Viewing archive of Friday, 21 September 2001

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 2001 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 2001

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

Solar activity was low. The largest flare of the past day was a C7/Sf at 21/0702 UTC in Region 9631 (N09W24). Regions 9620 (N11E04), 9628 (S18E38), and 9632 (S17E56) also produced C-class subflares. The largest, most magnetically complex sunspot groups appear to be 9628 and 9632.
IB. Solar Activity Forecast
Solar activity is expected to be low to moderate. M-class activity is possible from a number of areas, including Regions 9620, 9628, and 9632.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to unsettled.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet to unsettled.
III. Event Probabilities 22 Sep to 24 Sep
Class M80%80%80%
Class X10%10%10%
Proton05%05%05%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       21 Sep 239
  Predicted   22 Sep-24 Sep  245/250/250
  90 Day Mean        21 Sep 165
V. Geomagnetic A Indices
  Observed Afr/Ap 20 Sep  007/005
  Estimated     Afr/Ap 21 Sep  006/009
  Predicted    Afr/Ap 22 Sep-24 Sep  010/015-010/012-010/010
VI. Geomagnetic Activity Probabilities 22 Sep to 24 Sep
A. Middle Latitudes
Active20%20%20%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active30%30%30%
Minor storm10%10%10%
Major-severe storm01%01%01%

<< 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!

23%
Support SpaceWeatherLive with our merchandise
Check out our merchandise

Latest alerts

Get instant alerts!

Space weather facts

Last X-flare2024/03/23X1.1
Last M-flare2024/03/28M7.0
Last geomagnetic storm2024/03/25Kp5 (G1)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
February 2024124.7 +1.7

This day in history*

Solar flares
12024M7.0
22001M6.17
32000M4.46
42022M4.0
52014M3.79
ApG
1200144G2
2200327G2
3199721G2
4201727G1
5200421G1
*since 1994

Social networks