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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 90 Issued at 2200Z on 31 Mar 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 31/1737Z from Region 2645 (S10E01). There are currently 3 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 Apr, 02 Apr, 03 Apr).

IIA.  Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at unsettled to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 771 km/s at 31/1103Z. Total IMF reached 6 nT at 31/0323Z. The maximum southward component of Bz reached -6 nT at 31/0323Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 24539 pfu.

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

III.  Event probabilities 01 Apr-03 Apr
Class M    10/10/10
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           31 Mar 091
Predicted   01 Apr-03 Apr 093/095/095
90 Day Mean        31 Mar 076

V.  Geomagnetic A Indices
Observed Afr/Ap 30 Mar  018/017
Estimated Afr/Ap 31 Mar  021/031
Predicted Afr/Ap 01 Apr-03 Apr  019/025-019/022-014/018

VI.  Geomagnetic Activity Probabilities 01 Apr-03 Apr
A.  Middle Latitudes
Active                40/35/20
Minor Storm           20/20/05
Major-severe storm    05/05/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/15
Major-severe storm    25/30/15