Viewing archive of Wednesday, 21 September 2011

Solar activity report

Report of Solar-Geophysical Activity 2011 Sep 21 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 264 Issued at 2200Z on 21 Sep 2011

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

Solar activity was moderate. An M1 flare was observed at 21/1223Z from Region 1301 (N20E41). Regions 1295 (N22W47) and 1301 showed increases in area and produced occasional C-class flares during the period. Three CMEs were observed towards the NE quadrant, none of which are expected to be geoeffective.
IB. Solar Activity Forecast
Solar activity is expected to be low with a chance for isolated M-class flares from Regions 1295 and 1301 during the period (22-24 September).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was at quiet levels at mid-latitudes, with isolated unsettled to active levels at high-latitudes.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at predominantly quiet levels during the period (22-24 September).
III. Event Probabilities 22 Sep to 24 Sep
Class M45%45%45%
Class X10%10%10%
Proton01%01%01%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       21 Sep 144
  Predicted   22 Sep-24 Sep  144/144/140
  90 Day Mean        21 Sep 104
V. Geomagnetic A Indices
  Observed Afr/Ap 20 Sep  006/006
  Estimated     Afr/Ap 21 Sep  004/005
  Predicted    Afr/Ap 22 Sep-24 Sep  005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 22 Sep to 24 Sep
A. Middle Latitudes
Active05%05%05%
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Active10%10%10%
Minor storm01%01%01%
Major-severe storm01%01%01%

<< Go to daily overview page

Support SpaceWeatherLive.com!

A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!

79%

Space weather facts

Last X-flare2017/09/10X8.2
Last M-flare2020/05/29M1.1
Last geomagnetic storm2020/04/20Kp5 (G1)
Spotless days
Last 365 days294 days
2020157 days (72%)
Last spotless day2020/07/20

This day in history*

Solar flares
11999M1.7
22016M1.3
31999M1.2
42002M1.1
52001M1.1
ApG
1200632G2
2200332G3
3199824G2
4200722G1
5201518G1
*since 1994

Social networks