Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 5 September 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 248 Issued at 2200Z on 05 Sep 2017

IA.  Analysis of Solar Active Regions and Activity from 04/2100Z to 05/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M4 event observed at 05/0108Z. There are currently 6 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be moderate with a chance for X-class flares on days one, two, and three (06 Sep, 07 Sep, 08 Sep).

IIA.  Geophysical Activity Summary 04/2100Z to 05/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 629 km/s at 05/0140Z. Total IMF reached 8 nT at 04/2145Z. The maximum southward component of Bz reached -6 nT at 04/2207Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 210 pfu at 05/1930Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 3776 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to severe storm levels on day one (06 Sep), active to severe storm levels on day two (07 Sep) and unsettled to active levels on day three (08 Sep). Protons are expected to cross threshold on day one (06 Sep), are likely to cross threshold on day two (07 Sep) and have a slight chance of crossing threshold on day three (08 Sep).

III.  Event probabilities 06 Sep-08 Sep
Class M    75/75/75
Class X    25/25/25
Proton     99/70/15
PCAF       red

IV.  Penticton 10.7 cm Flux
Observed           05 Sep 121
Predicted   06 Sep-08 Sep 120/115/115
90 Day Mean        05 Sep 079

V.  Geomagnetic A Indices
Observed Afr/Ap 04 Sep  016/017
Estimated Afr/Ap 05 Sep  010/012
Predicted Afr/Ap 06 Sep-08 Sep  022/040-026/048-020/022

VI.  Geomagnetic Activity Probabilities 06 Sep-08 Sep
A.  Middle Latitudes
Active                15/15/35
Minor Storm           40/35/15
Major-severe storm    45/50/01
B.  High Latitudes
Active                01/15/15
Minor Storm           10/35/20
Major-severe storm    90/45/20