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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 243 Issued at 2200Z on 31 Aug 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 C2 event observed at
31/1736Z from Region 1836 (N11E19). 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 (01 Sep,
02 Sep, 03 Sep).

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: 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
496 km/s at 31/2050Z. Total IMF reached 9 nT at 30/2107Z. The maximum
southward component of Bz reached -8 nT at 30/2122Z.

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

III. Event probabilities 01 Sep-03 Sep
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 31 Aug 108
Predicted 01 Sep-03 Sep 110/110/112
90 Day Mean 31 Aug 114

V. Geomagnetic A Indices
Observed Afr/Ap 30 Aug 007/007
Estimated Afr/Ap 31 Aug 013/015
Predicted Afr/Ap 01 Sep-03 Sep 018/025-013/015-006/005

VI. Geomagnetic Activity Probabilities 01 Sep-03 Sep
A. Middle Latitudes
Active 45/35/10
Minor Storm 30/15/01
Major-severe storm 05/01/01
B. High Latitudes
Active 05/15/15
Minor Storm 20/30/15
Major-severe storm 70/45/10