Viewing archive of Tuesday, 21 April 2009
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 2009 Apr 21 2201 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 111 Issued at 2200Z on 21 Apr 2009IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z
Solar activity was very low. No flares were observed.
New Region 1015 (N22 W65) was numbered during the period. The
region formed on the disk and is a simple Axx alpha spot group.
IB. Solar Activity Forecast
Solar activity is expected to be very
low.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was mostly quiet. Observations from the ACE
spacecraft indicated a gradual decay in wind speeds, from near 450
km/s to 390 km/s, through about 21/1100Z. Since that time, and
through the remainder of the period, wind velocities increased to
about 460 km/s.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be at quiet to unsettled levels for 22 April due to a
recurrent enhancement in solar wind velocities. On 23 - 24 April,
mostly quiet conditions are expected.
III. Event Probabilities 22 Apr to 24 Apr
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Apr 071 Predicted 22 Apr-24 Apr 070/070/070 90 Day Mean 21 Apr 070
V. Geomagnetic A Indices
Observed Afr/Ap 20 Apr 003/004 Estimated Afr/Ap 21 Apr 006/007 Predicted Afr/Ap 22 Apr-24 Apr 007/007-005/005-005/005
VI. Geomagnetic Activity Probabilities 22 Apr to 24 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 05% | 05% |
| Minor storm | 05% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 05% | 05% |
| Minor storm | 05% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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