Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 April 2016

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 111 Issued at 2200Z on 20 Apr 2016

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 19/2302Z from Region 2529 (N10W81). There are currently 2 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 levels for the past 24 hours. Solar wind speed reached a peak of 391 km/s at 20/1928Z. Total IMF reached 9 nT at 20/1045Z. The maximum southward component of Bz reached -7 nT at 20/0639Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 310 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (21 Apr, 22 Apr) and quiet to active 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 083
Predicted 21 Apr-23 Apr 085/085/085
90 Day Mean 20 Apr 098

V. Geomagnetic A Indices
Observed Afr/Ap 19 Apr 003/003
Estimated Afr/Ap 20 Apr 004/005
Predicted Afr/Ap 21 Apr-23 Apr 006/005-006/005-010/012

VI. Geomagnetic Activity Probabilities 21 Apr-23 Apr
A. Middle Latitudes
Active 15/15/35
Minor Storm 05/05/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/30
Major-severe storm 20/20/45