Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 229 Issued at 2200Z on 17 Aug 2023
IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C5 event observed at 17/1240Z from Region 3397 (N17W83). There are currently 9 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 (18 Aug, 19 Aug, 20 Aug).
IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 348 km/s at 17/1627Z. Total IMF reached 11 nT at 17/2030Z. The maximum southward component of Bz reached -6 nT at 17/1533Z.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (18 Aug), quiet to unsettled levels on day two (19 Aug) and quiet levels on day three (20 Aug).
III. Event probabilities 18 Aug-20 Aug
Class M 15/15/15
Class X 05/05/05
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 17 Aug 152
Predicted 18 Aug-20 Aug 150/155/157
90 Day Mean 17 Aug 167
V. Geomagnetic A Indices
Observed Afr/Ap 16 Aug 010/012
Estimated Afr/Ap 17 Aug 009/010
Predicted Afr/Ap 18 Aug-20 Aug 010/012-007/008-006/005
VI. Geomagnetic Activity Probabilities 18 Aug-20 Aug
A. Middle Latitudes
Active 20/15/10
Minor Storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/15
Major-severe storm 20/20/10
space weather
