Viewing archive of Tuesday, 21 May 2013
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 2013 May 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 141 Issued at 2200Z on 21 May 2013IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C1 event observed at
21/0012Z from Region 1751 (S23W57). There are currently 7 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be low with
a chance for M-class flares and a slight chance for an X-class flare on
days one, two, and three (22 May, 23 May, 24 May).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed,
as measured by the ACE spacecraft, reached a peak speed of 570 km/s at
21/1900Z. Total IMF reached 6 nT at 21/1855Z. The maximum southward
component of Bz reached -5 nT at 21/0515Z. Protons greater than 10 MeV
at geosynchronous orbit reached a peak level of 2 pfu at 20/2145Z.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at quiet to unsettled levels on days one and three (22 May, 24
May) and unsettled to active levels on day two (23 May). Protons have a
slight chance of crossing threshold on days one, two, and three (22 May,
23 May, 24 May).
III. Event Probabilities 22 May to 24 May
| Class M | 50% | 50% | 50% |
| Class X | 20% | 20% | 20% |
| Proton | 20% | 20% | 20% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 May 125 Predicted 22 May-24 May 120/120/125 90 Day Mean 21 May 121
V. Geomagnetic A Indices
Observed Afr/Ap 20 May 006/008 Estimated Afr/Ap 21 May 007/008 Predicted Afr/Ap 22 May-24 May 011/012-012/015-007/008
VI. Geomagnetic Activity Probabilities 22 May to 24 May
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 30% | 15% |
| Minor storm | 05% | 10% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 15% |
| Minor storm | 25% | 30% | 25% |
| Major-severe storm | 30% | 40% | 20% |
All times in UTC
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