Viewing archive of Thursday, 18 September 2008
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 2008 Sep 18 2201 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 262 Issued at 2200Z on 18 Sep 2008IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z Solar activity was very low. No flares were observed
during the past 24 hours. The visible disk remained spotless.
IB. Solar Activity Forecast
Solar activity is expected to be very
low.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
The geomagnetic field was predominately quiet to unsettled. An
isolated active period was observed at Boulder between
18/0900-1200Z. Solar wind speed measured at the ACE spacecraft
showed a gradual decrease from approximately 410 km/s to 370 km/s
during the forecast period. The greater than 2 MeV electron flux at
geosynchronous orbit was at high levels today.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be predominately quiet with isolated unsettled
conditions for the next three days (19-21 September).
III. Event Probabilities 19 Sep to 21 Sep
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 18 Sep 067 Predicted 19 Sep-21 Sep 066/066/066 90 Day Mean 18 Sep 066
V. Geomagnetic A Indices
Observed Afr/Ap 17 Sep 003/003 Estimated Afr/Ap 18 Sep 005/005 Predicted Afr/Ap 19 Sep-21 Sep 005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 19 Sep to 21 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 10% |
| Minor storm | 01% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 10% |
| Minor storm | 01% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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