Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 April 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 108 Issued at 2200Z on 18 Apr 2019

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: 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 very low with a slight chance for a C-class flare on days one, two, and three (19 Apr, 20 Apr, 21 Apr).

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 481 km/s at 18/1728Z. Total IMF reached 5 nT at 18/0933Z. The maximum southward component of Bz reached -2 nT at 18/1738Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 733 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (19 Apr, 20 Apr, 21 Apr).

III. Event probabilities 19 Apr-21 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 Apr 075
Predicted 19 Apr-21 Apr 075/070/070
90 Day Mean 18 Apr 072

V. Geomagnetic A Indices
Observed Afr/Ap 17 Apr 003/004
Estimated Afr/Ap 18 Apr 005/005
Predicted Afr/Ap 19 Apr-21 Apr 005/005-005/005-006/005

VI. Geomagnetic Activity Probabilities 19 Apr-21 Apr
A. Middle Latitudes
Active 10/10/15
Minor Storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/20
Major-severe storm 20/20/15