Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 113 Issued at 2200Z on 23 Apr 2017
IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 3 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 on days one, two, and three (24 Apr, 25 Apr, 26 Apr).
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at active to major storm levels for the past 24 hours. Solar wind speed reached a peak of 813 km/s at 23/2023Z. Total IMF reached 9 nT at 23/0406Z. The maximum southward component of Bz reached -7 nT at 23/0351Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 20544 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at active to minor storm levels on day one (24 Apr) and unsettled to minor storm levels on days two and three (25 Apr, 26 Apr).
III. Event probabilities 24 Apr-26 Apr Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green
IV. Penticton 10.7 cm Flux Observed 23 Apr 083 Predicted 24 Apr-26 Apr 084/084/084 90 Day Mean 23 Apr 078
V. Geomagnetic A Indices Observed Afr/Ap 22 Apr 037/061 Estimated Afr/Ap 23 Apr 030/044 Predicted Afr/Ap 24 Apr-26 Apr 023/030-015/020-015/020
VI. Geomagnetic Activity Probabilities 24 Apr-26 Apr A. Middle Latitudes Active 45/40/40 Minor Storm 25/25/25 Major-severe storm 01/01/01 B. High Latitudes Active 10/10/10 Minor Storm 25/25/25 Major-severe storm 65/60/60