Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Apr 2008

By SpaceRef Editor
April 21, 2008
Filed under , , ,

Product: Report of Solar-Geophysical Activity
Issued: 2008 Apr 20 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 111 Issued at 2200Z on 20 Apr 2008

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was very low. Region 991 (S10E15) decayed to a spotless plage.

IB. Solar Activity Forecast: Solar activity is expected to remain very low.

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was quiet to unsettled.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to begin mostly quiet, increasing to unsettled to active on the second and third days of the forecast period as a recurrent coronal hole high speed stream becomes geoeffective. There is a chance geomagnetic field activity will reach minor storm levels at high latitudes.

III. Event Probabilities 21 Apr-23 Apr

  • Class M 01/01/01
  • Class X 01/01/01
  • Proton 01/01/01
  • PCAF Green

IV. Penticton 10.7 cm Flux

  • Observed 20 Apr 071
  • Predicted 21 Apr-23 Apr 075/080/080
  • 90 Day Mean 20 Apr 072

V. Geomagnetic A Indices

  • Observed Afr/Ap 19 Apr 006/005
  • Estimated Afr/Ap 20 Apr 005/005
  • Predicted Afr/Ap 21 Apr-23 Apr 005/005-008/008-015/015

VI. Geomagnetic Activity Probabilities 21 Apr-23 Apr

A. Middle Latitudes

  • Active 10/20/25
  • Minor storm 05/10/15
  • Major-severe storm 01/05/10

B. High Latitudes

  • Active 10/25/30
  • Minor storm 05/10/15
  • Major-severe storm 01/05/10

SpaceRef staff editor.