NOAA / Space Weather Prediction Center

Solar Flare 3-day Report of Solar and Geophysical Activity
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Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.
Updated 2014 Aug 28 2200 UTC

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 240 Issued at 2200Z on 28 Aug 2014

IA.  Analysis of Solar Active Regions and Activity from 27/2100Z to
28/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C1 event observed at
28/1520Z from Region 2146 (N08W86). There are currently 6 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 and two (29 Aug, 30
Aug) and likely to be low with a slight chance for an M-class flare on
day three (31 Aug).

IIA.  Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic
field has been at unsettled to minor storm levels for the past 24 hours.
Solar wind speed, as measured by the ACE spacecraft, reached a peak
speed of 386 km/s at 28/1026Z. Total IMF reached 13 nT at 27/2100Z. The
maximum southward component of Bz reached -11 nT at 28/0244Z. Electrons
greater than 2 MeV at geosynchronous orbit reached a peak level of 280

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (29 Aug) and quiet to
unsettled levels on days two and three (30 Aug, 31 Aug). Protons greater
than 10 Mev have a slight chance of crossing threshold on days one and
two (29 Aug, 30 Aug).

III.  Event probabilities 29 Aug-31 Aug
Class M    20/20/10
Class X    01/01/01
Proton     10/10/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           28 Aug 119
Predicted   29 Aug-31 Aug 115/115/115
90 Day Mean        28 Aug 128

V.  Geomagnetic A Indices
Observed Afr/Ap 27 Aug  019/021
Estimated Afr/Ap 28 Aug  016/022
Predicted Afr/Ap 29 Aug-31 Aug  010/010-008/008-011/012

VI.  Geomagnetic Activity Probabilities 29 Aug-31 Aug
A.  Middle Latitudes
Active                35/15/20
Minor Storm           10/01/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/15/15
Major-severe storm    20/10/10