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 UTCPrepared 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 2001IA. 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 M | 80% | 80% | 80% |
| Class X | 10% | 10% | 10% |
| Proton | 05% | 05% | 05% |
| PCAF | green | ||
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 | |||
|---|---|---|---|
| Active | 20% | 20% | 20% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 30% | 30% | 30% |
| Minor storm | 10% | 10% | 10% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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