Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 19 April 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 109 Issued at 2200Z on 19 Apr 2018

IA.  Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity has been at very low levels for the past 24 hours. There is currently 1 numbered sunspot region 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 (20 Apr, 21 Apr, 22 Apr).

IIA.  Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 302 km/s at 19/0231Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1782 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (20 Apr, 21 Apr) and quiet to unsettled levels on day three (22 Apr).

III.  Event probabilities 20 Apr-22 Apr
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           19 Apr 071
Predicted   20 Apr-22 Apr 072/072/072
90 Day Mean        19 Apr 070

V.  Geomagnetic A Indices
Observed Afr/Ap 18 Apr  006/006
Estimated Afr/Ap 19 Apr  005/006
Predicted Afr/Ap 20 Apr-22 Apr  011/015-011/012-007/008

VI.  Geomagnetic Activity Probabilities 20 Apr-22 Apr
A.  Middle Latitudes
Active                35/30/25
Minor Storm           20/10/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                15/15/20
Minor Storm           30/30/30
Major-severe storm    45/35/25