Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 27 Jul 2003

By SpaceRef Editor
July 27, 2003
Filed under , ,

Joint USAF/NOAA Report of Solar and Geophysical Activity 27 Jul 2003

SDF Number 208 Issued at 2200Z on 27 Jul 2003

IA. Analysis of Solar Active Regions and Activity from 26/2100Z
to 27/2100Z: Solar activity was at very low levels. Active regions
were quiescent through the period. Newly numbered Region 421
(S08E77) remains too close to the east limb for a detailed analysis
of its complexity.

IB. Solar Activity Forecast: Solar activity is expected to be at
predominantly very low levels. Based on SXI imagery Region 421 may
have the potential to produce C-class flares, pending further
analysis, as it has yet to fully rotate onto the visible disk.

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field was at unsettled to minor storm levels. A
recurrent high speed coronal hole stream and a sustained southward
Bz are believed responsible for the elevated activity. The solar
wind speed exceeded 800 km/s at approximately 27/0600Z. NASA/ACE
data also indicates a possible transient passage very early in the
period. The greater than 2 MeV electron fluxes at geosynchronous
orbit reached moderate levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly unsettled to active levels.
Isolated minor storm conditions are possible at both mid and high
latitudes due to the effects of the high speed solar wind for days
one and two. Day three should see a decrease in the elevated solar
wind speeds and the associated effects.

III. Event Probabilities 28 Jul-30 Jul

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

IV. Penticton 10.7 cm Flux

  • Observed 27 Jul 102
  • Predicted 28 Jul-30 Jul 110/115/115
  • 90 Day Mean 27 Jul 126

V. Geomagnetic A Indices

  • Observed Afr/Ap 26 Jul 020/026
  • Estimated Afr/Ap 27 Jul 020/030
  • Predicted Afr/Ap 28 Jul-30 Jul 020/030-020/030-012/025

VI. Geomagnetic Activity Probabilities 28 Jul-30 Jul

A. Middle Latitudes

  • Active 40/40/25
  • Minor storm 25/25/10
  • Major-severe storm 10/10/05

B. High Latitudes

  • Active 40/40/35
  • Minor storm 35/35/30
  • Major-severe storm 20/20/15

SpaceRef staff editor.