Viewing archive of Wednesday, 27 April 2011
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 2011 Apr 27 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 117 Issued at 2200Z on 27 Apr 2011IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z Solar activity has been at low levels for the past 24
hours. New Region 1201 (N16E40), grew rapidly early in the period,
producing a C2 flare at 27/0301Z with a non-Earth directed CME. A
Type II radio sweep, with a shock velocity of 845 km/s, was also
associated with this event. Region 1201 has since decayed and is
now spotless plage. A second, back-sided CME, first visible in
LASCO C2 imagery at 27/0800Z, was also observed during the period.
Neither CME is expected to become geoeffective. Region 1199 (N21W34)
continues to grow and evolve.
IB. Solar Activity Forecast
Solar activity is expected to be at
very low to low levels for the next three days (28-30 April).
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
The geomagnetic field has been at quiet levels for the past 24 hours.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be at predominantly quiet levels for the next 2 days
(28-29 April). Unsettled to active levels are expected on day three
(30 April) as a recurrent coronal hole high-speed stream becomes
geoeffective.
III. Event Probabilities 28 Apr to 30 Apr
| Class M | 05% | 05% | 05% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 27 Apr 108 Predicted 28 Apr-30 Apr 105/105/105 90 Day Mean 27 Apr 107
V. Geomagnetic A Indices
Observed Afr/Ap 26 Apr 001/003 Estimated Afr/Ap 27 Apr 001/003 Predicted Afr/Ap 28 Apr-30 Apr 005/005-005/005-010/010
VI. Geomagnetic Activity Probabilities 28 Apr to 30 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 05% | 10% | 35% |
| Minor storm | 01% | 01% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 05% | 10% | 35% |
| Minor storm | 01% | 01% | 05% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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