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!

SpaceWeatherLive Pro
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-flare2024/11/24M1.0
Last geomagnetic storm2024/11/10Kp5+ (G1)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
October 2024166.4 +25
November 2024144.7 -21.7
Last 30 days158.6 +10.8

This day in history*

Solar flares
12000X3.4
22000X2.87
32000X2.71
41998X1.54
51999M4.33
DstG
12001-221G4
21982-197G3
31986-86G2
41981-66
51991-65
*since 1994

Social networks