Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 11 September 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 254 Issued at 2200Z on 11 Sep 2017

IA.  Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity has been at low levels for the past 24 hours. There are currently 2 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on day one (12 Sep) and expected to be very low with a slight chance for a C-class flare on day two (13 Sep) and expected to be very low on day three (14 Sep).

IIA.  Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 668 km/s at 11/0203Z. Total IMF reached 7 nT at 10/2328Z. The maximum southward component of Bz reached -5 nT at 10/2330Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 1493 pfu at 11/1145Z. Protons greater than 100 MeV at geosynchronous orbit reached a peak level of 68 pfu at 10/2215Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 5361 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (12 Sep), unsettled to major storm levels on day two (13 Sep) and unsettled to minor storm levels on day three (14 Sep). Protons are expected to cross threshold on day one (12 Sep), are expected to cross threshold on day two (13 Sep) and are likely to cross threshold on day three (14 Sep).

III.  Event probabilities 12 Sep-14 Sep
Class M    10/01/01
Class X    01/01/01
Proton     99/80/60
PCAF       red

IV.  Penticton 10.7 cm Flux
Observed           11 Sep 080
Predicted   12 Sep-14 Sep 078/076/076
90 Day Mean        11 Sep 081

V.  Geomagnetic A Indices
Observed Afr/Ap 10 Sep  012/007
Estimated Afr/Ap 11 Sep  012/014
Predicted Afr/Ap 12 Sep-14 Sep  010/012-024/040-025/034

VI.  Geomagnetic Activity Probabilities 12 Sep-14 Sep
A.  Middle Latitudes
Active                25/25/30
Minor Storm           10/35/35
Major-severe storm    01/20/20
B.  High Latitudes
Active                15/05/05
Minor Storm           30/20/15
Major-severe storm    40/75/75