Viewing archive of Sunday, 17 September 2000
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 2000 Sep 17 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 261 Issued at 2200Z on 17 SEP 2000IA. Analysis of Solar Active Regions and Activity from 16-2100Z to 17-2100Z SOLAR ACTIVITY WAS LOW. THE LARGEST FLARE OF THE PAST
DAY WAS A C5/1F AT 17/0643 UTC IN REGION 9167 (N11E69). THIS REGION
ALSO PRODUCED A NUMBER OF OTHER LESS SIGNIFICANT SUBFLARES. 9167 IS
STILL CLOSE TO THE EAST LIMB BUT APPEARS TO BE A GROWING D-TYPE
GROUP. REGION 9165 (N14W26) CONTINUES TO DECAY IN SUNSPOT AREA AND
MAGNETIC COMPLEXITY. HOWEVER, IT MANAGED TO PRODUCE SEVERAL C-CLASS
SUBFLARES, THE LARGEST OF WHICH WAS A C3/SF AT 17/0042 UTC. REGION
9166 (S14E37) ALSO PRODUCE A FEW C-CLASS FLARES AND CONTINUES TO
INCREASE IN COMPLEXITY AS IT ROTATES FURTHER ONTO THE DISK. NEW
REGION 9168 (N09E06) EMERGED.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. ADDITIONAL C-CLASS ACTIVITY IS EXPECTED IN REGIONS
9165, 9166, AND 9167. M-CLASS FLARES ARE POSSIBLE IN THESE REGIONS
AS WELL.
IIA. GEOPHYSICAL ACTIVITY SUMMARY 16/2100Z TO 17/2100Z:
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO STORM LEVELS. THE FIELD
APPEARED TO BE UNDER THE INFLUENCE OF A HIGH-SPEED CORONAL HOLE
STREAM FOR MOST OF THE DAY. ACE NEAR-REAL-TIME DATA SUGGESTS THE
ARRIVAL OF CME MATERIAL AT L1 AT ABOUT 17/1500 UTC. THIS CME MAY
HAVE BEEN ASSOCIATED WITH ACTIVITY IN REGION 9165 ON SEP 15.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE, REACHING STORM LEVELS BY SEP 19.
THE STRONGEST ACTIVITY IS EXPECTED FROM A CME RELATED TO THE M5/2B
FLARE IN REGION 9165 EARLY ON SEP 16. A HIGH-SPEED CORONAL HOLE
STREAM MAY MAINTAIN ACTIVITY LEVELS FOR A FEW DAYS AFTER THESE CMES
PASS THE EARTH.
III. Event Probabilities 18 SEP to 20 SEP
| Class M | 50% | 50% | 50% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 17 SEP 182 Predicted 18 SEP-20 SEP 185/190/190 90 Day Mean 17 SEP 177
V. Geomagnetic A Indices
OBSERVED AFR/AP 16 SEP 014/021 ESTIMATED AFR/AP 17 SEP 020/025 PREDICTED AFR/AP 18 SEP-20 SEP 020/020-040/040-030/040
VI. Geomagnetic Activity Probabilities 18 SEP to 20 SEP
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 60% | 50% | 50% |
| Minor storm | 15% | 25% | 25% |
| Major-severe storm | 05% | 25% | 25% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 75% | 25% | 25% |
| Minor storm | 15% | 30% | 30% |
| Major-severe storm | 05% | 35% | 35% |
All times in UTC
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