Viewing archive of Tuesday, 21 April 2015
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 2015 Apr 21 2200 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 2015IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity has been at high levels for the past 24 hours.
The largest solar event of the period was a M4 event observed at
21/1545Z from Region 2322 (N11W87). There are currently 9 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (22 Apr, 23 Apr,
24 Apr).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic
field has been at unsettled to active levels for the past 24 hours.
Solar wind speed, as measured by the ACE spacecraft, reached a peak
speed of 628 km/s at 21/0632Z. Total IMF reached 14 nT at 20/2127Z. The
maximum southward component of Bz reached -7 nT at 21/0249Z. Electrons
greater than 2 MeV at geosynchronous orbit reached a peak level of 1433
pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (22 Apr), quiet to
active levels on day two (23 Apr) and quiet levels on day three (24
Apr).
III. Event Probabilities 22 Apr to 24 Apr
| Class M | 30% | 30% | 30% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Apr 154 Predicted 22 Apr-24 Apr 155/160/160 90 Day Mean 21 Apr 130
V. Geomagnetic A Indices
Observed Afr/Ap 20 Apr 009/011 Estimated Afr/Ap 21 Apr 020/031 Predicted Afr/Ap 22 Apr-24 Apr 019/025-015/015-007/008
VI. Geomagnetic Activity Probabilities 22 Apr to 24 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 45% | 30% | 20% |
| Minor storm | 25% | 05% | 05% |
| Major-severe storm | 05% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 05% | 15% | 15% |
| Minor storm | 20% | 30% | 25% |
| Major-severe storm | 65% | 35% | 25% |
All times in UTC
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