Viewing archive of Saturday, 11 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 11 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 131 Issued at 2200Z on 11 May 2002
IA. Analysis of Solar Active Regions and Activity from 10-2100Z to 11-2100Z
Solar activity was at moderate levels. Region 9937
(S09W38) produced an M1/Sf flare at 11/1132 UTC with an associated
Type II radio sweep of 415 km/s and minor discrete radio bursts.
Increased magnetic complexity is apparent in this region with the
hint of a delta forming in the dominant spot, seen in the trailing
portion of spot cluster. Region 9934 (S17W59) was fairly active
today, producing multiple C-class flares. The largest was a C3/Sf
flare occurring at 11/1738 UTC. This region remains the most
complex region on the disk. New Region 9950 (S06E44) produced a
C2/Sf flare at 11/1650 UTC. Region 9949 (S16W06) is also a newly
numbered region.
IB. Solar Activity Forecast
Solar activity is expected to be low
to moderate. Regions 9934 and 9937 are both complex enough to
produced M-class flare activity.
IIA. Geophysical Activity Summary 10-2100Z to 11-2100Z
The geomagnetic field was at quiet to major storm levels. Data from
the Advanced Composition Explorer (ACE) showed an increase in the
solar wind speed from roughly 350 to 450 km/s beginning at
approximately 11/0915 UTC. The north-south component of the
interplanetary magnetic field remained strongly negative for several
hours thereafter. A sudden impulse of 41 nT was observed at the
Boulder Magnetometer at 11/1028 UTC. Major storm conditions were
observed at high latitudes from 11/1100 through 11/1800 UTC.
Uncertain as to the source(s) of the activity, although multiple
CME's were seen in SOHO/LASCO imagery on the eighth and ninth.
Source regions for CME's believed to have been from both the east
and west limbs.
IIB. Geophysical Activity Forecast
The geomagnetic field activity
is expected to be at predominantly quiet to unsettled levels.
Isolated minor storm conditions may occur on day three of the
forecast due to the M1/Sf flare that occurred at 11/1132 UTC.
III. Event Probabilities 12 May to 14 May
Class M | 60% | 60% | 50% |
Class X | 15% | 15% | 05% |
Proton | 10% | 10% | 01% |
PCAF | green
|
IV. Penticton 10.7 cm Flux
Observed 11 May 188
Predicted 12 May-14 May 190/195/190
90 Day Mean 11 May 187
V. Geomagnetic A Indices
Observed Afr/Ap 10 May 019/017
Estimated Afr/Ap 11 May 035/040
Predicted Afr/Ap 12 May-14 May 012/015-008/010-012/012
VI. Geomagnetic Activity Probabilities 12 May to 14 May
A. Middle Latitudes |
Active | 25% | 20% | 25% |
Minor storm | 05% | 05% | 05% |
Major-severe storm | 01% | 01% | 01% |
B. High Latitudes |
Active | 30% | 20% | 30% |
Minor storm | 10% | 05% | 10% |
Major-severe storm | 05% | 01% | 05% |
All times in UTC
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