Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 May 2016

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 139 Issued at 2200Z on 18 May 2016

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: 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 (19 May, 20 May, 21 May).

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 566 km/s at 17/2109Z. Total IMF reached 8 nT at 18/1054Z. The maximum southward component of Bz reached -6 nT at 18/1014Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 987 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and three (19 May, 21 May) and unsettled to minor storm levels on day two (20 May).

III. Event probabilities 19 May-21 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 May 102
Predicted 19 May-21 May 103/105/105
90 Day Mean 18 May 093

V. Geomagnetic A Indices
Observed Afr/Ap 17 May 014/012
Estimated Afr/Ap 18 May 008/008
Predicted Afr/Ap 19 May-21 May 014/016-017/022-011/016

VI. Geomagnetic Activity Probabilities 19 May-21 May
A. Middle Latitudes
Active 35/35/35
Minor Storm 25/30/15
Major-severe storm 05/10/05
B. High Latitudes
Active 10/10/10
Minor Storm 25/20/25
Major-severe storm 55/65/50