:Product: Weekly Highlights and Forecasts
:Issued: 2003 Aug 12 2212 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Environment Center
# Product description and SEC contact on the Web
# http://www.sec.noaa.gov/weekly.html
#
#                Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
04 - 10 August 2003

Solar activity ranged from very low to moderate levels.  The period
began with low level activity on 03 August and to very low levels on
04 August.  Region 424 (S18, L=290, class/area Ekc/760 on 06 August)
was the largest and most active region on the disk during the
period.  This region began the period as a beta-gamma spot group and
developed a beta-gamma-delta magnetic configuration on 06 August. 
By 07 August, Region 424’s growth phase ended and it began a steady
decay phase that continued through the end of the period.  Region
424 produced the largest event of the period, an M1/Sn on 05 August
at 1249 UTC.  This flare was associated with a weak Type II radio
sweep measuring 339 km/s.  Activity for the remainder of the period,
06 – 10 August was at low levels with the exception of 09 August
when activity dropped to very low levels.  Region 431 (S13, L=194,
class/area Eac/250 on 10 August) rotated onto the visible disk late
in the period (09 August) and has shown growth in area coverage as
well as an increase in magnetic complexity to a beta gamma
configuration.  Activity from this region has been limited to one
minor C-class flare on 10 August.

Solar wind data were available from the NASA Advanced Composition
Explorer (ACE) spacecraft for most of the summary period.  The
period began with solar wind speeds in decline from a previous
coronal hole high speed stream.  Early on 06 August, a prolonged
period of southward Bz began at 06/0200 UTC and was followed by an
increase in solar wind speed to near 550 km/s.  The solar wind data
were consistent with the arrival of a co-rotating interacting region
(CIR) and a subsequent equatorial coronal hole high speed stream. 
Wind speed increased on 07 August to near 700 km/s and up to 800
km/s on 08 August.  Wind speed slowly decreased on 09 – 10 August
down to 600 km/s.  Bz from the high speed stream was mostly
northward except for the CIR mentioned above and a period late on 07
August when it reached - 10 nT.

There were no greater than 10 MeV proton events at geosynchronous
orbit during the period.

The greater than 2 MeV electron flux at geosynchronous orbit reached
high levels on 04 – 05 August and again on 09 – 10 August.

The geomagnetic field ranged from quiet to minor storm levels.  The
period began with quiet to active conditions on 04 August and quiet
to unsettled conditions on 05 August.  On 06 August, activity
increased to isolated severe storm levels due the CIR and high speed
stream mentioned above.  Activity on 07 – 08 August reached minor
storm levels due to the period of southward Bz late on 07 August. 
High speed stream effects decreased on 09 – 10 August with quiet to
active conditions.

Forecast of Solar and Geomagnetic Activity
13 August - 08 September 2003

Solar activity is expected to range from very low to moderate levels
during the period.  Activity for most of the period is expected to
be at very low to low levels.  Region 424 has the potential for
isolated M-class activity early in the period and if Region 431
continues to develop it may produce isolated M-class activity.

No greater than 10 MeV proton events at geosynchronous orbit are
expected during the period.

The greater than 2 MeV electron flux is expected to reach high levels
on 13 –15 August, 25 August – 01 September, and again on 05 – 07
September.

The geomagnetic field is expected to range from quiet to major storm
levels during the period.  Coronal hole effects are expected to
continue on 13 August with isolated major storm levels possible.  A
large coronal hole high speed stream is due to return to a
geoeffective position and is expected to produce minor storm levels
on 22 – 29 August.