Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 August 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 237 Issued at 2200Z on 25 Aug 2013

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to
25/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 4 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 (26 Aug,
27 Aug, 28 Aug).

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: 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
456 km/s at 25/0703Z. Total IMF reached 6 nT at 24/2118Z. The maximum
southward component of Bz reached -4 nT at 25/1005Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 1871 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (26 Aug, 27 Aug)
and quiet levels on day three (28 Aug).

III. Event probabilities 26 Aug-28 Aug
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 25 Aug 113
Predicted 26 Aug-28 Aug 110/105/100
90 Day Mean 25 Aug 113

V. Geomagnetic A Indices
Observed Afr/Ap 24 Aug 008/008
Estimated Afr/Ap 25 Aug 009/009
Predicted Afr/Ap 26 Aug-28 Aug 011/012-009/008-006/005

VI. Geomagnetic Activity Probabilities 26 Aug-28 Aug
A. Middle Latitudes
Active 20/15/10
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/25/15
Major-severe storm 30/20/10