Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 116 Issued at 2200Z on 26 Apr 2023
IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 26/1423Z from Region 3289 (N20E58). There are currently 6 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on days one, two, and three (27 Apr, 28 Apr, 29 Apr).
IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 611 km/s at 26/2009Z. Total IMF reached 10 nT at 26/1746Z. The maximum southward component of Bz reached -8 nT at 26/1810Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 4675 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to active levels on day one (27 Apr), quiet to minor storm levels on day two (28 Apr) and quiet to active levels on day three (29 Apr).
III. Event probabilities 27 Apr-29 Apr
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 26 Apr 137
Predicted 27 Apr-29 Apr 135/135/135
90 Day Mean 26 Apr 158
V. Geomagnetic A Indices
Observed Afr/Ap 25 Apr 007/008
Estimated Afr/Ap 26 Apr 011/013
Predicted Afr/Ap 27 Apr-29 Apr 015/018-019/025-013/015
VI. Geomagnetic Activity Probabilities 27 Apr-29 Apr
A. Middle Latitudes
Active 30/35/25
Minor Storm 15/20/10
Major-severe storm 01/05/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/20/20
Major-severe storm 40/30/20
space weather
