Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 216 Issued at 2200Z on 04 Aug 2023

IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: 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 04/0424Z from Region 3386 (N11W62). There are currently 9 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 day one (05 Aug) and expected to be low with a chance for M-class flares on days two and three (06 Aug, 07 Aug).

IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 494 km/s at 04/0620Z. Total IMF reached 16 nT at 04/0824Z. The maximum southward component of Bz reached -12 nT at 04/1635Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (05 Aug) and quiet to active levels on days two and three (06 Aug, 07 Aug). Protons greater than 10 Mev have a slight chance of crossing threshold on day one (05 Aug).

III. Event probabilities 05 Aug-07 Aug
Class M 55/35/35
Class X 10/05/05
Proton 10/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 04 Aug 171
Predicted 05 Aug-07 Aug 165/162/164
90 Day Mean 04 Aug 166

V. Geomagnetic A Indices
Observed Afr/Ap 03 Aug NA/008
Estimated Afr/Ap 04 Aug 010/015
Predicted Afr/Ap 05 Aug-07 Aug 020/028-013/015-009/012

VI. Geomagnetic Activity Probabilities 05 Aug-07 Aug
A. Middle Latitudes
Active 35/35/20
Minor Storm 30/15/05
Major-severe storm 10/01/01
B. High Latitudes
Active 15/20/15
Minor Storm 25/30/20
Major-severe storm 50/30/20

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