Viewing archive of Thursday, 18 October 2001

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 2001 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 2001

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

Solar activity was at low levels. The first half of the day produced multiple low level C-class flares that were not optically correlated. At 18/1350 UTC, Region 9658 (S14W48) produced a C6/1n flare and associated radio enhancements. White light analysis of this region shows a slight decay in areal coverage of spots, though it remains a beta-gamma magnetic class group. Region 9661 (N16W23) followed with a C4/Sf flare at 18/1609 UTC and continues to show the potential to produce much more significant activity. This region has shown a small decay in areal coverage of spot group from yesterday, although it still continues to be a large, magnetically complex region. New Region 9672 (S21E69) produced the largest flare of the day, a C8/Sf flare that occurred at 18/1905 UTC. This region may very well be old Region 9632 which currently appears to have not fully rotated onto disk. Two new Regions were numbered today, 9672 and 9673 (N03E73).
IB. Solar Activity Forecast
Solar activity is expected to be at low to moderate levels. There are several regions on the disk that are capable of producing M-class or isolated major flares, the most noteworthy being Region 9661.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
The geomagnetic field was at quiet to unsettled levels.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to remain at quiet to unsettled levels through forecast period, barring the occurrence of an earth-directed CME. High latitudes may experience isolated periods of active conditions during days one and two.
III. Event Probabilities 19 Oct to 21 Oct
Class M60%60%60%
Class X10%10%10%
Proton05%05%05%
PCAFyellow
IV. Penticton 10.7 cm Flux
  Observed       18 Oct 229
  Predicted   19 Oct-21 Oct  235/240/245
  90 Day Mean        18 Oct 188
V. Geomagnetic A Indices
  Observed Afr/Ap 17 Oct  002/004
  Estimated     Afr/Ap 18 Oct  005/006
  Predicted    Afr/Ap 19 Oct-21 Oct  005/010-005/010-008/008
VI. Geomagnetic Activity Probabilities 19 Oct to 21 Oct
A. Middle Latitudes
Active15%15%20%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active20%20%20%
Minor storm05%05%05%
Major-severe storm01%01%01%

All times in UTC

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