Viewing archive of Monday, 21 September 1998

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 1998 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 1998

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

SOLAR ACTIVITY WAS LOW. THE LARGEST AND MOST ACTIVE REGION CURRENTLY VISIBLE, REGION 8340 (N19E25), PRODUCED A C2/SF AT 21/0806UT AND A C2/1F AT 21/1842UT. THIS REGION IS STILL UNDERGOING SLOW GROWTH AND IS CURRENTLY A DKO GROUP COVERING 540 MILLIONTHS OF WHITE LIGHT AREA. REMAINING REGIONS WERE QUIET.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO REMAIN LOW. CONTINUED C-CLASS ACTIVITY IS EXPECTED FROM REGION 8340 WITH A SLIGHT CHANCE FOR AN M-CLASS.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED WITH ISOLATED ACTIVE PERIODS IN HIGH LATITUDES.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO REMAIN QUIET TO UNSETTLED WITH OCCASIONAL ACTIVE PERIODS AT HIGH LATITUDES.
III. Event Probabilities 22 SEP to 24 SEP
Class M25%25%25%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       21 SEP 138
  Predicted   22 SEP-24 SEP  140/145/150
  90 Day Mean        21 SEP 128
V. Geomagnetic A Indices
OBSERVED AFR/AP 20 SEP  004/008
ESTIMATED AFR/AP 21 SEP  012/015
PREDICTED AFR/AP 22 SEP-24 SEP  015/015-015/015-015/020
VI. Geomagnetic Activity Probabilities 22 SEP to 24 SEP
A. Middle Latitudes
Active30%30%20%
Minor storm10%10%05%
Major-severe storm01%01%01%
B. High Latitudes
Active40%40%30%
Minor storm15%15%10%
Major-severe storm01%01%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-flare2024/12/08X2.2
Last M-flare2024/12/24M1.0
Last geomagnetic storm2024/12/17Kp5+ (G1)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
November 2024152.5 -13.9
December 2024110.7 -41.8
Last 30 days116.5 -41.7

This day in history*

Solar flares
12011M5.77
21998M1.83
32001M1.76
42001M1.41
52011M1.22
DstG
11988-85
21998-57
31978-57G2
42014-49
52002-39
*since 1994

Social networks