Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 14 September 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 257 Issued at 2200Z on 14 Sep 2021

IA. Analysis of Solar Active Regions and Activity from 13/2100Z to 14/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 14/0649Z from Region 2868 (S22W90). There are currently 1 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare on days one and two (15 Sep, 16 Sep) and expected to be very low on day three (17 Sep).

IIA. Geophysical Activity Summary 13/2100Z to 14/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 496 km/s at 13/2142Z. Total IMF reached 5 nT at 14/1821Z. The maximum southward component of Bz reached -4 nT at 14/1124Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 332 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (15 Sep, 16 Sep) and quiet to active levels on day three (17 Sep).

III. Event probabilities 15 Sep-17 Sep
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 14 Sep 078
Predicted 15 Sep-17 Sep 078/075/075
90 Day Mean 14 Sep 082

V. Geomagnetic A Indices
Observed Afr/Ap 13 Sep 007/009
Estimated Afr/Ap 14 Sep 006/008
Predicted Afr/Ap 15 Sep-17 Sep 006/005-006/005-011/015

VI. Geomagnetic Activity Probabilities 15 Sep-17 Sep
A. Middle Latitudes
Active 15/10/40
Minor Storm 01/01/20
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/10
Minor Storm 25/20/35
Major-severe storm 20/20/50