Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 255 Issued at 2200Z on 12 Sep 2023
IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M2 event observed at 12/0707Z from Region 3423 (N16W44). There are currently 8 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 (13 Sep, 14 Sep, 15 Sep).
IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field has been at quiet to major storm levels for the past 24 hours. Solar wind speed reached a peak of 429 km/s at 12/1249Z. Total IMF reached 20 nT at 12/1350Z. The maximum southward component of Bz reached -19 nT at 12/1419Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 328 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (13 Sep) and quiet to active levels on days two and three (14 Sep, 15 Sep). Protons greater than 10 Mev have a slight chance of crossing threshold on days two and three (14 Sep, 15 Sep).
III. Event probabilities 13 Sep-15 Sep
Class M 55/55/55
Class X 10/10/10
Proton 05/10/10
PCAF green
IV. Penticton 10.7 cm Flux
Observed 12 Sep 154
Predicted 13 Sep-15 Sep 160/155/152
90 Day Mean 12 Sep 163
V. Geomagnetic A Indices
Observed Afr/Ap 11 Sep 008/007
Estimated Afr/Ap 12 Sep 020/032
Predicted Afr/Ap 13 Sep-15 Sep 015/016-012/012-013/015
VI. Geomagnetic Activity Probabilities 13 Sep-15 Sep
A. Middle Latitudes
Active 35/20/35
Minor Storm 15/05/15
Major-severe storm 01/01/01
B. High Latitudes
Active 20/15/20
Minor Storm 30/20/30
Major-severe storm 30/20/30
Space weather
