Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 April 2016

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 108 Issued at 2200Z on 17 Apr 2016

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 2 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare 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 to active levels for the past 24 hours. Solar wind speed reached a peak of 478 km/s at 16/2349Z. Total IMF reached 13 nT at 17/1937Z. The maximum southward component of Bz reached -5 nT at 17/0412Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1036 pfu.

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

III. Event probabilities 18 Apr-20 Apr
Class M 15/15/15
Class X 01/01/01
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Apr 102
Predicted 18 Apr-20 Apr 102/102/095
90 Day Mean 17 Apr 099

V. Geomagnetic A Indices
Observed Afr/Ap 16 Apr 008/012
Estimated Afr/Ap 17 Apr 015/018
Predicted Afr/Ap 18 Apr-20 Apr 012/012-010/012-007/008

VI. Geomagnetic Activity Probabilities 18 Apr-20 Apr
A. Middle Latitudes
Active 35/35/20
Minor Storm 10/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/30/25
Major-severe storm 45/45/25