Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 273 Issued at 2200Z on 30 Sep 2023

IA. Analysis of Solar Active Regions and Activity from 29/2100Z to 30/2100Z: 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 30/1635Z from Region 3451 (N14E60). 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 (01 Oct, 02 Oct, 03 Oct).

IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 532 km/s at 30/1031Z. Total IMF reached 6 nT at 29/2208Z. The maximum southward component of Bz reached -5 nT at 29/2246Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2212 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (01 Oct) and quiet to active levels on days two and three (02 Oct, 03 Oct).

III. Event probabilities 01 Oct-03 Oct
Class M 45/45/45
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 30 Sep 159
Predicted 01 Oct-03 Oct 156/154/154
90 Day Mean 30 Sep 162

V. Geomagnetic A Indices
Observed Afr/Ap 29 Sep 013/014
Estimated Afr/Ap 30 Sep 008/009
Predicted Afr/Ap 01 Oct-03 Oct 008/008-012/015-011/012

VI. Geomagnetic Activity Probabilities 01 Oct-03 Oct
A. Middle Latitudes
Active 20/40/30
Minor Storm 05/20/15
Major-severe storm 01/05/01
B. High Latitudes
Active 15/20/15
Minor Storm 25/30/20
Major-severe storm 25/35/30

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