Viewing archive of Friday, 28 September 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 Sep 28 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 271 Issued at 2200Z on 28 Sep 2001

IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z

Solar activity has been moderate. There were three M-class events observed during the past 24 hours. The first of these was an M3/2n from Region 9636 (N14E13) at 0830 UTC, which was associated with type II and type IV sweeps and a partial halo CME that appeared to be centered over the east limb. The second was an M2/1n from Region 9628 (S18W48) at 1014 UTC which was associated with a CME that was centered over the southwest limb. The 3rd was an M1/1f from Region 9637 (S15E18) at 1926 UTC. Regions 9628 and 9632 (S18W33) continue to dominate the disk in sunspot area and still maintain magnetic delta configurations. 9628 is showing some growth in the northern portion of the region. Region 9632 has been remarkably quiet, but continues to show a strong delta along an East-West inversion line. Region 9636 seems to be decaying slightly, but has a fairly complicated magnetic structure (gamma magnetic class).
IB. Solar Activity Forecast
Solar activity is expected to be moderate to high. Regions 9636, 9637, 9632 and 9628 all are capable of producing additional M-class level activity. Regions 9628 and 9632 have a fair chance for producing an isolated major flare event sometime during the next three days.
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
The geomagnetic field was quiet to unsettled during the past 24 hours. The greater than 10 MeV proton event that began at 24/1215 UTC continues in progress as the flux levels declined slowly. The flux level at forecast issue time was 94 pfu. The greater than 2 MeV electrons attained high levels during the past 24 hours.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be unsettled to slightly active during the next 48 hours. The influence of a favorably positioned coronal hole is expected to increase activity levels slightly. In addition, there is a possibility for some active conditions on the third day as the result of a glancing blow from either of today's CME events. The greater than 10 MeV proton event is expected to end sometime in the next 24-36 hours.
III. Event Probabilities 29 Sep to 01 Oct
Class M80%80%80%
Class X30%30%30%
Proton99%30%30%
PCAFin progress
IV. Penticton 10.7 cm Flux
  Observed       28 Sep 266
  Predicted   29 Sep-01 Oct  260/260/255
  90 Day Mean        28 Sep 174
V. Geomagnetic A Indices
  Observed Afr/Ap 27 Sep  009/010
  Estimated     Afr/Ap 28 Sep  013/015
  Predicted    Afr/Ap 29 Sep-01 Oct  015/015-015/018-020/018
VI. Geomagnetic Activity Probabilities 29 Sep to 01 Oct
A. Middle Latitudes
Active25%25%20%
Minor storm20%20%30%
Major-severe storm20%20%25%
B. High Latitudes
Active30%30%25%
Minor storm25%25%35%
Major-severe storm20%20%30%

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