Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 049 Issued at 2200Z on 18 Feb 2012
IA. Analysis of Solar Active Regions and Activity from 17/2100Z
to 18/2100Z: Solar activity was at very low levels. New Region 1421
(N17E59) rotated onto the disk as a simple unipolar group. The
remainder of the disk and limb was quiet and stable. No
Earth-directed CMEs were detected.
IB. Solar Activity Forecast: Solar activity is expected to be very
low with a chance for C-class activity for the next three days (19 -
21 February).
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was at quiet levels. ACE solar wind velocities
were steady at 300 km/s through about 18/1500Z while the Bz
component of the interplanetary magnetic field remained mostly
north. After 1500Z, wind speed, temperature and density all
indicated gradual increases, while Bz indicated some rotation
through +/- 7 nT. These signatures were indicative of a co-rotating
interaction region in advance of a coronal hole high speed stream
(CH HSS).
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels, with isolated active
periods, on day one (19 February) due to recurrent CH HSS effects.
By days two and three (20 - 21 February), a return to mostly quiet
levels is expected.
III. Event Probabilities 19 Feb-21 Feb
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 18 Feb 104
Predicted 19 Feb-21 Feb 105/110/110
90 Day Mean 18 Feb 131
V. Geomagnetic A Indices
Observed Afr/Ap 17 Feb 002/002
Estimated Afr/Ap 18 Feb 003/005
Predicted Afr/Ap 19 Feb-21 Feb 008/008-004/005-003/005
VI. Geomagnetic Activity Probabilities 19 Feb-21 Feb
A. Middle Latitudes
Active 30/10/05
Minor storm 10/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 40/20/10
Minor storm 20/05/05
Major-severe storm 05/01/01
