Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 29 August 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 241 Issued at 2200Z on 29 Aug 2021

IA. Analysis of Solar Active Regions and Activity from 28/2100Z to 29/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C8 event observed at 29/1003Z from Region 2860 (S29W23). There are currently 2 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (30 Aug, 31 Aug, 01 Sep).

IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 431 km/s at 29/2015Z. Total IMF reached 11 nT at 29/2021Z. The maximum southward component of Bz reached -6 nT at 29/2011Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 11665 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on days one and three (30 Aug, 01 Sep) and quiet to unsettled levels on day two (31 Aug).

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

IV. Penticton 10.7 cm Flux
Observed 29 Aug 089
Predicted 30 Aug-01 Sep 090/090/090
90 Day Mean 29 Aug 079

V. Geomagnetic A Indices
Observed Afr/Ap 28 Aug 017/017
Estimated Afr/Ap 29 Aug 010/014
Predicted Afr/Ap 30 Aug-01 Sep 022/025-007/008-013/018

VI. Geomagnetic Activity Probabilities 30 Aug-01 Sep
A. Middle Latitudes
Active 30/20/40
Minor Storm 40/05/25
Major-severe storm 25/01/05
B. High Latitudes
Active 05/15/10
Minor Storm 15/30/25
Major-severe storm 80/30/65