Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 26 May 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 146 Issued at 2200Z on 26 May 2017

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 with a chance for a C-class flares on days one, two, and three (27 May, 28 May, 29 May).

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 816 km/s at 26/0143Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 13744 pfu.

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

III.  Event probabilities 27 May-29 May
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           26 May 080
Predicted   27 May-29 May 080/075/070
90 Day Mean        26 May 076

V.  Geomagnetic A Indices
Observed Afr/Ap 25 May  004/004
Estimated Afr/Ap 26 May  008/011
Predicted Afr/Ap 27 May-29 May  015/020-008/010-006/005

VI.  Geomagnetic Activity Probabilities 27 May-29 May
A.  Middle Latitudes
Active                20/15/10
Minor Storm           05/05/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/15
Major-severe storm    15/20/10