Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 April 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 107 Issued at 2200Z on 17 Apr 2019

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 very lowwith a slight chance for a C-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 levels for the past 24 hours. Solar wind speed reached a peak of 369 km/s at 16/2100Z. 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 (18 Apr, 19 Apr, 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 076
Predicted   18 Apr-20 Apr 076/074/072
90 Day Mean        17 Apr 072

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Apr  006/008
Estimated Afr/Ap 17 Apr  003/004
Predicted Afr/Ap 18 Apr-20 Apr  006/005-005/005-005/005

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