Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 27 May 2013

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