Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 31 May 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 151 Issued at 2200Z on 31 May 2017

IA.  Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 31/1848Z. There are currently 0 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 (01 Jun, 02 Jun, 03 Jun).

IIA.  Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 538 km/s at 31/0054Z. Total IMF reached 8 nT at 31/2058Z. The maximum southward component of Bz reached -3 nT at 31/1608Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 624 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (01 Jun), quiet to unsettled levels on day two (02 Jun) and quiet to active levels on day three (03 Jun).

III.  Event probabilities 01 Jun-03 Jun
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           31 May 074
Predicted   01 Jun-03 Jun 075/076/077
90 Day Mean        31 May 076

V.  Geomagnetic A Indices
Observed Afr/Ap 30 May  006/006
Estimated Afr/Ap 31 May  004/005
Predicted Afr/Ap 01 Jun-03 Jun  005/005-009/010-011/014

VI.  Geomagnetic Activity Probabilities 01 Jun-03 Jun
A.  Middle Latitudes
Active                10/15/25
Minor Storm           05/05/10
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           15/20/20
Major-severe storm    15/15/20