Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 19 September 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 262 Issued at 2200Z on 19 Sep 2017

IA.  Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low on days one and two (20 Sep, 21 Sep) and expected to be very low with a slight chance for a C-class flare on day three (22 Sep).

IIA.  Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 579 km/s at 18/2302Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 34879 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (20 Sep), quiet to unsettled levels on day two (21 Sep) and quiet levels on day three (22 Sep).

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

IV.  Penticton 10.7 cm Flux
Observed           19 Sep 071
Predicted   20 Sep-22 Sep 072/073/072
90 Day Mean        19 Sep 081

V.  Geomagnetic A Indices
Observed Afr/Ap 18 Sep  021/024
Estimated Afr/Ap 19 Sep  008/009
Predicted Afr/Ap 20 Sep-22 Sep  011/012-008/008-006/005

VI.  Geomagnetic Activity Probabilities 20 Sep-22 Sep
A.  Middle Latitudes
Active                25/20/10
Minor Storm           10/05/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/30/20
Major-severe storm    40/30/20