Viewing archive of Monday, 27 May 2002
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 2002 May 27 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 147 Issued at 2200Z on 27 May 2002
IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z
Solar activity increased to moderate levels. Region
9957 (N10W73) produced an M2/2f flare at 27/1810 UTC associated with
minor discrete radio emission. Gradual decay may have continued in
this region, but it was difficult to tell given limb foreshortening
effects. However, it appeared that a weak delta persisted within its
northern cluster of spots. Region 9961 (S22W30) produced isolated
subflares as it continued to decay. Region 9970 (N05E41) appeared to
stabilize as a simply-structured D-type spot group. Active surging
and subflare activity was observed on the southeast limb near SE17.
This limb activity may indicate the active return of old Region 9934
(S16, L = 211). A filament erupted from the northeast quadrant
around midday. The eruption was associated with C2 X-ray event and a
CME off the northeast limb. The CME did not appear to be Earth
directed.
IB. Solar Activity Forecast
Solar activity is expected to be low
to moderate. There is a fair chance for an isolated M-class flare
during the period. There is a slight chance for a major flare as
well.
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
Geomagnetic field activity increased to quiet to active levels with
minor storm conditions observed at some high latitude stations. This
activity was likely due to coronal hole effects. ACE solar wind data
indicated a gradual rise in velocities during the period with peak
velocities in the 700 to 800 km/sec range.
IIB. Geophysical Activity Forecast
Quiet to active conditions are
expected during the first half of the period. Quiet to unsettled
conditions are expected during the remainder of the period. There is
a slight chance for a proton event until 29 May.
III. Event Probabilities 28 May to 30 May
Class M | 40% | 40% | 40% |
Class X | 05% | 05% | 01% |
Proton | 05% | 05% | 01% |
PCAF | green
|
IV. Penticton 10.7 cm Flux
Observed 27 May 187
Predicted 28 May-30 May 180/180/180
90 Day Mean 27 May 183
V. Geomagnetic A Indices
Observed Afr/Ap 26 May 009/010
Estimated Afr/Ap 27 May 017/025
Predicted Afr/Ap 28 May-30 May 012/012-008/008-008/008
VI. Geomagnetic Activity Probabilities 28 May to 30 May
A. Middle Latitudes |
Active | 35% | 30% | 25% |
Minor storm | 15% | 10% | 10% |
Major-severe storm | 01% | 01% | 01% |
B. High Latitudes |
Active | 40% | 35% | 30% |
Minor storm | 20% | 12% | 12% |
Major-severe storm | 01% | 01% | 01% |
All times in UTC
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