Incoming CME, geomagnetic storm may be possible on April 6th

[Ulrich Rieth]

Here is the SIDC message (see below).
Maybe STD will bring another warning soon.
You can also have a look at the ACE EPAM plot @ http://www.swpc.noaa.gov/ace/EPAM_3d.html
It is ramping up nicely, so the CME really seems to be on the way towards earth.
Stay tuned for updated over the easter weekend.
Clear Skies!

 Ulrich


:Issued: 2010 Apr 03 1250 UTC
:Product: documentation at http://www.sidc.be/products/presto
#--------------------------------------------------------------------#
# FAST WARNING 'PRESTO' MESSAGE  from the SIDC (RWC-Belgium)         #
#--------------------------------------------------------------------#
A B7.4 flare peaking at 09:54 UT was detected today in the Catania
sunspot group 56 (NOAA AR 1059) located around S25W05. It was
accompanied by a post-eruption arcade, coronal dimmings, possibly an EIT
wave and a partial halo CME (angular width around 210 degrees). The CME
was first detected at 10:33 UT (by LASCO) and at 09:54 UT (by
SECCHI/COR2 on STEREO A). The CME was moving at a projected
plane-of-the-sky speed of around 250 km/s (according to the LASCO data).
Using some reasonable assumptions on the CME geometry, the true radial
CME speed can be estimated to be around 600 km/s. The arrival of the
corresponding ICME (possibly an interplanetary flux rope) at the Earth
is thus expected in the morning of April 6. The flux rope orientation as
inferred from the SOHO/EIT and SOHO/MDI data is ESW, although it may
change during propagation. STEREO A and B data indicate that the bulk of
the CME was propagating to the south of the ecliptic (according to the
COR2 data). If the flux rope will arrive at the Earth, we expect a
strong geomagnetic disturbance. Currently, the Earth is inside a slow
solar wind flow (460 km/s) with average (5 nT) interplanetary magnetic
field magnitude. Geomagnetic conditions are expected to remain quiet in
the coming hours.
#--------------------------------------------------------------------#
# Solar Influences Data analysis Center - RWC Belgium                #
# Royal Observatory of Belgium                                       #
# Fax : 32 (0) 2 373 0 224                                           #
# Tel.: 32 (0) 2 373 0 491                                           #
#                                                                    #
# For more information, see http://www.sidc.be                       #

[Ulrich Rieth]

The above mentioned CME hit earth early today.
The resulting geomagnetic storm reached a Kp of 7, making it a G3 storm.
Now the solar wind parameters show a subsiding storm, but auroral displays are still possible in high and possibly upper mid latitudes.
Here is the SWPC bulletin.
Clear skies!

 Ulrich

---------------------------------

Official Space Weather Advisory issued by NOAA Space Weather Prediction Center
Boulder, Colorado, USA

SPACE WEATHER ADVISORY BULLETIN #10- 1
2010 April 05 at 12:13 p.m. MST (2010 April 05 1213 UTC)

**** STRONG GEOMAGNETIC STORM IN PROGRESS ****

A geomagnetic storm began at 05:55 AM EST Monday, April 5, 2010.  Space
weather storm levels reached Strong (G3) levels on the Geomagnetic
Storms Space Weather Scale.  The source of the storming is an
Earth-directed Coronal Mass Ejection associated with a weak solar flare
that occurred in Active Region 1059 on April 3 at 05:54 AM EST.  This
is expected to be an isolated storm that should subside quickly.  Other
than the flare and CME erupting on April 3, this active region has not
produced any significant activity.  Systems that can be affected
include electric power systems, spacecraft operations, high-frequency
communications, GPS, and other navigation systems.

Data used to provide space weather services are contributed by NOAA,
USAF, NASA, NSF, USGS, the International Space Environment Services
and other observatories, universities, and institutions. More
information is available at SWPC's Web site http://swpc.noaa.gov

[Ulrich Rieth]

The geomgnetic storm is subsiding.
Short outbusts of activity may still be possible over high latitude regions.
Widespread activity is no longer expected.