:Product: Weekly Highlights and Forecasts
:Issued: 2001 Mar 20 2112 UT
Highlights of Solar and Geomagnetic Activity
12 - 18 March 2001

Solar activity decreased to mostly low levels following last week's
brief period of major flare activity from Region 9368 (N25, L = 086,
class/area Eki/610 on 08 March). This region was decaying as it
quietly crossed the west limb on 12 March. There were two sunspots
groups of note during the period: Region 9373 (S07, L = 329,
class/area Eai/320 on 12 March) and Region 9384 (N11, L = 334,
class/area Dao/120 on 16 March). Region 9373 produced C-class flares
during the period as it displayed alternate periods of growth and
decay. Region 9373 was of moderate size and magnetic complexity at
the close of the period. Region 9384 produced C-class subflares as
well, mostly during 15 - 16 March as it grew. Region 9384 stabilized
on 17 March as a moderate-sized group with a minor degree of
magnetic complexity. A full-halo CME occurred on 15 March following
a filament eruption near center disk.

Data were available from the Advanced Composition Explorer (ACE)
spacecraft for most of the period. However, interplanetary magnetic
field data was unavailable on 16 March. A coronal transient was
observed during 12 - 13 March. Transient effects were minor with
small increases in solar wind velocity and density, along with a
fairly brief southward turning of IMF Bz (maximum deflections to
minus 10 nT (GSM). Nominal solar wind conditions occurred during the
remainder of the period.

No proton events occurred.

The greater than 2 MeV electron flux at geosynchronous orbit was at
mostly normal levels.

The geomagnetic field was disturbed on 12 March as a coronal
transient passed Earth. Unsettled to active levels occurred during
the disturbance. Quiet to unsettled conditions prevailed for the
remainder of the period. Note: at issue time, a major geomagnetic
storm was in progress. Details will be provided in next week's
issue.

Forecast of Solar and Geomagnetic Activity
21 March - 16 April 2001

Activity is expected to be at mostly low to moderate levels during
the period. Best chance for isolated M-class flares will be during
21 - 22 March and again during the latter half of the forecast
period. There will also be a slight chance for a major flare during
these periods.

There will be a slight chance for a proton event during the period.

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 disturbed during 21 - 23.
Active to minor storm conditions will be possible during the
disturbance. Quiet to unsettled levels are expected for the rest of
the period, barring an Earth-directed CME.


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