Report of Solar Geophysical Activity (RSGA)

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 147 Issued at 2200Z on 27 May 2013

IA.  Analysis of Solar Active Regions and Activity from 26/2100Z to
27/2100Z: 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
26/2147Z from Region 1756 (S20W26). There are currently 5 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be low with a
slight chance for an M-class flare on days one, two, and three (28 May,
29 May, 30 May).

IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z: 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
805 km/s at 27/1737Z. Total IMF reached 6 nT at 27/1116Z. The maximum
southward component of Bz reached -6 nT at 27/1117Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 58767 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (28 May) and quiet levels
on days two and three (29 May, 30 May).

III.  Event probabilities 28 May-30 May
Class M    15/15/15
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           27 May 110
Predicted   28 May-30 May 110/110/110
90 Day Mean        27 May 123

V.  Geomagnetic A Indices
Observed Afr/Ap 26 May  019/019
Estimated Afr/Ap 27 May  012/014
Predicted Afr/Ap 28 May-30 May  007/008-004/005-005/005

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

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2019
Begin Time: 2013 May 24 1555 UTC
Yesterday Maximum 2MeV Flux: 58800 pfu

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/NOAAscales

Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Radio Events Observed 27 May 2013
A.  245 MHz Bursts
Start  End   Peak Flux  Time of Peak  Duration
0117   0118    660          0118        0001  
0151   0151    250          0151        0000  
0231   0231    120          0231        0000  
B.  245 MHz Noise Storms
No 245 MHz Noise Storms Observed.