Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 11 May 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 131 Issued at 2200Z on 11 May 2021

IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity has been at very low levels for the past 24 hours. 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 (12 May, 13 May, 14 May).

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 359 km/s at 11/0600Z. Total IMF reached 5 nT at 10/2101Z. The maximum southward component of Bz reached -3 nT at 10/2101Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 220 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (12 May, 13 May) and quiet to unsettled levels on day three (14 May).

III. Event probabilities 12 May-14 May
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 11 May 076
Predicted 12 May-14 May 076/078/078
90 Day Mean 11 May 076

V. Geomagnetic A Indices
Observed Afr/Ap 10 May 008/006
Estimated Afr/Ap 11 May 004/005
Predicted Afr/Ap 12 May-14 May 007/008-014/016-007/008

VI. Geomagnetic Activity Probabilities 12 May-14 May
A. Middle Latitudes
Active 30/35/20
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 40/45/25