Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 August 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 240 Issued at 2200Z on 28 Aug 2013

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 3 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 (29 Aug, 30 Aug, 31 Aug).

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 513 km/s at 28/0506Z. Total IMF reached 11 nT at 27/2100Z. The maximum southward component of Bz reached -7 nT at 28/0038Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (29 Aug) and quiet to minor storm levels on days two and three (30 Aug, 31 Aug).

III. Event probabilities 29 Aug-31 Aug
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 28 Aug 108
Predicted 29 Aug-31 Aug 108/105/100
90 Day Mean 28 Aug 114

V. Geomagnetic A Indices
Observed Afr/Ap 27 Aug 012/019
Estimated Afr/Ap 28 Aug 009/010
Predicted Afr/Ap 29 Aug-31 Aug 007/008-014/020-016/020

VI. Geomagnetic Activity Probabilities 29 Aug-31 Aug
A. Middle Latitudes
Active 15/40/40
Minor Storm 01/25/25
Major-severe storm 01/05/05
B. High Latitudes
Active 15/10/10
Minor Storm 25/25/25
Major-severe storm 20/65/60