Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 29 May 2005

By SpaceRef Editor
May 30, 2005
Filed under , ,

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 May 29 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 149 Issued at 2200Z on 29 May 2005

IA. Analysis of Solar Active Regions and Activity from 28/2100Z
to 29/2100Z: Solar activity was low. A C1.7 flare occurred at
28/2217 UTC which was probably produced by Region 769 (S08E59);
however, the full extent of this region is hard to determine due to
its proximity to the east limb. Region 767 (S09W31) has decayed to
200 millionths in area. New Region 770 (N12E00) was numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be very
low to low with a slight chance for an M-class event from Region

IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z:
The geomagnetic field was quiet to active. Heightened activity was
due to the arrival of the full halo CME observed on 26 May combined
with a coronal hole high speed stream. A shock was observed at ACE
at approximately 29/0900 UTC and a sudden impulse of 30 nT was
observed at 29/0953 UTC. Solar wind speed at ACE increased to 450
km/s during the initial shock and is now between 500 km/s and 550

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be mostly quiet to unsettled with isolated active
conditions possible on 30 May. Quiet to unsettled conditions are
expected on 31 May and 01 June.

III. Event Probabilities 30 May-01 Jun

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

IV. Penticton 10.7 cm Flux

  • Observed 29 May 093
  • Predicted 30 May-01 Jun 100/100/100
  • 90 Day Mean 29 May 092

V. Geomagnetic A Indices

  • Observed Afr/Ap 28 May 009/013
  • Estimated Afr/Ap 29 May 012/015
  • Predicted Afr/Ap 30 May-01 Jun 008/010-008/008-005/008

VI. Geomagnetic Activity Probabilities 30 May-01 Jun

A. Middle Latitudes

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

B. High Latitudes

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

SpaceRef staff editor.