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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 146 Issued at 2200Z on 26 May 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 2 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 and two (27 May, 28 May) and expected to be very low with a slight chance for a C-class flare on day three (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 406 km/s at 25/2224Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 283 pfu.

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

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

IV.  Penticton 10.7 cm Flux
Observed           26 May 073
Predicted   27 May-29 May 073/072/070
90 Day Mean        26 May 069

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

VI.  Geomagnetic Activity Probabilities 27 May-29 May
A.  Middle Latitudes
Active                05/15/15
Minor Storm           01/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           15/25/25
Major-severe storm    05/25/25