Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 31 July 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 212 Issued at 2200Z on 31 Jul 2013

IA. Analysis of Solar Active Regions and Activity from 30/2100Z to
31/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3 event observed at
30/2219Z from Region 1809 (N12E65). There are currently 7 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low with a
slight chance for an M-class flare on days one, two, and three (01 Aug,
02 Aug, 03 Aug).

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed,
as measured by the ACE spacecraft, reached a peak speed of 437 km/s at
31/0433Z. Total IMF reached 5 nT at 31/0340Z. The maximum southward
component of Bz reached -5 nT at 31/1631Z. Electrons greater than 2 MeV
at geosynchronous orbit reached a peak level of 852 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on day one (01 Aug), quiet to unsettled levels on
day two (02 Aug) and quiet to active levels on day three (03 Aug).

III. Event probabilities 01 Aug-03 Aug
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 31 Jul 109
Predicted 01 Aug-03 Aug 105/105/105
90 Day Mean 31 Jul 118

V. Geomagnetic A Indices
Observed Afr/Ap 30 Jul 006/006
Estimated Afr/Ap 31 Jul 005/005
Predicted Afr/Ap 01 Aug-03 Aug 006/005-006/008-011/012

VI. Geomagnetic Activity Probabilities 01 Aug-03 Aug
A. Middle Latitudes
Active 10/15/30
Minor Storm 01/05/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/25/30
Major-severe storm 10/25/40