Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 31 Issued at 2200Z on 31 Jan 2023

IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at low levels for the past 24 hours.

The largest solar event of the period was a C4 event observed at 31/1100Z from Region 3207 (S11E65). There are currently 5 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on days one, two, and three (01 Feb, 02 Feb, 03 Feb).

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 528 km/s at 31/1341Z. Total IMF reached 8 nT at 31/0018Z. The maximum southward component of Bz reached -6 nT at 31/1622Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 473 pfu.

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

III. Event probabilities 01 Feb-03 Feb
Class M 15/15/15
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 31 Jan 137
Predicted 01 Feb-03 Feb 135/140/140
90 Day Mean 31 Jan 152

V. Geomagnetic A Indices
Observed Afr/Ap 30 Jan 004/004
Estimated Afr/Ap 31 Jan 010/012
Predicted Afr/Ap 01 Feb-03 Feb 007/008-006/005-006/005

VI. Geomagnetic Activity Probabilities 01 Feb-03 Feb
A. Middle Latitudes
Active 30/20/10
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/20/15
Minor Storm 30/25/20
Major-severe storm 40/25/10

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