Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 September 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 264 Issued at 2200Z on 21 Sep 2019

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: 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 (22 Sep, 23 Sep, 24 Sep).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 373 km/s at 21/0645Z. Total IMF reached 7 nT at 21/0604Z. The maximum southward component of Bz reached -6 nT at 21/0717Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 954 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (22 Sep), quiet to active levels on day two (23 Sep) and quiet to unsettled levels on day three (24 Sep).

III. Event probabilities 22 Sep-24 Sep
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 Sep 068
Predicted 22 Sep-24 Sep 068/068/068
90 Day Mean 21 Sep 068

V. Geomagnetic A Indices
Observed Afr/Ap 20 Sep 003/004
Estimated Afr/Ap 21 Sep 007/008
Predicted Afr/Ap 22 Sep-24 Sep 005/005-010/012-009/010

VI. Geomagnetic Activity Probabilities 22 Sep-24 Sep
A. Middle Latitudes
Active 05/25/20
Minor Storm 01/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 15/30/25
Major-severe storm 10/30/25