:Product: Weekly Highlights and Forecasts
:Issued: 2003 Mar 18 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
10 - 16 March 2003

Solar activity was at very low to low levels.   On 10 – 11 March,
activity was at low levels due to activity from Region 306 (N07,
L=080, class/area Dko/640 on 15 March) and Region 304 (S11, L=168,
class/area Dao/70 on 09 March).  Region 306 developed a beta-gamma
magnetic configuration on 13 March and has exhibited steady growth
throughout the period.   Activity was very low on 12 and 14 March
and low levels on 13 March due to a minor C-flare.  A B9.2 X-ray
enhancement on 14 March at 1825 UTC was most likely due to a
disappearing solar filament. The western most 30 degrees of a large
southwest filament lifted off at 1730 UTC and was associated with a
CME. The most significant region during the period was Region 314
(S14, L=60, class/area Eki/380 on 16 March).  This region appeared
on the visible disk on 14 March and has been in a rapid growth phase
since.  Area coverage has increased to 380 millionths and on 16
March the region developed a beta-gamma-delta magnetic
configuration.  Activity on 15 and 16 March was at low levels due to
C-class flares from Region 314.  The largest event of the period was
a C8.4/Sf from Region 314 on 15 March at 2016 UTC.  At the time of
this report (18 March) Region 314 continues its rapid growth and has
produced two M-class and two X-class flares

Solar wind data were available from the NASA Advanced Composition
Explorer (ACE) spacecraft for most of the summary period.  Solar
wind velocity was relatively low early in the period.  Solar wind
velocity remained low until late on 11 March when the NASA/ACE
spacecraft detected a sector boundary crossing.  The new away sector
was marked by an increase in solar wind velocity to 450 – 500 km/s. 
On 12 – 13 March, velocity was steady near 450 km/s and the Bz
component of the interplanetary magnetic field was averaging between
+5 and –5 nT.  On 14 March solar wind velocity increased to over 600
km/s marking the onset of a transequatorial coronal hole and high
speed stream.  By the close of the period on 16 March, solar wind
velocity was over 700 km/s and continuing a gradual rise.

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 reached
high levels on 10 –13 March and again on 15 – 16 March.

The geomagnetic field has been at quiet to major storm levels. 
Activity on 10 – 13 March was quiet to active with the most
disturbed levels associated with periods of southward Bz.  On 14
March isolated major storm levels were observed and on 15 – 16 March
unsettled to minor storm levels were observed, all due to effects
from the large transequatorial coronal hole.

Forecast of Solar and Geomagnetic Activity
19 March - 14 April 2003

Solar activity is expected to be at low to moderate levels with a
continued chance of high levels of activity.  Region 314 is expected
to have X-class potential until it rotates beyond the west limb on
21 March.  Activity is expected to be very low to low from 22 March
until the return of Regions 306 and 314 on 01 and 02 April
respectively.  Low level with a chance of moderate activity is
expected after 02 April.

Greater than 10 MeV proton events are possible from Region 314 until
21 March.

The greater than 2 MeV electron flux may reach high levels on 19 – 24
March, 27 – 28 March and again on 04 – 06 April due to returning
coronal holes.

The geomagnetic field is expected to be at quiet to major storm
levels.  On 20 March a CME shock is expected from the X1.5 flare
that occurred on 18 March with major storm levels possible.  The
large equatorial coronal hole is expected to continue to produce
unsettled to isolated minor storm conditions until 21 March.  Two
smaller but more intense coronal holes are due on 25 – 27 March and
30 – 31 March and are expected to produce active to isolated major
storm levels.  A weak but persistent coronal hole is expected on 01
– 04 April with unsettled to isolated active conditions.


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