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

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

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to
21/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 3 numbered sunspot regions on the disk.
Region 1658 (S12W46) produced the largest flare of the period, a B4
flare, at 21/0930Z. Region 1654 (N09W88) produced two B3 flares while
Region 1660 (N12W15) was fairly quiet, yet was the most magnetically
complex region on the disk. It has continued to show growth in the
trailer spots and extended its length from five degrees to just over
seven. This region currently appears to be a Dai/Beta-Gamma region and
will be the area of interest for the next few days.
IB. Solar Activity Forecast: Solar activity is expected to be at low
levels on days one, two, and three (22 Jan, 23 Jan, 24 Jan).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed,
as measured by the ACE spacecraft, reached a peak speed of 409 km/s at
21/0029Z. Total IMF reached 16.2 nT at 21/1513Z. The maximum southward
component of Bz reached -5.2 nT at 21/1513Z. Electrons greater than 2
MeV at geosynchronous orbit reached a peak level of 268 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels for the next three days (22 Jan, 23 Jan, 24 Jan).

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

IV. Penticton 10.7 cm Flux
Observed 21 Jan 108
Predicted 22 Jan-24 Jan 105/100/095
90 Day Mean 21 Jan 121

V. Geomagnetic A Indices
Observed Afr/Ap 20 Jan 008/008
Estimated Afr/Ap 21 Jan 004/004
Predicted Afr/Ap 22 Jan-24 Jan 006/005-006/005-006/005

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