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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 211 Issued at 2200Z on 30 Jul 2021

IA. Analysis of Solar Active Regions and Activity from 29/2100Z to 30/2100Z: 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 (31 Jul, 01 Aug, 02 Aug).

IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 522 km/s at 30/1220Z. Total IMF reached 5 nT at 30/0355Z. The maximum southward component of Bz reached -3 nT at 30/0629Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 779 pfu.

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

III. Event probabilities 31 Jul-02 Aug
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 30 Jul 076
Predicted 31 Jul-02 Aug 076/074/072
90 Day Mean 30 Jul 079

V. Geomagnetic A Indices
Observed Afr/Ap 29 Jul 012/009
Estimated Afr/Ap 30 Jul 007/008
Predicted Afr/Ap 31 Jul-02 Aug 008/010-010/012-007/008

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