Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 22 August 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 234 Issued at 2200Z on 22 Aug 2013

IA. Analysis of Solar Active Regions and Activity from 21/2100Z to
22/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C4 event observed at
22/0506Z from Region 1820 (S12W61). There are currently 9 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with
a slight chance for an M-class flare on days one, two, and three (23
Aug, 24 Aug, 25 Aug).

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: 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
610 km/s at 22/0712Z. Total IMF reached 9 nT at 22/0329Z. The maximum
southward component of Bz reached -6 nT at 22/0411Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 752 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (23 Aug), unsettled to minor
storm levels on day two (24 Aug) and quiet to minor storm levels on day
three (25 Aug).

III. Event probabilities 23 Aug-25 Aug
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 22 Aug 132
Predicted 23 Aug-25 Aug 130/125/120
90 Day Mean 22 Aug 113

V. Geomagnetic A Indices
Observed Afr/Ap 21 Aug 013/020
Estimated Afr/Ap 22 Aug 010/012
Predicted Afr/Ap 23 Aug-25 Aug 012/015-020/025-019/020

VI. Geomagnetic Activity Probabilities 23 Aug-25 Aug
A. Middle Latitudes
Active 30/40/40
Minor Storm 10/25/30
Major-severe storm 01/05/10
B. High Latitudes
Active 15/10/05
Minor Storm 30/25/20
Major-severe storm 45/60/75