Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 May 2016

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 138 Issued at 2200Z on 17 May 2016

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: 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 17/0408Z from just beyond the western limb. There are currently 2 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low on days one and two (18 May, 19 May) and expected to be very low with a chance for a C-class flares on day three (20 May).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 585 km/s at 17/0642Z. Total IMF reached 7 nT at 17/0303Z. The maximum southward component of Bz reached -6 nT at 17/0840Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1372 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (18 May), quiet to active levels on day two (19 May) and unsettled to minor storm levels on day three (20 May).

III. Event probabilities 18 May-20 May
Class M 05/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 May 103
Predicted 18 May-20 May 105/105/108
90 Day Mean 17 May 093

V. Geomagnetic A Indices
Observed Afr/Ap 16 May 015/014
Estimated Afr/Ap 17 May 011/012
Predicted Afr/Ap 18 May-20 May 008/008-014/016-017/022

VI. Geomagnetic Activity Probabilities 18 May-20 May
A. Middle Latitudes
Active 25/35/35
Minor Storm 05/20/30
Major-severe storm 01/05/10
B. High Latitudes
Active 15/10/10
Minor Storm 30/25/20
Major-severe storm 35/50/60