Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 261 Issued at 2200Z on 18 Sep 2022

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at low levels for the past 24 hours.

The largest solar event of the period was a C3 event observed at 18/1540Z from Region 3100 (S22W60). There are currently 2 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 (19 Sep, 20 Sep, 21 Sep).

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 550 km/s at 18/2013Z. Total IMF reached 12 nT at 18/0911Z. The maximum southward component of Bz reached -9 nT at 18/1149Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 2 pfu at 18/0215Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 614 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (19 Sep) and quiet levels on days two and three (20 Sep, 21 Sep).

III. Event probabilities 19 Sep-21 Sep
Class M 20/20/20
Class X 05/05/05
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 Sep 136
Predicted 19 Sep-21 Sep 138/135/135
90 Day Mean 18 Sep 123

V. Geomagnetic A Indices
Observed Afr/Ap 17 Sep 005/004
Estimated Afr/Ap 18 Sep 011/012
Predicted Afr/Ap 19 Sep-21 Sep 010/010-005/005-005/005

VI. Geomagnetic Activity Probabilities 19 Sep-21 Sep
A. Middle Latitudes
Active 15/15/15
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 15/15/15
Major-severe storm 10/10/10

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