Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 042 Issued at 2200Z on 11 Feb 2012
IA. Analysis of Solar Active Regions and Activity from 10/2100Z
to 11/2100Z: Solar activity was low due to a trio of C7 x-ray
events. Regions 1416 (S19W02) and 1417 (N16E44) each produced C7
events at 10/2352Z and 11/1854Z respectively. The third C7 event was
observed at 11/1004Z from behind the east limb near N25. The
activity behind the NE limb portends the return of old Region 1402
(N26, L=218). Region 1416 continued its growth phase, both in area
and spot count, and maintained a beta-gamma magnetic configuration.
At about 10/1900Z, a 27 degree long segmented filament erupted in
the NE quadrant of the disk. The ENE to WSW oriented filament was
centered at N29E14. An associated CME was observed lifting of the NE
limb, first visible in SOHO LASCO C2 imagery at 10/2012Z.
IB. Solar Activity Forecast: Solar activity is expected to be low
with a chance for M-class activity for the next three days (12 - 14
February).
IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z:
The geomagnetic field was at quiet to unsettled levels. ACE solar
wind speeds decreased steadily through the period from 450 km/s to
about 350 km/s. The Bz component of the interplanetary magnetic
field did not vary much beyond +/- 3 nT.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels on days one and two (12
- 13 February) due to coronal hole high speed stream effects. Late
on day two and through day three (14 February), field activity is
expected to increase to unsettled to active levels, with high
latitude minor storm intervals. This increase in activity is due to
anticipated effects from the 10 February CME.
III. Event Probabilities 12 Feb-14 Feb
Class M 30/50/50
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 11 Feb 112
Predicted 12 Feb-14 Feb 120/120/125
90 Day Mean 11 Feb 135
V. Geomagnetic A Indices
Observed Afr/Ap 10 Feb 004/004
Estimated Afr/Ap 11 Feb 004/005
Predicted Afr/Ap 12 Feb-14 Feb 006/008-011/012-014/018
VI. Geomagnetic Activity Probabilities 12 Feb-14 Feb
A. Middle Latitudes
Active 25/35/40
Minor storm 05/15/20
Major-severe storm 01/01/05
B. High Latitudes
Active 30/40/50
Minor storm 15/20/30
Major-severe storm 01/05/10
