Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 19 July 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 200 Issued at 2200Z on 19 Jul 2021

IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: 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 19/1907Z. There are currently 3 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares on days one, two, and three (20 Jul, 21 Jul, 22 Jul).

IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 450 km/s at 19/1847Z. Total IMF reached 7 nT at 19/1240Z. The maximum southward component of Bz reached -6 nT at 19/1311Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 403 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (20 Jul) and quiet to unsettled levels on days two and three (21 Jul, 22 Jul).

III. Event probabilities 20 Jul-22 Jul
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 19 Jul 083
Predicted 20 Jul-22 Jul 084/088/088
90 Day Mean 19 Jul 078

V. Geomagnetic A Indices
Observed Afr/Ap 18 Jul 005/003
Estimated Afr/Ap 19 Jul 008/008
Predicted Afr/Ap 20 Jul-22 Jul 006/005-007/008-009/008

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