Viewing archive of Thursday, 2 September 1999
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 1999 Sep 02 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 245 Issued at 2200Z on 02 SEP 1999IA. Analysis of Solar Active Regions and Activity from 01-2100Z to 02-2100Z SOLAR ACTIVITY HAS BEEN LOW FOR THE PAST 24 HOURS. MOST
OF THE 8 SPOTTED REGIONS DECLINED IN WHITE LIGHT AND MAGNETIC
COMPLEXITY. HOWEVER ONE REGION EMERGED RAPIDLY NEAR N10W06 AND WAS
NUMBERED AS REGION 8687. REGION 8675 (N19W41) PRODUCED A C6/2F LONG
DURATION FLARE THAT MAXED AT 1828 UT. A FILAMENT NEAR N25W05
DISAPPEARED BETWEEN 01/1923 AND 02/0720 UT. ANOTHER DARK FILAMENT
NEAR S30W15 DISAPPEARED BETWEEN 02/0720-1527 UT IN A PARTICULARLY
INTERESTING AREA OF EVOLVING LARGE-SCALE MAGNETIC FIELDS. AN
ERUPTIVE PROMINENCE THAT COULD BE SEEN OUT TO 0.49 SOLAR RADIUS WAS
OBSERVED ON THE SOUTHEAST LIMB (S27) NEAR 1400 UT.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
FOR THE NEXT THREE DAYS. REGIONS 8681 (N21W56) AND 8675 HAVE A SMALL
PROBABILITY OF ISOLATED M-CLASS X-RAY FLARES.
IIA. Geophysical Activity Summary 01-2100Z to 02-2100Z
GEOMAGNETIC CONDITIONS HAVE RANGED BETWEEN QUIET AND ACTIVE FOR THE
LAST 24 HOURS. THE GEOMAGNETIC FIELD IS CONTINUING TO BE INFLUENCED
BY A STEADY, POSITIVE POLARITY (AWAY) SOLAR WIND STREAM OF MODERATE
SPEED (NEAR 450 KM/S). THE INTERPLANETARY MAGNETIC FIELD INTENSITY
WAS APPROXIMATELY 10 NT, AND WAS PREDOMINATELY SOUTHWARD,
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO PERSIST AT UNSETTLED TO OCCASIONALLY ACTIVE LEVELS
TOMORROW, DECREASING TOWARD GENERALLY UNSETTLED CONDITIONS BY THE
END OF THE FORECAST PERIOD. HOWEVER, DISTURBED SOLAR WIND FROM ANY
OF THE SEVERAL ERUPTIVE EVENTS OBSERVED TODAY MAY RAISE ACTIVITY TO
NEAR-STORM LEVELS ON SEPTEMBER 6 AND 7.
III. Event Probabilities 03 SEP to 05 SEP
| Class M | 30% | 20% | 20% |
| Class X | 10% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 02 SEP 157 Predicted 03 SEP-05 SEP 150/140/130 90 Day Mean 02 SEP 168
V. Geomagnetic A Indices
OBSERVED AFR/AP 01 SEP 014/022 ESTIMATED AFR/AP 02 SEP 010/012 PREDICTED AFR/AP 03 SEP-05 SEP 015/010-010/010-010/010
VI. Geomagnetic Activity Probabilities 03 SEP to 05 SEP
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 05% | 05% |
| Minor storm | 10% | 05% | 05% |
| Major-severe storm | 05% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 20% | 20% |
| Minor storm | 15% | 10% | 10% |
| Major-severe storm | 05% | 05% | 01% |
All times in UTC
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