Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 128 Issued at 2200Z on 08 May 2023
IA. Analysis of Solar Active Regions and Activity from 07/2100Z to 08/2100Z: 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 07/2323Z from Region 3296 (N16W06). There are currently 5 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 days one, two, and three (09 May, 10 May, 11 May).
IIA. Geophysical Activity Summary 07/2100Z to 08/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 551 km/s at 08/1552Z. Total IMF reached 15 nT at 07/2101Z. The maximum southward component of Bz reached -13 nT at 07/2345Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 23 pfu at 08/1825Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 137 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on days one and two (09 May, 10 May) and unsettled to minor storm levels on day three (11 May). Protons are expected to cross threshold on day one (09 May), have a chance of crossing threshold on day two (10 May) and have a slight chance of crossing threshold on day three (11 May).
III. Event probabilities 09 May-11 May
Class M 55/55/55
Class X 20/20/20
Proton 95/50/20
PCAF yellow
IV. Penticton 10.7 cm Flux
Observed 08 May 172
Predicted 09 May-11 May 170/170/170
90 Day Mean 08 May 159
V. Geomagnetic A Indices
Observed Afr/Ap 07 May 008/010
Estimated Afr/Ap 08 May 017/027
Predicted Afr/Ap 09 May-11 May 013/014-012/018-024/032
VI. Geomagnetic Activity Probabilities 09 May-11 May
A. Middle Latitudes
Active 40/35/35
Minor Storm 25/25/25
Major-severe storm 05/10/10
B. High Latitudes
Active 15/15/10
Minor Storm 30/20/20
Major-severe storm 45/30/45
