Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 April 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 107 Issued at 2200Z on 17 Apr 2018

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 0 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low 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 487 km/s at 17/0757Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 4585 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and three (18 Apr, 20 Apr) and quiet to active levels on day two (19 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 069
Predicted   18 Apr-20 Apr 070/070/070
90 Day Mean        17 Apr 070

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Apr  003/002
Estimated Afr/Ap 17 Apr  004/005
Predicted Afr/Ap 18 Apr-20 Apr  007/008-008/012-007/010

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