Viewing archive of Tuesday, 19 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 19 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 109 Issued at 2200Z on 19 Apr 2011IA. Analysis of Solar Active Regions and Activity from 18-2100Z to 19-2100Z
Solar activity has been at low levels for the past 24
hours. New Region 1195 (S16E68) rotated onto the visible disk, early
in the period, as a Dao sunspot group. Before being numbered, Region
1195 produced several C-class events off the east limb, as well as
the largest event of the past 24 hours, a C1 flare at 18/0512Z.
Region 1193 (N17W08) continues to evolve and has grown into a
beta-gamma magnetic classification.
IB. Solar Activity Forecast
Solar activity is expected to be at
low levels with a slight chance for M-class activity for the next
three days (20-22 April).
IIA. Geophysical Activity Summary 18-2100Z to 19-2100Z
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 quiet to unsettled levels with a chance for
isolated active periods for the next three days (20-22 April).
Heightened activity levels are expected due to the arrival, early on
day 1, of a coronal hole high-speed stream (CH HSS). Effects from
the CH HSS are expected to last about 2 days. Late on day 2, a
slow-moving CME is expected to become geoeffective with effects
lasting through day 3.
III. Event Probabilities 20 Apr to 22 Apr
| Class M | 15% | 15% | 15% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 19 Apr 111 Predicted 20 Apr-22 Apr 110/110/110 90 Day Mean 19 Apr 104
V. Geomagnetic A Indices
Observed Afr/Ap 18 Apr 008/010 Estimated Afr/Ap 19 Apr 005/005 Predicted Afr/Ap 20 Apr-22 Apr 010/010-010/010-010/010
VI. Geomagnetic Activity Probabilities 20 Apr to 22 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 35% | 25% | 25% |
| Minor storm | 10% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 30% | 30% | 30% |
| Minor storm | 15% | 10% | 10% |
| Major-severe storm | 05% | 01% | 01% |
All times in UTC
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