Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 May 2016

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 142 Issued at 2200Z on 21 May 2016

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: 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 21/1400Z from Region 2546 (S07W21). There are currently 1 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 (22 May, 23 May, 24 May).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 545 km/s at 21/0520Z. Total IMF reached 11 nT at 21/0541Z. The maximum southward component of Bz reached -9 nT at 21/0630Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 612 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (22 May), quiet to unsettled levels on day two (23 May) and quiet levels on day three (24 May).

III. Event probabilities 22 May-24 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 May 098
Predicted 22 May-24 May 095/095/095
90 Day Mean 21 May 093

V. Geomagnetic A Indices
Observed Afr/Ap 20 May 006/006
Estimated Afr/Ap 21 May 013/017
Predicted Afr/Ap 22 May-24 May 016/018-008/008-005/005

VI. Geomagnetic Activity Probabilities 22 May-24 May
A. Middle Latitudes
Active 35/20/10
Minor Storm 20/05/01
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 25/25/20
Major-severe storm 50/30/15