Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 112 Issued at 2200Z on 22 Apr 2023
IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C4 event observed at 22/0148Z from Region 3279 (S19W64). 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 (23 Apr, 24 Apr, 25 Apr).
IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 457 km/s at 22/1152Z. Total IMF reached 6 nT at 21/2100Z. The maximum southward component of Bz reached -5 nT at 21/2113Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 2 pfu at 22/2010Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 143 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (23 Apr), unsettled to major storm levels on day two (24 Apr) and quiet to active levels on day three (25 Apr). Protons have a slight chance of crossing threshold on days one, two, and three (23 Apr, 24 Apr, 25 Apr).
III. Event probabilities 23 Apr-25 Apr
Class M 35/35/35
Class X 01/01/01
Proton 15/15/15
PCAF green
IV. Penticton 10.7 cm Flux
Observed 22 Apr 141
Predicted 23 Apr-25 Apr 140/135/135
90 Day Mean 22 Apr 159
V. Geomagnetic A Indices
Observed Afr/Ap 21 Apr 008/009
Estimated Afr/Ap 22 Apr 007/008
Predicted Afr/Ap 23 Apr-25 Apr 009/013-026/038-013/015
VI. Geomagnetic Activity Probabilities 23 Apr-25 Apr
A. Middle Latitudes
Active 40/25/30
Minor Storm 30/35/15
Major-severe storm 10/35/01
B. High Latitudes
Active 15/05/15
Minor Storm 20/20/30
Major-severe storm 20/79/45
space weather
