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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 212 Issued at 2200Z on 31 Jul 2017

IA.  Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 0 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (01 Aug, 02 Aug, 03 Aug).

IIA.  Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speeds averaged around 330 km/s. Total IMF reached 6 nT at 30/2237Z. 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 8563 pfu.

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

III.  Event probabilities 01 Aug-03 Aug
Class M    20/20/20
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           31 Jul 072
Predicted   01 Aug-03 Aug 075/078/080
90 Day Mean        31 Jul 075

V.  Geomagnetic A Indices
Observed Afr/Ap 30 Jul   NA/004
Estimated Afr/Ap 31 Jul  010/012
Predicted Afr/Ap 01 Aug-03 Aug  006/005-009/008-006/005

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