Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 13 Sep 2004

By SpaceRef Editor

September 13, 2004

Filed under Space Weather Prediction Center (NOAA), Space Weather Solar-Geophysical Activity, US

Space Environment Center and the U.S. Air Force.
Updated 2004 Sep 13 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 257 Issued at 2200Z on 13 Sep 2004

IA. Analysis of Solar Active Regions and Activity from 12/2100Z
to 13/2100Z: Solar activity has been low. A C1.1 X-ray flare
occurred from Region 667 (S10W85) at 12/2227 UTC. A C1.0 flare
occurred from Region 669 (S04W81) at 13/0008 UTC. A C1.4 flare
occurred from Region 672 (N04E22) at 1339 UTC. No significant
development was observed from regions on the visible disk. No new
regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate. Isolated M-class flares from Region 672 are possible.

IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z:
The geomagnetic field has been quiet to unsettled. A shock passage
was observed at ACE at approximately 13/2035 UTC. Magnetic field at
ACE was observed to increase significantly to over 20 nT at the time
of the shock arrival at ACE, although Bz remained about zero. A 24
nT sudden impulse was observed at 2003 UTC. A 10 MeV proton event
occurred at 2005 UTC in association with the sudden impulse.
Unsettled magnetic conditions were observed subsequent to the sudden
impulse.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at minor to major storming levels on 14 September,
due to the effects of a CME arrival. Conditions should subside to
quiet to active levels on 15 and 16 of September, although isolated
minor storm conditions are possible on those days from the effects
of a geoeffective coronal hole.

III. Event Probabilities 14 Sep-16 Sep