- Press Release
- Sep 27, 2022
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 July 2021
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 199 Issued at 2200Z on 18 Jul 2021
IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 3 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, two, and three (19 Jul, 20 Jul, 21 Jul).
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 407 km/s at 18/1050Z. Total IMF reached 5 nT at 17/2259Z. The maximum southward component of Bz reached -3 nT at 18/1324Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 315 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (19 Jul, 20 Jul, 21 Jul).
III. Event probabilities 19 Jul-21 Jul
Class M 01/01/01
Class X 01/01/01
IV. Penticton 10.7 cm Flux
Observed 18 Jul 080
Predicted 19 Jul-21 Jul 080/085/085
90 Day Mean 18 Jul 078
V. Geomagnetic A Indices
Observed Afr/Ap 17 Jul 004/004
Estimated Afr/Ap 18 Jul 004/004
Predicted Afr/Ap 19 Jul-21 Jul 006/005-006/005-007/008
VI. Geomagnetic Activity Probabilities 19 Jul-21 Jul
A. Middle Latitudes
Minor Storm 01/01/05
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 20/20/25
Major-severe storm 10/10/25