Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 September 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 260 Issued at 2200Z on 17 Sep 2019

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: 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 (18 Sep, 19 Sep, 20 Sep).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 491 km/s at 17/1318Z. Total IMF reached 7 nT at 17/2024Z. The maximum southward component of Bz reached -5 nT at 17/2039Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1141 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (18 Sep) and quiet levels on days two and three (19 Sep, 20 Sep).

III. Event probabilities 18 Sep-20 Sep
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Sep 068
Predicted 18 Sep-20 Sep 068/068/068
90 Day Mean 17 Sep 068

V. Geomagnetic A Indices
Observed Afr/Ap 16 Sep 010/011
Estimated Afr/Ap 17 Sep 006/008
Predicted Afr/Ap 18 Sep-20 Sep 009/010-005/005-004/005

VI. Geomagnetic Activity Probabilities 18 Sep-20 Sep
A. Middle Latitudes
Active 20/05/05
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/15/15
Major-severe storm 25/10/10