Viewing archive of Tuesday, 21 April 2009

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 2009 Apr 21 2201 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 111 Issued at 2200Z on 21 Apr 2009

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

Solar activity was very low. No flares were observed. New Region 1015 (N22 W65) was numbered during the period. The region formed on the disk and is a simple Axx alpha spot group.
IB. Solar Activity Forecast
Solar activity is expected to be very low.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was mostly quiet. Observations from the ACE spacecraft indicated a gradual decay in wind speeds, from near 450 km/s to 390 km/s, through about 21/1100Z. Since that time, and through the remainder of the period, wind velocities increased to about 460 km/s.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to unsettled levels for 22 April due to a recurrent enhancement in solar wind velocities. On 23 - 24 April, mostly quiet conditions are expected.
III. Event Probabilities 22 Apr to 24 Apr
Class M01%01%01%
Class X01%01%01%
Proton01%01%01%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       21 Apr 071
  Predicted   22 Apr-24 Apr  070/070/070
  90 Day Mean        21 Apr 070
V. Geomagnetic A Indices
  Observed Afr/Ap 20 Apr  003/004
  Estimated     Afr/Ap 21 Apr  006/007
  Predicted    Afr/Ap 22 Apr-24 Apr  007/007-005/005-005/005
VI. Geomagnetic Activity Probabilities 22 Apr to 24 Apr
A. Middle Latitudes
Active10%05%05%
Minor storm05%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Active10%05%05%
Minor storm05%01%01%
Major-severe storm01%01%01%

All times in UTC

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