Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 1 May 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 121 Issued at 2200Z on 01 May 2013

IA. Analysis of Solar Active Regions and Activity from 30/2100Z to
01/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C9 event observed at
01/0126Z from Region 1730 (S18W48). There are currently 8 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (02 May, 03 May,
04 May).

IIA. Geophysical Activity Summary 30/2100Z to 01/2100Z: The geomagnetic
field has been at unsettled to active levels for the past 24 hours.
Solar wind speed, as measured by the ACE spacecraft, reached a peak
speed of 517 km/s at 01/0913Z. Total IMF reached 11 nT at 01/0703Z. The
maximum southward component of Bz reached -11 nT at 01/0529Z. Electrons
greater than 2 MeV at geosynchronous orbit reached a peak level of 802
pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (02 May), quiet to unsettled
levels on day two (03 May) and quiet levels on day three (04 May).

III. Event probabilities 02 May-04 May
Class M 45/45/45
Class X 05/05/05
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 01 May 159
Predicted 02 May-04 May 165/170/165
90 Day Mean 01 May 114

V. Geomagnetic A Indices
Observed Afr/Ap 30 Apr 006/006
Estimated Afr/Ap 01 May 016/022
Predicted Afr/Ap 02 May-04 May 011/012-008/008-005/005

VI. Geomagnetic Activity Probabilities 02 May-04 May
A. Middle Latitudes
Active 15/10/10
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/15/15
Major-severe storm 25/05/10