- Nov 13, 2023
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 267 Issued at 2200Z on 24 Sep 2023
IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M4 event observed at 24/0328Z from Region 3445 (S14E05). There are currently 10 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 (25 Sep, 26 Sep, 27 Sep).
IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field has been at quiet to major storm levels for the past 24 hours. Solar wind speed reached a peak of 492 km/s at 24/2000Z. Total IMF reached 27 nT at 24/2043Z. The maximum southward component of Bz reached -27 nT at 24/2043Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 2 pfu at 24/1500Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1024 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to major storm levels on day one (25 Sep), quiet to active levels on day two (26 Sep) and quiet levels on day three (27 Sep). Protons have a chance of crossing threshold on day one (25 Sep) and have a slight chance of crossing threshold on days two and three (26 Sep, 27 Sep).
III. Event probabilities 25 Sep-27 Sep
Class M 65/65/65
Class X 15/15/15
IV. Penticton 10.7 cm Flux
Observed 24 Sep 174
Predicted 25 Sep-27 Sep 172/168/164
90 Day Mean 24 Sep 162
V. Geomagnetic A Indices
Observed Afr/Ap 23 Sep 009/013
Estimated Afr/Ap 24 Sep 011/020
Predicted Afr/Ap 25 Sep-27 Sep 023/028-009/015-005/005
VI. Geomagnetic Activity Probabilities 25 Sep-27 Sep
A. Middle Latitudes
Minor Storm 35/05/05
Major-severe storm 15/01/01
B. High Latitudes
Minor Storm 20/20/15
Major-severe storm 35/20/15