Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 April 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 113 Issued at 2200Z on 23 Apr 2018

IA.  Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 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 (24 Apr, 25 Apr, 26 Apr).

IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 458 km/s at 22/2109Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 21958 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (24 Apr, 25 Apr) and quiet to unsettled levels on day three (26 Apr).

III.  Event probabilities 24 Apr-26 Apr
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           23 Apr 074
Predicted   24 Apr-26 Apr 074/074/074
90 Day Mean        23 Apr 070

V.  Geomagnetic A Indices
Observed Afr/Ap 22 Apr  005/005
Estimated Afr/Ap 23 Apr  004/005
Predicted Afr/Ap 24 Apr-26 Apr  006/005-006/005-007/008

VI.  Geomagnetic Activity Probabilities 24 Apr-26 Apr
A.  Middle Latitudes
Active                10/10/20
Minor Storm           01/01/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/20
Minor Storm           15/15/25
Major-severe storm    10/10/20