Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 30 August 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 242 Issued at 2200Z on 30 Aug 2021

IA. Analysis of Solar Active Regions and Activity from 29/2100Z to 30/2100Z: 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 30/0154Z from Region 2860 (S29W36). There are currently 2 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low with a chance for M-class flares on day one (31 Aug) and likely to be low with a slight chance for an M-class flare on day two (01 Sep) and expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on day three (02 Sep).

IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 438 km/s at 30/0000Z. Total IMF reached 9 nT at 29/2110Z. The maximum southward component of Bz reached -4 nT at 29/2127Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 4481 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (31 Aug), quiet to minor storm levels on day two (01 Sep) and unsettled to major storm levels on day three (02 Sep).

III. Event probabilities 31 Aug-02 Sep
Class M 30/20/10
Class X 05/01/01
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 30 Aug 091
Predicted 31 Aug-02 Sep 090/090/090
90 Day Mean 30 Aug 079

V. Geomagnetic A Indices
Observed Afr/Ap 29 Aug 009/009
Estimated Afr/Ap 30 Aug 011/015
Predicted Afr/Ap 31 Aug-02 Sep 007/008-016/018-023/030

VI. Geomagnetic Activity Probabilities 31 Aug-02 Sep
A. Middle Latitudes
Active 20/40/35
Minor Storm 05/25/30
Major-severe storm 01/05/10
B. High Latitudes
Active 15/10/10
Minor Storm 30/25/25
Major-severe storm 30/65/65