes
Minor Storm 05/15/05
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 20/30/20
Major-severe storm 20/30/20