Viewing archive of Tuesday, 18 October 2011

Solar activity report

Report of Solar-Geophysical Activity 2011 Oct 18 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 291 Issued at 2200Z on 18 Oct 2011

IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z

Solar activity was low. A single low-level C-class x-ray flare occurred. No significant changes were observed in Region 1319 (N11W39), which remained an Eki/beta-gamma. Region 1321 (S14E09), a Cao/beta, showed gradual spot growth during the period. Region 1324 (N10E63) rotated more fully into view as a 12-spot Eai/beta group. No new regions were numbered. There were no Earth-directed CMEs observed during the period.
IB. Solar Activity Forecast
Solar activity is expected to be low during the period (19 - 21 October) with a chance for an isolated M-class flare from Regions 1319 or 1324.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
The geomagnetic field was quiet.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet through the period.
III. Event Probabilities 19 Oct to 21 Oct
Class M30%30%30%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       18 Oct 147
  Predicted   19 Oct-21 Oct  145/145/145
  90 Day Mean        18 Oct 119
V. Geomagnetic A Indices
  Observed Afr/Ap 17 Oct  002/004
  Estimated     Afr/Ap 18 Oct  003/005
  Predicted    Afr/Ap 19 Oct-21 Oct  005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 19 Oct to 21 Oct
A. Middle Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%

<< Go to daily overview page

Latest news


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!


Space weather facts

Last X-flare:2017/09/10X8.2
Last M-flare:2017/10/20M1.0
Last geomagnetic storm:2019/10/26Kp5 (G1)
Number of spotless days in 2019:268
Current stretch spotless days:41

This day in history*

Solar flares
*since 1994

Social networks