Viewing archive of Tuesday, 21 September 2004

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 2004 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 265 Issued at 2200Z on 21 Sep 2004

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

Solar activity was low. Region 672 (N04W86) produced a C7.5 flare at 0836Z. Region 672 will rotate around the west limb on 22 September. Region 673 (S13W04), the only other sunspot group on the visible disk, is in a slow decay phase. No new regions were numbered.
IB. Solar Activity Forecast
Solar activity is expected to be very low with a slight chance for C-class flares from Region 673 and 672 as it rotates around the west limb.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to unsettled with an isolated active period between 0300Z to 0600Z. The active conditions followed a period of southward IMF Bz. Solar wind plasma and magnetic field measurements indicate the presence of a weak coronal hole stream.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet to active with a possibility of reaching minor storm levels on 22 September. Active to minor storm periods are possible on the 22nd due to a weak high speed solar wind stream and the expected impact of a CME that occurred late on 19 September. Levels are expected to return to quiet to unsettled with isolated active periods on 23-24 September.
III. Event Probabilities 22 Sep to 24 Sep
Class M05%05%05%
Class X01%01%01%
Proton05%05%01%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       21 Sep 095
  Predicted   22 Sep-24 Sep  090/090/090
  90 Day Mean        21 Sep 112
V. Geomagnetic A Indices
  Observed Afr/Ap 20 Sep  008/013
  Estimated     Afr/Ap 21 Sep  008/010
  Predicted    Afr/Ap 22 Sep-24 Sep  020/025-010/015-008/010
VI. Geomagnetic Activity Probabilities 22 Sep to 24 Sep
A. Middle Latitudes
Active35%30%20%
Minor storm15%10%05%
Major-severe storm05%05%01%
B. High Latitudes
Active45%35%30%
Minor storm25%20%10%
Major-severe storm10%10%01%

All times in UTC

<< Go to daily overview page

Latest news

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!

100%
Support SpaceWeatherLive with our merchandise
Check out our merchandise

Latest alerts

Get instant alerts!

Space weather facts

Last X-flare2024/11/06X2.39
Last M-flare2024/11/13M1.7
Last geomagnetic storm2024/11/10Kp5+ (G1)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
October 2024166.4 +25
November 2024166 -0.4
Last 30 days163.2 +18.4

This day in history*

Solar flares
11999X1.15
21999M8.06
32005M5.58
41999M4.11
52005M3.72
DstG
11960-167G3
21998-109G2
32012-108G2
41989-105
51979-90G1
*since 1994

Social networks