Viewing archive of Friday, 18 February 2005

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 2005 Feb 18 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 049 Issued at 2200Z on 18 Feb 2005

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

Solar activity was low. Regions 732 (N15W90) and 735 (S09W32) were responsible for several low level C-class flares. Region 732 produced the largest C-flare; a C2.3 at 17/2344Z.
IB. Solar Activity Forecast
Solar activity is expected to be low. Region 735 is still capable of producing C-class events.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
The geomagnetic field was at quiet to minor storm levels. Activity was due to the effects of a high speed stream from a geoeffective coronal hole. Solar wind speed at ACE showed an increase to approximately 600 km/s by 18/1600Z and then decreased slightly to 550 km/s by the end of the period.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be unsettled to active with the possibility of isolated minor storm levels on 19 February due to the arrival of the CME observed on LASCO imagery on 17 February. Expect quiet to active conditions on 20 February and quiet to unsettled conditions on 21 February.
III. Event Probabilities 19 Feb to 21 Feb
Class M15%15%15%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       18 Feb 104
  Predicted   19 Feb-21 Feb  100/100/095
  90 Day Mean        18 Feb 101
V. Geomagnetic A Indices
  Observed Afr/Ap 17 Feb  007/006
  Estimated     Afr/Ap 18 Feb  017/027
  Predicted    Afr/Ap 19 Feb-21 Feb  015/030-012/015-010/008
VI. Geomagnetic Activity Probabilities 19 Feb to 21 Feb
A. Middle Latitudes
Minor storm15%15%10%
Major-severe storm10%05%05%
B. High Latitudes
Minor storm30%15%10%
Major-severe storm15%10%01%

All times in UTC

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