Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 April 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 108 Issued at 2200Z on 17 Apr 2020

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: 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 (18 Apr, 19 Apr, 20 Apr).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 344 km/s at 17/1847Z. Total IMF reached 5 nT at 17/1248Z. The maximum southward component of Bz reached -4 nT at 17/0647Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 194 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expectedto be at quiet levels on days one and two (18 Apr, 19 Apr) and quiet to active levels on day three (20 Apr).

III. Event probabilities 18 Apr-20 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Apr 068
Predicted 18 Apr-20 Apr 069/069/069
90 Day Mean 17 Apr 071

V. Geomagnetic A Indices
Observed Afr/Ap 16 Apr 005/005
Estimated Afr/Ap 17 Apr 005/005
Predicted Afr/Ap 18 Apr-20 Apr 006/005-006/005-009/012

VI. Geomagnetic Activity Probabilities 18 Apr-20 Apr
A. Middle Latitudes
Active 10/10/30
Minor Storm 01/01/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/30
Major-severe storm 10/10/40