Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 16 May 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 136 Issued at 2200Z on 16 May 2021

IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (17 May, 18 May, 19 May).

IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 431 km/s at 15/2114Z. Total IMF reached 5 nT at 16/2029Z. The maximum southward component of Bz reached -4 nT at 16/1032Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 197 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (17 May), quiet to minor storm levels on day two (18 May) and unsettled to active levels on day three (19 May).

III. Event probabilities 17 May-19 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 16 May 073
Predicted 17 May-19 May 073/077/077
90 Day Mean 16 May 076

V. Geomagnetic A Indices
Observed Afr/Ap 15 May 008/008
Estimated Afr/Ap 16 May 005/005
Predicted Afr/Ap 17 May-19 May 008/012-013/018-015/020

VI. Geomagnetic Activity Probabilities 17 May-19 May
A. Middle Latitudes
Active 35/35/35
Minor Storm 10/20/20
Major-severe storm 01/05/05
B. High Latitudes
Active 15/10/10
Minor Storm 30/25/25
Major-severe storm 45/50/55