Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 9 April 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 99 Issued at 2200Z on 09 Apr 2021

IA. Analysis of Solar Active Regions and Activity from 08/2100Z to 09/2100Z: 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 (10 Apr, 11 Apr, 12 Apr).

IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 431 km/s at 08/2112Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 165 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (10 Apr, 11 Apr) and quiet levels on day three (12 Apr).

III. Event probabilities 10 Apr-12 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 09 Apr 078
Predicted 10 Apr-12 Apr 072/072/072
90 Day Mean 09 Apr 076

V. Geomagnetic A Indices
Observed Afr/Ap 08 Apr 003/004
Estimated Afr/Ap 09 Apr 004/005
Predicted Afr/Ap 10 Apr-12 Apr 008/010-008/008-006/005

VI. Geomagnetic Activity Probabilities 10 Apr-12 Apr
A. Middle Latitudes
Active 25/25/10
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 20/20/15
Minor Storm 30/30/20
Major-severe storm 30/25/20