Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 118 Issued at 2200Z on 28 Apr 2023
IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C6 event observed at 28/1600Z from Region 3289 (N20E37). There are currently 6 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (29 Apr, 30 Apr, 01 May).
IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at unsettled to active levels for the past 24 hours. Solar wind speed reached a peak of 740 km/s at 28/1322Z. Total IMF reached 5 nT at 28/0751Z. The maximum southward component of Bz reached -5 nT at 27/2255Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 5965 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (29 Apr, 30 Apr) and quiet to unsettled levels on day three (01 May).
III. Event probabilities 29 Apr-01 May
Class M 25/25/25
Class X 01/01/01
Proton 05/05/05
PCAF green
IV. Penticton 10.7 cm Flux
Observed 28 Apr 150
Predicted 29 Apr-01 May 145/145/145
90 Day Mean 28 Apr 158
V. Geomagnetic A Indices
Observed Afr/Ap 27 Apr 020/025
Estimated Afr/Ap 28 Apr 018/022
Predicted Afr/Ap 29 Apr-01 May 013/016-010/012-008/012
VI. Geomagnetic Activity Probabilities 29 Apr-01 May
A. Middle Latitudes
Active 25/25/15
Minor Storm 10/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/15
Major-severe storm 20/30/15
space weather
