Viewing archive of Wednesday, 27 April 2011

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 2011 Apr 27 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 117 Issued at 2200Z on 27 Apr 2011

IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z

Solar activity has been at low levels for the past 24 hours. New Region 1201 (N16E40), grew rapidly early in the period, producing a C2 flare at 27/0301Z with a non-Earth directed CME. A Type II radio sweep, with a shock velocity of 845 km/s, was also associated with this event. Region 1201 has since decayed and is now spotless plage. A second, back-sided CME, first visible in LASCO C2 imagery at 27/0800Z, was also observed during the period. Neither CME is expected to become geoeffective. Region 1199 (N21W34) continues to grow and evolve.
IB. Solar Activity Forecast
Solar activity is expected to be at very low to low levels for the next three days (28-30 April).
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
The geomagnetic field has been at quiet levels for the past 24 hours.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at predominantly quiet levels for the next 2 days (28-29 April). Unsettled to active levels are expected on day three (30 April) as a recurrent coronal hole high-speed stream becomes geoeffective.
III. Event Probabilities 28 Apr to 30 Apr
Class M05%05%05%
Class X01%01%01%
Proton01%01%01%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       27 Apr 108
  Predicted   28 Apr-30 Apr  105/105/105
  90 Day Mean        27 Apr 107
V. Geomagnetic A Indices
  Observed Afr/Ap 26 Apr  001/003
  Estimated     Afr/Ap 27 Apr  001/003
  Predicted    Afr/Ap 28 Apr-30 Apr  005/005-005/005-010/010
VI. Geomagnetic Activity Probabilities 28 Apr to 30 Apr
A. Middle Latitudes
Active05%10%35%
Minor storm01%01%05%
Major-severe storm01%01%01%
B. High Latitudes
Active05%10%35%
Minor storm01%01%05%
Major-severe storm01%01%01%

All times in UTC

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