Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 April 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 112 Issued at 2200Z on 21 Apr 2020

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 0 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (22 Apr, 23 Apr, 24 Apr).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 458 km/s at 21/2053Z. Total IMF reached 15 nT at 21/0240Z. The maximum southward component of Bz reached -9 nT at 21/1542Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 190 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (22 Apr, 23 Apr) and quiet levels on day three (24 Apr).

III. Event probabilities 22 Apr-24 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 Apr 069
Predicted 22 Apr-24 Apr 069/069/069
90 Day Mean 21 Apr 071

V. Geomagnetic A Indices
Observed Afr/Ap 20 Apr 016/023
Estimated Afr/Ap 21 Apr 009/010
Predicted Afr/Ap 22 Apr-24 Apr 007/008-007/010-006/005

VI. Geomagnetic Activity Probabilities 22 Apr-24 Apr
A. Middle Latitudes
Active 15/20/10
Minor Storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/25/20
Major-severe storm 25/30/10