Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 230 Issued at 2200Z on 18 Aug 2023
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 18/1930Z from Region 3409 (N20W42). There are currently 8 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 Aug, 20 Aug, 21 Aug).
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 553 km/s at 18/1246Z. Total IMF reached 14 nT at 18/0208Z. The maximum southward component of Bz reached -11 nT at 18/0723Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 157 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (19 Aug) and quiet to unsettled levels on days two and three (20 Aug, 21 Aug).
III. Event probabilities 19 Aug-21 Aug
Class M 20/20/20
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 18 Aug 150
Predicted 19 Aug-21 Aug 150/152/155
90 Day Mean 18 Aug 166
V. Geomagnetic A Indices
Observed Afr/Ap 17 Aug 010/007
Estimated Afr/Ap 18 Aug 010/011
Predicted Afr/Ap 19 Aug-21 Aug 010/010-008/008-006/008
VI. Geomagnetic Activity Probabilities 19 Aug-21 Aug
A. Middle Latitudes
Active 15/10/10
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/15/15
Major-severe storm 20/10/10
space weather
