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 UTC
Prepared 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 1999

IA. 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 M30%30%30%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
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
Active25%25%25%
Minor storm15%15%15%
Major-severe storm15%15%15%
B. High Latitudes
Active25%25%25%
Minor storm20%20%20%
Major-severe storm15%15%15%

All times in UTC

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