:Product: Weekly Highlights and Forecasts
:Issued: 2002 Oct 29 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
21 - 27 October 2002

Solar activity ranged from low to moderate levels.  Moderate levels
were observed on 22 October and again on 25 October.  The largest
event was a long duration M1.5/1f at 25/1747 UTC from Region 162
(N26, L=121, area/class 1120/Fki on 23 October).  Associated with
this event was a Type II radio sweep, measuring 368 km/s.  Region
162 was the most significant spot group on the visible disk during
the summary period.  On 22 October, the region developed a magnetic
beta-gamma-delta configuration in the intermediate spots.  Region
162 produced an M1 flare on 22 October and a number of C-class
events throughout the period.  In the latter half of the period,
Region 162 entered a slight decay phase.

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 velocity decreasing from 600 km/s on 21
October to 400 km/s on 23 October.  A large positive polarity
coronal hole reached a geo-effective position on 24 October
resulting in a rapid increase in solar wind velocity to near 800
km/s.  Solar wind velocity gradually decreased to 600 km/s by the
end of the day on 26 October.  The corresponding Bz component of the
IMF was at an average value of –5nT on 24 October and –3 nT on 25-27
October.

There were no greater than 10 MeV proton events at geo-synchronous
orbit during the summary period.

The greater than 2 MeV electron flux at geo-synchronous orbit was at
normal to high levels.  High levels were observed on 21-23 October
and again on 26-27 October.

The geomagnetic field was at quiet to major storm levels.  Activity
reached major storm levels on 24-25 October due to the coronal hole
effects mentioned above.   Minor storm levels were reached on 26
October and active levels reached on 27 October due to the
continued, but subsiding coronal hole effects.

Forecast of Solar and Geomagnetic Activity
30 October - 25 November 2002

Solar activity is expected be low to moderate.  Region 162 is
expected to produce occasional M-class flares until it rotates
beyond the western limb on 31 October.

There is a slight chance of a greater than 10 MeV proton event during
the forecast period.

The greater than 2 MeV electron flux at geo-synchronous orbit is
expected to reach event threshold on 30 October, on 05-06 November,
and again on 22-25 November due to coronal hole effects.

The geomagnetic field is expected to be at quiet to unsettled levels.
Active to minor storm conditions are possible on 03-04 November and
again on 20-23 November due to coronal hole effects.

.