Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 February 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 51 Issued at 2200Z on 20 Feb 2021

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 on days one, two, and three (21 Feb, 22 Feb, 23 Feb).

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at unsettled to active levels for the past 24 hours. component of Bz reached -9 nT at 19/2101Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 858 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (21 Feb) and quiet to unsettled levels on days two and three (22 Feb, 23 Feb).

III. Event probabilities 21 Feb-23 Feb
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 20 Feb 076
Predicted 21 Feb-23 Feb 076/076/076
90 Day Mean 20 Feb 082

V. Geomagnetic A Indices
Observed Afr/Ap 19 Feb 013/ NA
Estimated Afr/Ap 20 Feb 017/022
Predicted Afr/Ap 21 Feb-23 Feb 009/018-008/010-008/008

VI. Geomagnetic Activity Probabilities 21 Feb-23 Feb
A. Middle Latitudes
Active 30/20/15
Minor Storm 10/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/20
Minor Storm 30/25/25
Major-severe storm 40/30/20