Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 048 Issued at 2200Z on 17 Feb 2012
IA. Analysis of Solar Active Regions and Activity from 16/2100Z
to 17/2100Z: Solar activity was at very low levels. Region 1418
(S23W55) redeveloped spots as a B-type group. The remaining regions
were quiet and stable. Two filament eruptions were observed during
the period. The first eruption was a 9 degree long filament
centered near N26E41 that lifted off at about 17/0130Z. The second
eruption was a 16 degree long filament centered near S33W17 that
lifted off at about 17/0553Z. LASCO C2 imagery observed a very
faint, slow-moving CME off the SSE limb first visible about
17/0745Z. This CME does not appear to have an Earth-directed
component.
IB. Solar Activity Forecast: Solar activity is expected to be very
low with a chance for C-class activity for the next three days (18 -
20 February).
IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was at quiet levels. ACE solar wind velocities
decreased during the period from about 350 km/s to near 300 km/s
while the Bz component of the interplanetary magnetic field did not
vary much beyond +/- 4 nT.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at mostly quiet levels through most of day one (18
February). By late on day one and through day two (19 February),
field activity is expected to increase to quiet to unsettled levels,
with isolated active periods, due to recurrent coronal hole high
speed stream effects. A return to mostly quiet conditions is
expected by day three (20 February).
III. Event Probabilities 18 Feb-20 Feb
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 17 Feb 104
Predicted 18 Feb-20 Feb 105/100/110
90 Day Mean 17 Feb 132
V. Geomagnetic A Indices
Observed Afr/Ap 16 Feb 004/003
Estimated Afr/Ap 17 Feb 002/002
Predicted Afr/Ap 18 Feb-20 Feb 007/008-008/008-004/005
VI. Geomagnetic Activity Probabilities 18 Feb-20 Feb
A. Middle Latitudes
Active 30/30/15
Minor storm 15/15/01
Major-severe storm 01/01/01
B. High Latitudes
Active 40/40/20
Minor storm 20/20/05
Major-severe storm 05/05/01
