Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 12 May 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 132 Issued at 2200Z on 12 May 2021

IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: 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 12/0935Z from Region 2822 (N18E05). There are currently 2 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 (13 May, 14 May, 15 May).

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field has been at quiet to severe storm levels for the past 24 hours. Solar wind speed reached a peak of 530 km/s at 12/2034Z. Total IMF reached 23 nT at 12/0837Z. The maximum southward component of Bz reached -19 nT at 12/1212Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 771 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expectedto be at unsettled to minor storm levels on day one (13 May), quiet to unsettled levels on day two (14 May) and quiet levels on day three (15 May).

III. Event probabilities 13 May-15 May
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 12 May 075
Predicted 13 May-15 May 076/078/080
90 Day Mean 12 May 076

V. Geomagnetic A Indices
Observed Afr/Ap 11 May 004/004
Estimated Afr/Ap 12 May 025/053
Predicted Afr/Ap 13 May-15 May 015/022-009/010-006/005

VI. Geomagnetic Activity Probabilities 13 May-15 May
A. Middle Latitudes
Active 40/20/15
Minor Storm 20/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 25/25/20
Major-severe storm 55/25/20