Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 138 Issued at 2200Z on 18 May 2015
IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: 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 18/0821Z from Region 2349 (S20E34). There are currently 7 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, as measured by the ACE spacecraft, reached a peak speed of 486 km/s at 18/1918Z. Total IMF reached 15 nT at 18/2059Z. The maximum southward component of Bz reached -12 nT at 18/1927Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 4939 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (19 May) and quiet levels on days two and three (20 May, 21 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 115
Predicted 19 May-21 May 110/108/105
90 Day Mean 18 May 128
V. Geomagnetic A Indices
Observed Afr/Ap 17 May 006/006
Estimated Afr/Ap 18 May 009/008
Predicted Afr/Ap 19 May-21 May 010/008-006/005-006/005
VI. Geomagnetic Activity Probabilities 19 May-21 May
