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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 31 Issued at 2200Z on 31 Jan 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 3 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 (01 Feb, 02 Feb, 03 Feb).

IIA.  Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at unsettled to active levels for the past 24 hours. Solar wind speed reached a peak of 796 km/s at 31/2041Z. Total IMF reached 17 nT at 31/1154Z. The maximum southward component of Bz reached -12 nT at 31/1442Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 656 pfu.

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

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

IV.  Penticton 10.7 cm Flux
Observed           31 Jan 076
Predicted   01 Feb-03 Feb 076/076/076
90 Day Mean        31 Jan 077

V.  Geomagnetic A Indices
Observed Afr/Ap 30 Jan  005/005
Estimated Afr/Ap 31 Jan  017/025
Predicted Afr/Ap 01 Feb-03 Feb  015/020-015/018-012/015

VI.  Geomagnetic Activity Probabilities 01 Feb-03 Feb
A.  Middle Latitudes
Active                45/30/30
Minor Storm           25/10/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                10/15/15
Minor Storm           25/30/35
Major-severe storm    60/40/45
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