:Product: Weekly Highlights and Forecasts
:Issued: 2001 Dec 04 2212 UT
Highlights of Solar and Geomagnetic Activity
26 November - 02 December 2001

Solar activity ranged from low to high levels with major flares
observed during 28 – 29 November. The period began with activity at
low levels due to occasional C-class subflares from a few active
regions. Activity increased to moderate levels on 27 November due to
an M2/1f flare at 27/2121 UTC from Region 9715 (N05, L = 137,
Ekc/990 on 30 November). Activity rose to high levels during 28 – 29
November due to two major flares from Region 9715, the first being
an M6/1b at 28/1635 UTC associated with a 450 sfu Tenflare, Type II
and IV radio sweeps, and a partial-halo coronal mass ejection (CME).
The second was an M5/1n at 29/1036 UTC with minor radio emission.
These flares occurred as Region 9715 gradually developed into a
large magnetically complex sunspot group with multiple magnetic
delta configurations. Region 9715 began to decay on 01 December and
produced isolated C-class flares during the rest of the period.
Region 9704 (S18, L = 270, class/area Eki/610 on 22 November), which
was the source for an impulsive X1 X-ray flare on 25 November,
crossed the west limb on 26 November. Activity decreased to moderate
levels on 30 November with isolated M-class flares from Regions 9714
(S09, L = 195, class/area Dao/240 on 01 December) and 9718 (S07, L =
086, class/area Eki/610 on 02 December). Activity rose to high
levels on 01 December due to six low-level M-class flares, also from
Regions 9714 and 9718 (for flare times and magnitudes, please refer
to the Energetic Events or Optical Flare lists). Region 9714
produced two M-class flares (with associated post-flare loop
prominence systems) on 02 December as it crossed the west limb.
Region 9718 rotated into view on 27 November and was in a minor
growth phase during the rest of the period. It was large and
moderately complex with mixed magnetic polarities evident within its
trailer spots. Other events of interest included a long-duration M4
X-ray flare at 01/1555 UTC from beyond the southeast limb.

Solar wind data were available from the NASA Advanced Composition
Explorer (ACE) spacecraft for most of the period. Wind speeds were
high (peaks to 800 km/sec) at the start of the period following a
CME passage that commenced early on 24 November. CME effects
subsided during 25 November. There were no significant disturbances
observed during the remainder of the period.

The greater than 10 MeV event that began at 22/2320 UTC ended at
27/2100 UTC. The peak for this event was 18,900 pfu at 24/0555 UTC.
There were no proton events during the rest of the period.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal levels during most of the period.

Geomagnetic field activity was at mostly quiet levels during the
period.

Forecast of Solar and Geomagnetic Activity
05 - 31 December 2001

Solar activity is expected to range from low to moderate levels.
Isolated low-level M-class flares are expected. There will be a
chance for isolated major flare activity during 05 – 10 December and
again during 21 – 31 December. Mostly low activity is expected
during 11 – 20 December.

There will be a slight chance for a proton event during 05 – 10 and
25 – 31 December.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at normal to moderate levels during most of the
period.

The geomagnetic field is expected to be at quiet to unsettled levels
during most of the period.

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