- Press Release
- Jun 7, 2023
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 105 Issued at 2200Z on 15 Apr 2023
IA. Analysis of Solar Active Regions and Activity from 14/2100Z to 15/2100Z: 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 14/2327Z from Region 3282 (N11E52). There are currently 8 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 (16 Apr, 17 Apr, 18 Apr).
IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 433 km/s at 15/0910Z. Total IMF reached 7 nT at 15/0034Z. The maximum southward component of Bz reached -5 nT at 14/2107Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 142 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (16 Apr, 17 Apr) and quiet levels on day three (18 Apr).
III. Event probabilities 16 Apr-18 Apr
Class M 50/50/50
Class X 10/10/10
IV. Penticton 10.7 cm Flux
Observed 15 Apr 176
Predicted 16 Apr-18 Apr 180/178/168
90 Day Mean 15 Apr 164
V. Geomagnetic A Indices
Observed Afr/Ap 14 Apr 010/007
Estimated Afr/Ap 15 Apr 009/012
Predicted Afr/Ap 16 Apr-18 Apr 009/010-007/008-006/005
VI. Geomagnetic Activity Probabilities 16 Apr-18 Apr
A. Middle Latitudes
Minor Storm 10/05/05
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 25/25/20
Major-severe storm 35/30/15