Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 May 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 143 Issued at 2200Z on 23 May 2017

IA.  Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 4 numbered sunspot regions 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 (24 May, 25 May, 26 May).

IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 592 km/s at 23/0307Z. Total IMF reached 5 nT at 22/2103Z. The maximum southward component of Bz reached -5 nT at 22/2108Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 9337 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (24 May), quiet levels on day two (25 May) and quiet to active levels on day three (26 May).

III.  Event probabilities 24 May-26 May
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           23 May 076
Predicted   24 May-26 May 075/075/075
90 Day Mean        23 May 077

V.  Geomagnetic A Indices
Observed Afr/Ap 22 May  009/009
Estimated Afr/Ap 23 May  008/009
Predicted Afr/Ap 24 May-26 May  007/008-005/005-010/012

VI.  Geomagnetic Activity Probabilities 24 May-26 May
A.  Middle Latitudes
Active                05/10/20
Minor Storm           01/01/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           15/15/20
Major-severe storm    05/10/20