Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 11 Aug 2004

By SpaceRef Editor
August 12, 2004
Filed under , ,

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

Updated 2004 Aug 11 2200 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 224 Issued at 2200Z on 11 Aug 2004

IA. Analysis of Solar Active Regions and Activity from 10/2100Z
to 11/2100Z: Solar activity was low. Today’s activity consisted of
numerous C-class flares, predominantly from Region 656 (S13E03). The
largest event of the day was a C7/Sf from 656 at 1141 UTC. Region
656 continues to grow and is nearly 1000 millionths in area. The
group continues to have a magnetic delta classification. A slow,
faint CME was seen in LASCO off the south limb yesterday, beginning
at about 10/1854 UTC in C2 imagery. The CME was associated with
surge activity and a subsequent EIT wave that was observed just
north of 656 and east of central meridian.

IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate. C-flares should continue and there is a good chance for
an isolated M-class event during the next three days. There is also
a slight chance for a major flare event from 656. Background levels
are expected to increase tomorrow with the return of old Region 652
(N07, Carrington = 347).

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z:
The geomagnetic field ranged from quiet to active levels. Solar wind
data show the continuing influence of a high-speed coronal hole wind
stream. The greater than 2 MeV electron fluxes reached high levels
during the past 24 hours.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be generally unsettled with a chance for isolated active
periods for the next two days (12-13 August). Conditions are
expected to be unsettled to active on the 3rd day (14 August) with
the arrival of weak transient flow from yesterday’s CME.

III. Event Probabilities 12 Aug-14 Aug

  • Class M 55/55/55
  • Class X 10/10/10
  • Proton 10/10/10
  • PCAF green

IV. Penticton 10.7 cm Flux

  • Observed 11 Aug 131
  • Predicted 12 Aug-14 Aug 140/145/150
  • 90 Day Mean 11 Aug 107

V. Geomagnetic A Indices

  • Observed Afr/Ap 10 Aug 012/014
  • Estimated Afr/Ap 11 Aug 012/013
  • Predicted Afr/Ap 12 Aug-14 Aug 010/010-010/010-015/012

VI. Geomagnetic Activity Probabilities 12 Aug-14 Aug

A. Middle Latitudes

  • Active 30/30/35
  • Minor storm 15/15/20
  • Major-severe storm 05/05/05

B. High Latitudes

  • Active 35/35/40
  • Minor storm 15/15/20
  • Major-severe storm 05/05/05

SpaceRef staff editor.