Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Feb 2005

By SpaceRef Editor
February 21, 2005
Filed under , ,

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Updated 2005 Feb 20 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 051 Issued at 2200Z on 20 Feb 2005

IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity decreased to very low levels. A long
duration B-class flare was observed at 20/1628Z from just beyond the
solar west limb. This event is believed to be from Region 732 (N08
L=188) which rotated out of view on 18 February. Region 735
(S09W58) has changed little since yesterday and remains a magnetic
beta-gamma group. Region 736 (N13W50) is a weak beta magnetic
region that was numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at
very low to low levels. Region 735 continues to show enough
complexity to possibly produce isolated C-class flare activity.

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was at predominantly quiet to unsettled levels.
An isolated active period did occur between 20/2400 and 0300Z that
appears to be due to a recurrent high speed coronal hole stream.
The coronal hole has been waning throughout the period and current
solar wind speeds have dropped to near 400 km/s. The greater than 2
MeV electron flux at geosynchronous orbit reached high levels again

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly quiet to unsettled levels throughout
the period.

III. Event Probabilities 21 Feb-23 Feb

  • Class M 10/10/10
  • Class X 01/01/01
  • Proton 01/01/01
  • PCAF green

IV. Penticton 10.7 cm Flux

  • Observed 20 Feb 096
  • Predicted 21 Feb-23 Feb 095/095/090
  • 90 Day Mean 20 Feb 101

V. Geomagnetic A Indices

  • Observed Afr/Ap 19 Feb 008/014
  • Estimated Afr/Ap 20 Feb 006/010
  • Predicted Afr/Ap 21 Feb-23 Feb 005/005-007/010-007/012

VI. Geomagnetic Activity Probabilities 21 Feb-23 Feb

A. Middle Latitudes

  • Active 15/15/15
  • Minor storm 01/01/01
  • Major-severe storm 01/01/01

B. High Latitudes

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

SpaceRef staff editor.