Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 12 September 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 255 Issued at 2200Z on 12 Sep 2017

IA.  Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: 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 with a chance for a C-class flares on days one, two, and three (13 Sep, 14 Sep, 15 Sep).

IIA.  Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 652 km/s at 12/2050Z. Total IMF reached 16 nT at 12/2054Z. The maximum southward component of Bz reached -10 nT at 12/1954Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 872 pfu at 11/2105Z. Protons greater than 100 MeV at geosynchronous orbit reached a peak level of 10 pfu at 11/2115Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 7042 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at active to major storm levels on day one (13 Sep), unsettled to minor storm levels on day two (14 Sep) and active to minor storm levels on day three (15 Sep). Protons are expected to cross threshold on day one (13 Sep), are expected to cross threshold on day two (14 Sep) and are likely to cross threshold on day three (15 Sep).

III.  Event probabilities 13 Sep-15 Sep
Class M    01/01/01
Class X    01/01/01
Proton     95/80/60
PCAF       red

IV.  Penticton 10.7 cm Flux
Observed           12 Sep 076
Predicted   13 Sep-15 Sep 075/075/075
90 Day Mean        12 Sep 081

V.  Geomagnetic A Indices
Observed Afr/Ap 11 Sep  008/010
Estimated Afr/Ap 12 Sep  010/013
Predicted Afr/Ap 13 Sep-15 Sep  024/036-025/032-021/030

VI.  Geomagnetic Activity Probabilities 13 Sep-15 Sep
A.  Middle Latitudes
Active                25/30/30
Minor Storm           35/30/25
Major-severe storm    20/15/15
B.  High Latitudes
Active                05/05/05
Minor Storm           20/20/20
Major-severe storm    75/65/65