Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 October 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 294 Issued at 2200Z on 21 Oct 2017

IA.  Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 20/2328Z from Region 2685 (S10E85). There are currently 1 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 (22 Oct, 23 Oct, 24 Oct).

IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 485 km/s at 21/2040Z. Total IMF reached 12 nT at 21/1325Z. The maximum southward component of Bz reached -7 nT at 21/1215Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 3951 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (22 Oct), quiet levels on day two (23 Oct) and quiet to minor storm levels on day three (24 Oct).

III.  Event probabilities 22 Oct-24 Oct
Class M    20/20/20
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           21 Oct 077
Predicted   22 Oct-24 Oct 080/082/084
90 Day Mean        21 Oct 082

V.  Geomagnetic A Indices
Observed Afr/Ap 20 Oct  005/008
Estimated Afr/Ap 21 Oct  008/010
Predicted Afr/Ap 22 Oct-24 Oct  009/010-005/005-012/018

VI.  Geomagnetic Activity Probabilities 22 Oct-24 Oct
A.  Middle Latitudes
Active                15/10/30
Minor Storm           05/01/10
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/20/30
Major-severe storm    25/10/45