- Press Release
- Dec 6, 2022
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 September 2017
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 261 Issued at 2200Z on 18 Sep 2017
IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: 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 on days one, two, and three (19 Sep, 20 Sep, 21 Sep).
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 707 km/s at 18/1034Z. Total IMF reached 7 nT at 17/2101Z. The maximum southward component of Bz reached -5 nT at 18/0056Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 31067 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (19 Sep, 20 Sep) and quiet to unsettled levels on day three (21 Sep).
III. Event probabilities 19 Sep-21 Sep
Class M 01/01/01
Class X 01/01/01
IV. Penticton 10.7 cm Flux
Observed 18 Sep 072
Predicted 19 Sep-21 Sep 072/072/073
90 Day Mean 18 Sep 081
V. Geomagnetic A Indices
Observed Afr/Ap 17 Sep 013/016
Estimated Afr/Ap 18 Sep 019/024
Predicted Afr/Ap 19 Sep-21 Sep 012/014-011/012-007/008
VI. Geomagnetic Activity Probabilities 19 Sep-21 Sep
A. Middle Latitudes
Minor Storm 15/10/05
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 25/25/25
Major-severe storm 50/40/30