Subj: Fwd: [AstroAlert: A Potential Halloween Night Light Show]
Date: 10/29/00 7:39:55 PM Pacific Standard Time

A s t r o A l e r t
Sun-Earth Alert

Solar Terrestrial Dispatch
http://www.spacew.com

29 October 2000

... as if Halloween night isn't already strange enough...


A moderately energetic solar flare (narrowly escaping a "major" category
event) erupted from active sunspot Region 9209 at 01:54 UTC (9:54 pm EDT) on
29 October. This solar flare was fairly "loud" at many radio frequencies. For
instance, the burst of radio energy at 1800 MHz was almost ten times louder
than the Sun normally is at that wavelength. This flare event was also
associated with a coronal shock wave that propagated through the inner solar
corona at a velocity near 1,200 kilometers per second (roughly 2.7 million
miles per hour), marking the boundary of what is thought to be an outwardly
propagating coronal mass ejection (CME). Although there has not been any
confirming imagery from the SOHO spacecraft regarding the CME, the evidence
is fairly strong that a portion of the associated CME should have been
directed Earthward.

If this holds true, the Earth may see the impact of another coronal mass
ejection disturbance during the mid to late UTC hours of 31 October. This
anticipated disturbance will follow on the heels of the CME that impacted the
Earth near 09:00 UTC on 28 October and produced periods of moderately
vigorous auroral activity for many middle latitude observers across Canada
and the northern United States (see: http://www.spacew.com/www/auroras.html).

This anticipated Halloween aurora display on 31 October has the
potential of being more energetic than the event observed during the last 24
hours, particularly if solar wind conditions within the CME present favorable
properties.

A Middle Latitude Auroral Activity WATCH is being issued for the UTC
days of 31 October and 01 November.

This should be a fairly good opportunity to observe auroral activity
from many middle latitude locations. The moon should not interfere with
attempts to view activity (it sets in the early evening hours as a small
crescent). If the disturbance materializes, periods of active to brief major
auroral storming may grace the skies of many middle and high latitude regions
on Halloween night.


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