Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 13 May 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 133 Issued at 2200Z on 13 May 2021

IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: 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 (14 May, 15 May, 16 May).

IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 544 km/s at 12/2302Z. Total IMF reached 17 nT at 12/2112Z. The maximum southward component of Bz reached -6 nT at 13/0027Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 128 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (14 May) and quiet levels on days two and three (15 May, 16 May).

III. Event probabilities 14 May-16 May
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 13 May 075
Predicted 14 May-16 May 075/075/075
90 Day Mean 13 May 076

V. Geomagnetic A Indices
Observed Afr/Ap 12 May 025/037
Estimated Afr/Ap 13 May 007/008
Predicted Afr/Ap 14 May-16 May 008/005-006/005-006/005

VI. Geomagnetic Activity Probabilities 14 May-16 May
A. Middle Latitudes
Active 20/15/15
Minor Storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/20/20
Major-severe storm 25/20/20