Viewing archive of Monday, 21 February 2011
Solar activity report
Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 2011 Feb 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 052 Issued at 2200Z on 21 Feb 2011IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity has been low. Region 1161 (N11W42)
produced multiple C-class events and remains an E-type sunspot group
with a beta-gamma magnetic classification, while Region 1162
(N17W46) remained stable and quiet. The periods largest x-ray event
a C7 at 21/1012Z came from Region 1158 which has rotated off the
visible disk.
IB. Solar Activity Forecast
Solar activity is expected to be low
to moderate with a slight chance for an X-class event from Region
1161 for the next three days (22-24 February).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field has been quiet to unsettled during the past 24
hours. Solar wind data from the ACE spacecraft indicated a slight
drop in velocity to around 380 km/s and sustained negative Bz of
-4nT during the period. The greater than 2 MeV electron flux at
geosynchronous orbit reached high levels during the period.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be quiet to unsettled with a slight chance for isolated
active periods during the next three days (22-24 February).
III. Event Probabilities 22 Feb to 24 Feb
| Class M | 50% | 50% | 50% |
| Class X | 10% | 10% | 10% |
| Proton | 05% | 05% | 05% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Feb 097 Predicted 22 Feb-24 Feb 098/098/095 90 Day Mean 21 Feb 086
V. Geomagnetic A Indices
Observed Afr/Ap 20 Feb 006/007 Estimated Afr/Ap 21 Feb 007/008 Predicted Afr/Ap 22 Feb-24 Feb 007/008-007/008-007/008
VI. Geomagnetic Activity Probabilities 22 Feb to 24 Feb
| 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 | 10% | 10% | 10% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
Latest news
Sunday, 1 February 2026
Complex sunspot region 4366
Monday, 19 January 2026
CME impact! S4 solar radiation storm
Sunday, 18 January 2026
X1.9 solar flare with earth-directed CME
Latest forum messages
AR4366 942Current Farside Activity 362X8 CME 90Space Weather Memes 789Incoming & Unnumbered Active Regions 151
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Solar activity or if there is a chance to see the aurora, but with more traffic comes higher costs to keep the servers online. If you like SpaceWeatherLive and want to support the project you can choose a subscription for an ad-free site or consider a donation. With your help we can keep SpaceWeatherLive online!
Space weather facts
| Last X-flare | 2026/02/04 | X4.3 |
| Last M-flare | 2026/02/05 | M1.1 |
| Last geomagnetic storm | 2026/02/05 | Kp5+ (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| January 2026 | 112.6 -11.4 |
| February 2026 | 140.8 +28.2 |
| Last 30 days | 124.4 +17 |