Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 26 April 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 116 Issued at 2200Z on 26 Apr 2018

IA.  Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: 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 on days one, two, and three (27 Apr, 28 Apr, 29 Apr).

IIA.  Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 396 km/s at 26/1503Z. Total IMF reached 6 nT at 26/0940Z. The maximum southward component of Bz reached -4 nT at 25/2108Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 4623 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (27 Apr) and quiet levels on days two and three (28 Apr, 29 Apr).

III.  Event probabilities 27 Apr-29 Apr
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           26 Apr 069
Predicted   27 Apr-29 Apr 069/069/068
90 Day Mean        26 Apr 070

V.  Geomagnetic A Indices
Observed Afr/Ap 25 Apr  004/006
Estimated Afr/Ap 26 Apr  006/006
Predicted Afr/Ap 27 Apr-29 Apr  010/012-006/005-006/005

VI.  Geomagnetic Activity Probabilities 27 Apr-29 Apr
A.  Middle Latitudes
Active                30/10/10
Minor Storm           10/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/15/15
Major-severe storm    35/15/15