Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 22 September 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 265 Issued at 2200Z on 22 Sep 2017

IA.  Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 2 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 (23 Sep, 24 Sep, 25 Sep).

IIA.  Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 480 km/s at 21/2217Z. Total IMF reached 6 nT at 22/1615Z. The maximum southward component of Bz reached -5 nT at 22/1655Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 36942 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (23 Sep) and quiet to active levels on days two and three (24 Sep, 25 Sep).

III.  Event probabilities 23 Sep-25 Sep
Class M    15/15/15
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           22 Sep 078
Predicted   23 Sep-25 Sep 085/090/090
90 Day Mean        22 Sep 081

V.  Geomagnetic A Indices
Observed Afr/Ap 21 Sep  007/007
Estimated Afr/Ap 22 Sep  005/005
Predicted Afr/Ap 23 Sep-25 Sep  007/008-009/012-014/016

VI.  Geomagnetic Activity Probabilities 23 Sep-25 Sep
A.  Middle Latitudes
Active                15/25/30
Minor Storm           05/10/15
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           25/25/25
Major-severe storm    25/40/50