Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 September 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 271 Issued at 2200Z on 28 Sep 2019

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 0 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (29 Sep, 30 Sep, 01 Oct).

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at unsettled to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 713 km/s at 27/2328Z. Total IMF reached 7 nT at 27/2142Z. The maximum southward component of Bz reached -5 nT at 28/0433Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 16380 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (29 Sep), quiet to active levels on day two (30 Sep) and quiet to unsettled levels on day three (01 Oct).

III. Event probabilities 29 Sep-01 Oct
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 28 Sep 067
Predicted 29 Sep-01 Oct 067/067/067
90 Day Mean 28 Sep 067

V. Geomagnetic A Indices
Observed Afr/Ap 27 Sep 015/017
Estimated Afr/Ap 28 Sep 023/032
Predicted Afr/Ap 29 Sep-01 Oct 015/020-010/012-007/010

VI. Geomagnetic Activity Probabilities 29 Sep-01 Oct
A. Middle Latitudes
Active 35/30/25
Minor Storm 25/10/10
Major-severe storm 10/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 20/25/25
Major-severe storm 60/40/35