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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Heads up, and tell the banana eaters...
Another flare headed our way...
Event #49 - 28 October 2003
Issued: 16:30 UTC, 28 October 2003
SOURCE EVENT
Class X17.2 Flare in Region 486 at 11:10 UTC on 28 October 2003
Type II: 1250 km/sec
Estimated LASCO-derived Plane of Sky Velocity: 2125 km/sec
ESTIMATED TIME OF ARRIVAL OF SHOCK AT EARTH
Estimated Impact Window: 00:00 UTC on 29 October to 21:00 UTC on 29
October
Preferred Predicted Impact Time: 08:00 UTC, 29 October 2003 (3 am EST on
29 October)
Estimated Shock Strength (0=Weakest, 9=Strongest): 9
Predicted Behavior of IMF at Shock Impact
At Shock Impact, the Interplanetary Magnetic Field is predicted to
initially turn:
SOUTHWARD
IMPORTANT TIME OF ARRIVAL NOTICE FOR NORTH AMERICANS
The preferred time of arrival is ***TONIGHT***, TUESDAY NIGHT (before
you go to bed that night) near or after 3 am Eastern Standard Time).
That's 2 am Central Standard Time on TONIGHT.
That's 1 am Mountain Standard Time on TONIGHT.
That's MIDNIGHT Pacific Standard Time on TONIGHT.
EXPECT RESIDUAL ACTIVITY (LESS INTENSE) TOMMORROW NIGHT (WEDNESDAY, 29
OCT) AS WELL !
EVENT #49 NOTES:
This is the most energetic Earthward-directed event of the solar
cycle.
SEVERE to MAJOR geomagnetic storming is expected to abruptly
commence following the arrival of the shock front from this flare.
This flare was associated with a Ground-Level Event. It was also
associated with very high energy protons at greater than 100 MeV (which
are still climbing, over 5 hours after the event began). A magnetic
crochet was observed over the daylit sections of the ionosphere. An
exceptionally intense shortwave fadeout and polar cap absorption event
are in progress. There are reports this event was observed in
white-light. Intense radio bursts were associated with this event across
the spectrum. The type II shock velocity is not representative of the
observed velocity of this CME. The observed velocity as determined by
SOHO was 2125 km/sec.
This event has the potential to produce the strongest
geomagnetic storm since 1989. Auroral activity could become visible into
the deep low latitude regions. This one is worth driving a good long
distance over to find clear skies. It has better potential to produce
low-latitude aurora than almost any other event observed in the past
decade. Keep in mind that it is also possible the disturbance may not be
nearly as geoeffective as many would like. It all depends on the
character of the magnetic fields imbedded within the coronal mass
ejection. However, we believe it will either be very large, or only
modestly large in terms of its capacity to produce disturbed geomagnetic
and auroral activity. We do not expect this disturbance to be small.
These predictions may be based on preliminary data and may be revised
without warning. The predictions should not be used as a definitive
indication of CME impact times or strengths and may frequently be in
error. The proprietary methods used to estimate shock impact times are
under continual development. Caution is advised.
Attachment:
pgp00039.pgp
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