Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 March 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 80 Issued at 2200Z on 21 Mar 2013

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to
21/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3 event observed at
21/1822Z from Region 1692 (N09W85). There are currently 4 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 day one (22 Mar) and expected to
be very low with a chance for a C-class flares on days two and three (23
Mar, 24 Mar).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: 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
574 km/s at 21/0122Z. Total IMF reached 9 nT at 20/2108Z. The maximum
southward component of Bz reached -8 nT at 20/2244Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 1851 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (22 Mar, 23 Mar)
and quiet levels on day three (24 Mar).

III. Event probabilities 22 Mar-24 Mar
Class M 10/05/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 Mar 106
Predicted 22 Mar-24 Mar 105/100/100
90 Day Mean 21 Mar 116

V. Geomagnetic A Indices
Observed Afr/Ap 20 Mar 007/009
Estimated Afr/Ap 21 Mar 011/015
Predicted Afr/Ap 22 Mar-24 Mar 007/008-008/008-006/005

VI. Geomagnetic Activity Probabilities 22 Mar-24 Mar
A. Middle Latitudes
Active 15/15/05
Minor Storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/10
Major-severe storm 20/20/05