Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 25 May 2003

By SpaceRef Editor
May 25, 2003
Filed under ,

SDF Number 145 Issued at 2200Z on 25 May 2003

IA. Analysis of Solar Active Regions and Activity from 24/2100Z
to 25/2100Z: Solar activity was at low levels. Region 368 (S33E37)
produced the largest event of the period, a C3.0/Sf flare that
occurred at 25/1754Z. This region exhibits a simple Hax alpha
magnetic structure. Region 365 (S08E08) has shown rapid growth
throughout the period in penumbral coverage and magnetic complexity.
Late in the period this region produced its first reported flare, a
B5.2 x-ray flare occurring at 25/2036Z. No new regions were
numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at
low levels. Region 365 has become capable of producing C-class
flares, if growth continues at this rate an isolated M-class flare
may be a possibility over the next 24-48 hours.

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z:
The geomagnetic field was at quiet to minor storm levels. An
oscillating Bz component of the interplanetary magnetic field
allowed for two consecutive periods of minor storm conditions at
both the middle and high latitudes during local nighttime hours.
Elevated conditions are due to a high speed stream coronal hole.
The greater than 2 MeV electron fluxes at geosynchronous orbit
reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly active levels through the forecast
period. Minor storm conditions are possible especially at local
nighttime hours. Isolated major storm intervals are possible on day
two of the period. The elevated activity is expected in
anticipation of yet another recurrent high speed stream coronal

III. Event Probabilities 26 May-28 May

  • Class M 15/15/15
  • Class X 01/01/01
  • Proton 01/01/01
  • PCAF Green

IV. Penticton 10.7 cm Flux

  • Observed 25 May 121
  • Predicted 26 May-28 May 125/125/120
  • 90 Day Mean 25 May 125

V. Geomagnetic A Indices

  • Observed Afr/Ap 24 May 014/022
  • Estimated Afr/Ap 25 May 020/020
  • Predicted Afr/Ap 26 May-28 May 020/025-025/030-020/025

VI. Geomagnetic Activity Probabilities 26 May-28 May

A. Middle Latitudes

  • Active 40/45/40
  • Minor storm 20/25/20
  • Major-severe storm 10/15/10

B. High Latitudes

  • Active 45/50/45
  • Minor storm 25/25/25
  • Major-severe storm 10/15/10

SpaceRef staff editor.