Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 April 2018
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 110 Issued at 2200Z on 20 Apr 2018
IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare on days one, two, and three (21 Apr, 22 Apr, 23 Apr).
IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet to major storm levels for the past 24 hours. Solar wind speed reached a peak of 637 km/s at 20/1932Z. Total IMF reached 23 nT at 20/0517Z. The maximum southward component of Bz reached -19 nT at 20/0812Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2168 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (21 Apr), quiet to unsettled levels on day two (22 Apr) and quiet levels on day three (23 Apr).
III. Event probabilities 21 Apr-23 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 20 Apr 073
Predicted 21 Apr-23 Apr 075/075/075
90 Day Mean 20 Apr 070
V. Geomagnetic A Indices
Observed Afr/Ap 19 Apr 002/002
Estimated Afr/Ap 20 Apr 029/048
Predicted Afr/Ap 21 Apr-23 Apr 019/025-010/010-005/005
VI. Geomagnetic Activity Probabilities 21 Apr-23 Apr
A. Middle Latitudes
Active 35/30/10
Minor Storm 25/10/01
Major-severe storm 10/01/01
B. High Latitudes
Active 10/20/20
Minor Storm 25/30/20
Major-severe storm 55/35/10