Viewing archive of Sunday, 18 October 1998

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 1998 Oct 18 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 291 Issued at 2200Z on 18 OCT 1998

IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z

SOLAR ACTIVITY BECAME MODERATE WHEN REGION 8358 (N15W69) PRODUCED A M2/1N FLARE AT 18/0145Z. THIS REGION BECAME VERY ACTIVE DURING A GROWTH PERIOD THAT BEGAN WITH A C9/1F AT 17/1851Z AND ENDED AT 18/0538Z, PRODUCING ONE M-CLASS AND FIVE C-CLASS FLARES. ACTIVITY FROM THIS, AND ALL OTHER REGIONS HAVE BEEN VERY LOW SINCE. NEW REGIONS 8365 (S28E10) AND 8366 (S16E35) WERE NUMBERED TODAY BRINGING THE TOTAL TO NINE SPOT GROUPS VISIBLE IN WHITE LIGHT.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW. REGION 8358 WILL LIKELY PRODUCE FURTHER C-CLASS ACTIVITY AND STILL HAS POTENTIAL FOR AN ISOLATED M-CLASS.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE UNSETTLED TO ACTIVE WITH ISOLATED PERIODS OF MINOR STORMING IN RESPONSE TO THE CME ON 15 OCT.
III. Event Probabilities 19 OCT to 21 OCT
Class M25%15%15%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       18 OCT 126
  Predicted   19 OCT-21 OCT  130/130/135
  90 Day Mean        18 OCT 132
V. Geomagnetic A Indices
OBSERVED AFR/AP 17 OCT  009/009
ESTIMATED AFR/AP 18 OCT  012/015
PREDICTED AFR/AP 19 OCT-21 OCT  025/030-015/020-010/015
VI. Geomagnetic Activity Probabilities 19 OCT to 21 OCT
A. Middle Latitudes
Active50%25%10%
Minor storm30%15%01%
Major-severe storm10%01%01%
B. High Latitudes
Active50%30%20%
Minor storm40%20%10%
Major-severe storm10%05%01%

All times in UTC

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