Viewing archive of Saturday, 23 October 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 Oct 23 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 296 Issued at 2200Z on 23 OCT 1999IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z SOLAR ACTIVITY WAS LOW. THE X-RAY BACKGROUND HAS
REMAINED ABOVE C-LEVEL. A VARIETY OF ACTIVE REGIONS PRODUCED SMALL
FLARES, INCLUDING REGION 8731 (N12W92), 8739 (S13E30), AND 8741
(S26E50). REGION 8741 WAS THE MOST ACTIVE AND HAS UNDERGONE
CONSIDERABLE GROWTH SINCE YESTERDAY. REGION 8739 HAS ALSO GROWN.
BOTH REGIONS CONTAIN MIXED POLARITIES. NEW REGION 8742 (N06E82) IS
ROTATING AROUND THE EAST LIMB.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. LOW-LEVEL M-CLASS ACTIVITY IS POSSIBLE IN REGIONS 8739
OR 8741.
IIA. Geophysical Activity Summary 22-2100Z to 23-2100Z
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO MINOR STORM LEVELS IN THE
WAKE OF YESTERDAY'S MAJOR STORM ACTIVITY. SOLAR WIND SPEEDS REMAINED
AT OR ABOVE 600 KM/S AND THE IMF BZ FLUCTUATED BETWEEN +/- 5 NT. THE
GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS
MODERATE TO HIGH.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE PREDOMINATELY UNSETTLED TO ACTIVE WITH ISOLATED STORM
PERIODS AS WE RECOVER FROM THE MAJOR ACTIVITY OF OCTOBER 22. FIELD
ACTIVITY MAY ALSO BE INFLUENCED OVER THE NEXT THREE DAYS BY A
CORONAL HOLE HIGH SPEED STREAM.
III. Event Probabilities 24 OCT to 26 OCT
| Class M | 30% | 30% | 30% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 23 OCT 165 Predicted 24 OCT-26 OCT 165/160/155 90 Day Mean 23 OCT 158
V. Geomagnetic A Indices
OBSERVED AFR/AP 22 OCT 045/087 ESTIMATED AFR/AP 23 OCT 020/028 PREDICTED AFR/AP 24 OCT-26 OCT 020/030-020/020-010/015
VI. Geomagnetic Activity Probabilities 24 OCT to 26 OCT
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 25% | 25% |
| Minor storm | 15% | 15% | 15% |
| Major-severe storm | 15% | 15% | 15% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 25% | 25% | 25% |
| Minor storm | 20% | 20% | 20% |
| Major-severe storm | 15% | 15% | 15% |
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