Report of Solar Geophysical Activity

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 239 Issued at 2200Z on 27 Aug 2015

IA.  Analysis of Solar Active Regions and Activity from 26/2100Z to
27/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M2 event observed at
27/0544Z from Region 2403 (S15W57). There are currently 2 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be moderate
with a slight chance for an X-class flare on days one and two (28 Aug,
29 Aug) and expected to be low with a chance for M-class flares on day
three (30 Aug).

IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic
field has been at active to major storm levels for the past 24 hours.
Solar wind speed, as measured by the ACE spacecraft, reached a peak
speed of 414 km/s at 27/0741Z. Total IMF reached 14 nT at 27/0313Z. The
maximum southward component of Bz reached -13 nT at 27/0319Z. Electrons
greater than 2 MeV at geosynchronous orbit reached a peak level of 915
pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (28 Aug), quiet to
active levels on day two (29 Aug) and quiet to unsettled levels on day
three (30 Aug). Protons greater than 10 MeV have a slight chance of
crossing threshold on days one and two (28 Aug, 29 Aug).

III.  Event probabilities 28 Aug-30 Aug
Class M    60/55/50
Class X    10/10/05
Proton     10/10/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           27 Aug 110
Predicted   28 Aug-30 Aug 110/110/105
90 Day Mean        27 Aug 112

V.  Geomagnetic A Indices
Observed Afr/Ap 26 Aug  019/028
Estimated Afr/Ap 27 Aug  029/045
Predicted Afr/Ap 28 Aug-30 Aug  017/018-011/012-007/008

VI.  Geomagnetic Activity Probabilities 28 Aug-30 Aug
A.  Middle Latitudes
Active                40/30/20
Minor Storm           25/10/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                10/15/15
Minor Storm           25/30/25
Major-severe storm    60/40/25

Radio Events Observed 27 Aug 2015
A.  245 MHz Bursts
Start  End   Peak Flux  Time of Peak  Duration
0249   0249    400          0249        0000  
0301   0301    120          0301        0000  
0349   0349    120          0349        0000  
0358   0358    130          0358        0000  
1454   1454    110          1454        0000  
1718   1719    110          1719        0001  
1841   1841    100          1841        0000  
1854   1854    180          1854        0000  
2010   2010    150          2010        0000  
B.  245 MHz Noise Storms
Start  End   Peak Flux  Time of Peak
1641   1730    530          1700