Viewing archive of Friday, 21 May 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 May 21 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 142 Issued at 2200Z on 21 May 2004

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

Solar activity was low during the past 24 hours due to two C-class flares: a C2 at 0551 UTC from Region 618 (S11E55) and a C2 at 1623 UTC from Region 617 (S11W46). Region 618 has shown a slow growth trend and Region 617 appears to be decaying. The remainder of the solar disk and limbs were quiet and stable.
IB. Solar Activity Forecast
Solar activity is expected to continue at low levels for the next three days (21-23 May). Region 618 is expected to be the main source for activity.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to unsettled during the past 24 hours The solar wind speed remains somewhat elevated: there was a slow declining trend up until 1800 UTC, after which speeds increased again, with values around 500 km/s by forecast issue time.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be mostly unsettled with a chance for isolated active periods at high latitudes for the next 24 hours (22 May). Unsettled conditions should prevail for the second day (23 May) and conditions should decline to quiet to unsettled by the third day (24 May).
III. Event Probabilities 22 May to 24 May
Class M15%15%15%
Class X01%01%01%
Proton01%01%01%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       21 May 107
  Predicted   22 May-24 May  105/105/100
  90 Day Mean        21 May 105
V. Geomagnetic A Indices
  Observed Afr/Ap 20 May  011/013
  Estimated     Afr/Ap 21 May  012/010
  Predicted    Afr/Ap 22 May-24 May  010/015-010/012-005/008
VI. Geomagnetic Activity Probabilities 22 May to 24 May
A. Middle Latitudes
Active30%25%20%
Minor storm15%15%10%
Major-severe storm05%05%05%
B. High Latitudes
Active30%30%15%
Minor storm20%20%10%
Major-severe storm15%15%05%

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-flare2024/12/08X2.2
Last M-flare2024/12/22M1.1
Last geomagnetic storm2024/12/17Kp5+ (G1)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
November 2024152.5 -13.9
December 2024103.3 -49.2
Last 30 days114 -43.9

This day in history*

Solar flares
12015M6.75
21998M3.34
32013M2.36
42013M1.97
52001M1.69
DstG
12002-67
22000-62G2
31989-60
42014-57
51982-53G1
*since 1994

Social networks