:Product: Weekly Highlights and Forecasts
:Issued: 2002 Dec 03 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
25 November - 01 December 2002

Solar activity during the summary period has been low.  The largest
event was a C8/Sf flare on 28 November from Region 198 (S18, L=105,
class/area Fki/640 on 18 November).  Region 198 was in a gradual
decay phase during the summary period and rotated beyond the west
limb on 29 November.  On 27-29 November, new Region 207 (S19, L=320,
class/area Eao/430 on 29 November) produced a number of minor
C-class flares and sub-flares.  This region grew rapidly when it
first rotated onto the visible disk but has become relatively stable
by the end of the summary period.  On 28 November, Region 208 (N10,
L=288, class/area Dao/210 on 30 November) rotated onto the disk and
has shown signs of polarity mixing in the leader spot.

Solar wind data were available from the NASA Advanced Composition
Explorer (ACE) spacecraft for most of the summary period.  Late on
26 November, an interplanetary shock was observed by the ACE
spacecraft producing a –27 nT deflection in the Bz component of the
interplanetary magnetic field.  A corresponding increase in solar
wind velocity to near 600 km/s was also recorded.  The source of
this shock was most likely the 33-degree disappearing solar filament
with an associated partial halo CME on 24 November.

The greater than 10 MeV protons at geo-synchronous orbit were at
background levels for most of the summary period.  A slight
enhancement in proton flux to near 1 pfu was observed on 25-27
November.

The greater than 2 MeV electron flux at geo-synchronous orbit reached
high levels on 25 - 26 November and again on 29 November – 01
December.

The geomagnetic field was at quiet to active levels with one period
of isolated minor storm condition and an isolated major storm
condition at the higher latitudes.  The interplanetary shock on 26
November resulted in an 18 nT sudden impulse at 26/2150 UTC, as
measured by the Boulder magnetometer.  The result of the sudden
impulse was active to major storm conditions at high latitudes and
active to minor storm conditions on the planetary indices. 
Unsettled to active conditions occurred on 29 November – 01 December
due to effects from a recurring coronal hole.

Forecast of Solar and Geomagnetic Activity
04 - 30 December 2002

Solar activity is expected to be low to moderate.  Region 208 has the
potential for minor M-class activity early in the forecast period. 
Old Region 192 (N12, L=234) and old Region 191 (S18, L=203) are due
to return to the visible disk at the beginning of the period and may
produce moderate activity during the first half of the forecast
period.

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 04-07 December, 10-12 December,
20-21 December and 29-30 December due to recurring coronal holes.

The geomagnetic field is expected to be at quiet to active levels
during the forecast period.  Weak recurring coronal holes are
expected on 07-09 December and 26-28 December with resulting
unsettled to isolated active conditions.  A stronger coronal hole is
due to return to a geo-effective position on 18-19 December and is
expected to result in active to isolated minor storm conditions.


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