Viewing archive of Saturday, 21 July 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 Jul 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 202 Issued at 2200Z on 21 Jul 2001IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z
Solar activity has been low. Region 9543 (S23W06)
produced today's largest flare, a C6/Sf at 0508 UTC. Region 9543
continues to be the largest group on the disk and is growing slowly.
Region 9548 (N16E09) also showed growth but was stable. Region 9545
(N09W43) showed newly emerging magnetic flux in the middle of the
old fields, and exhibited occasional plage fluctuations, but no
flare-level activity.
IB. Solar Activity Forecast
Solar activity is expected to be
predominantly low. There is, however, a slight chance for an
isolated M-class event.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to unsettled. The greater than 2 MeV
electron fluxes attained high levels during the past 24 hours.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be quiet to unsettled for the next three days. There is
a possibility for a small increase in activity on the third day in
response to a small but favorably positioned coronal hole.
III. Event Probabilities 22 Jul to 24 Jul
| Class M | 25% | 25% | 25% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Jul 139 Predicted 22 Jul-24 Jul 140/140/135 90 Day Mean 21 Jul 157
V. Geomagnetic A Indices
Observed Afr/Ap 20 Jul 008/008 Estimated Afr/Ap 21 Jul 005/008 Predicted Afr/Ap 22 Jul-24 Jul 007/008-007/010-012/015
VI. Geomagnetic Activity Probabilities 22 Jul to 24 Jul
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 20% | 35% |
| Minor storm | 10% | 10% | 20% |
| Major-severe storm | 05% | 05% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 25% | 25% | 35% |
| Minor storm | 10% | 10% | 20% |
| Major-severe storm | 05% | 05% | 10% |
All times in UTC
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