Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 151 Issued at 2200Z on 31 May 2023
IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: 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 31/0438Z from Region 3323 (S05E68). There are currently 10 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days one, two, and three (01 Jun, 02 Jun, 03 Jun).
IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 432 km/s at 30/2121Z. Total IMF reached 8 nT at 31/2039Z. The maximum southward component of Bz reached -8 nT at 31/1947Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 653 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (01 Jun), quiet to minor storm levels on day two (02 Jun) and quiet to active levels on day three (03 Jun). Protons have a slight chance of crossing threshold on days one, two, and three (01 Jun, 02 Jun, 03 Jun).
III. Event probabilities 01 Jun-03 Jun
Class M 40/40/40
Class X 10/10/10
Proton 10/10/10
PCAF green
IV. Penticton 10.7 cm Flux
Observed 31 May 161
Predicted 01 Jun-03 Jun 160/160/150
90 Day Mean 31 May 153
V. Geomagnetic A Indices
Observed Afr/Ap 30 May 006/005
Estimated Afr/Ap 31 May 006/005
Predicted Afr/Ap 01 Jun-03 Jun 006/005-010/015-010/012
VI. Geomagnetic Activity Probabilities 01 Jun-03 Jun
A. Middle Latitudes
Active 10/40/30
Minor Storm 05/25/15
Major-severe storm 01/05/01
B. High Latitudes
Active 15/10/15
Minor Storm 20/25/20
Major-severe storm 15/65/20
space weather
