Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 07 Sep 2003

By SpaceRef Editor

September 7, 2003

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

SDF Number 250 Issued at 2200Z on 07 Sep 2003

IA. Analysis of Solar Active Regions and Activity from 06/2100Z
to 07/2100Z: Solar activity was low. A long-duration C5 flare
occurred at 07/1407Z in Region 450 (S17W63). This flare was
characterized in H-alpha imagery by several prolonged bright kernels
in ribbon form along a thin NW-SE filament. This event appeared to
trigger a large 19 degree filament eruption near S38W18. Minor
centimetric radio bursts also accompanied this event, and LASCO
imagery revealed a large CME in progress. The X-ray flux was still
considerably enhanced by the end of the period. Region 450 is a
small, simple beta group in decay. The remaining active regions
were either stable or in decay.

IB. Solar Activity Forecast: Solar activity is expected to be low
to very low. The current X-ray flux levels are elevated following
today’s eruption, but are expected to return to the pre-flare
background level early in the period. Very isolated low C-class
flares are possible.

IIA. Geophysical Activity Summary 06/2100Z to 07/2100Z:
The geomagnetic field was quiet to unsettled. Solar wind speed has
declined to below 450 km/s. The greater than 2 MeV electron flux at
geosynchronous orbit was at high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to continue at quiet to unsettled levels through day one. A
recurring high speed coronal hole stream will likely produce active
to minor storm periods on days two and three. Activity on day three
may be further enhanced by transient material from today’s CME off
the SW limb.

III. Event Probabilities 08 Sep-10 Sep