Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 31 May 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 151 Issued at 2200Z on 31 May 2013

IA. Analysis of Solar Active Regions and Activity from 30/2100Z to
31/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was an M1 event observed at
31/2000Z from Region 1760 (N12E38). There are currently 5 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low
with a chance for a C-class flares and a slight chance for an M-class
flare on days one, two, and three (01 Jun, 02 Jun, 03 Jun).

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: 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
423 km/s at 31/1943Z. Total IMF reached 9 nT at 31/1852Z. The maximum
southward component of Bz reached -8 nT at 31/1710Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 32295 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to minor storm levels on day one (01 Jun), quiet to
active levels on day two (02 Jun) and quiet to unsettled levels on day
three (03 Jun).

III. Event probabilities 01 Jun-03 Jun
Class M 15/15/15
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 31 May 102
Predicted 01 Jun-03 Jun 100/100/110
90 Day Mean 31 May 123

V. Geomagnetic A Indices
Observed Afr/Ap 30 May 002/003
Estimated Afr/Ap 31 May 005/006
Predicted Afr/Ap 01 Jun-03 Jun 011/018-012/015-010/010

VI. Geomagnetic Activity Probabilities 01 Jun-03 Jun
A. Middle Latitudes
Active 25/30/20
Minor Storm 10/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/30/25
Major-severe storm 40/40/30