Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 20 Issued at 2200Z on 20 Jan 2013
IA. Analysis of Solar Active Regions and Activity from 19/2100Z to
20/2100Z: 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
20/1432Z from Region 1654 (N08W84). There are currently 3 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is likely to be low on day
one (21 Jan). Solar activity is expected to be very low with a chance
for C-class flares on days two and three (22 - 23 Jan).
IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: 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
450 km/s at 19/2230Z. Total IMF reached 8.7 nT at 20/0624Z. The maximum
southward component of Bz reached -8.2 nT at 20/0546Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 250 pfu.
IIB. The geomagnetic field is expected to remain at quiet levels for
days one and two (21 - 22 Jan). The geomagnetic field is expected to
increase to quiet to unsettled levels on day three (23 Jan) in response
to a negative polarity CH/HSS.
III. Event probabilities 21 Jan-23 Jan
Class M 05/01/01
Class X 01/01/01
IV. Penticton 10.7 cm Flux
Observed 20 Jan 107
Predicted 21 Jan-23 Jan 105/105/100
90 Day Mean 20 Jan 121
V. Geomagnetic A Indices
Observed Afr/Ap 19 Jan 009/006
Estimated Afr/Ap 20 Jan 008/010
Predicted Afr/Ap 21 Jan-23 Jan 005/005-006/005-006/008
VI. Geomagnetic Activity Probabilities 21 Jan-23 Jan
A. Middle Latitudes
Minor Storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Minor Storm 15/15/25
Major-severe storm 15/15/20