Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 17 Apr 2005

By SpaceRef Editor
April 17, 2005
Filed under , ,

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Apr 17 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 107 Issued at 2200Z on 17 Apr 2005

IA. Analysis of Solar Active Regions and Activity from 16/2100Z
to 17/2100Z: Solar activity has been low. Newly numbered Region 755
(S11E76) generated three C-class events on 17 Apr, two near 1300Z
and one at 2054Z. All other regions remain steady.

IB. Solar Activity Forecast: Solar activity is expected to be low.
Region 755 has the continued potential to produce C-class activity.

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field has been at quiet to unsettled levels. The
greater than 2 MeV electron flux at geosynchronous orbit reached
high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels. There’s a chance for
isolated periods of active levels as a high-speed stream from a
small, but well defined coronal hole rotates into potentially
geoeffective range from 19 – 20 Apr.

III. Event Probabilities 18 Apr-20 Apr

  • Class M 10/15/15
  • Class X 01/01/01
  • Proton 01/01/01
  • PCAF green

IV. Penticton 10.7 cm Flux

  • Observed 17 Apr 084
  • Predicted 18 Apr-20 Apr 090/090/090
  • 90 Day Mean 17 Apr 093

V. Geomagnetic A Indices

  • Observed Afr/Ap 16 Apr 004/007
  • Estimated Afr/Ap 17 Apr 005/006
  • Predicted Afr/Ap 18 Apr-20 Apr 005/008-010/012-008/012

VI. Geomagnetic Activity Probabilities 18 Apr-20 Apr

A. Middle Latitudes

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

B. High Latitudes

  • Active 20/25/25
  • Minor storm 05/10/10
  • Major-severe storm 02/05/05

SpaceRef staff editor.