Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 August 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 229 Issued at 2200Z on 17 Aug 2013

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to
17/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M3 event observed at
17/1824Z from Region 1818 (S07W33). There are currently 6 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (18 Aug, 19 Aug,
20 Aug).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: 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
812 km/s at 17/0521Z. Electrons greater than 2 MeV at geosynchronous
orbit reached a peak level of 4301 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on day one (18 Aug), quiet to unsettled levels on
day two (19 Aug) and quiet to active levels on day three (20 Aug).

III. Event probabilities 18 Aug-20 Aug
Class M 25/25/25
Class X 05/05/05
Proton 25/25/25
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Aug 125
Predicted 18 Aug-20 Aug 130/130/120
90 Day Mean 17 Aug 113

V. Geomagnetic A Indices
Observed Afr/Ap 16 Aug 027/028
Estimated Afr/Ap 17 Aug 006/007
Predicted Afr/Ap 18 Aug-20 Aug 007/008-008/008-010/012

VI. Geomagnetic Activity Probabilities 18 Aug-20 Aug
A. Middle Latitudes
Active 15/15/25
Minor Storm 01/01/10
Major-severe storm 01/01/01
B. High Latitudes
Active 20/20/15
Minor Storm 35/35/35
Major-severe storm 25/25/35