>http://www.foxnews.com/story/0,2933,100981,00.html
I don't think that this news story fully explores the current event. The latest
warning/alert forecast for this is as follows:
(From NOAA):
Forecast for next 24 hours:
Space weather for the next 24 hours is expected to be minor.
Geomagnetic storms reaching the G1 level are expected.
Radio blackouts reaching the R1 level are expected.
This takes into account that the IMF is mostly oriented toward the north. When
this is oriented south (Bz is negative), then it will affect the geomagnetic
field. But, if north (Bz is positive), then it will not affect the geomagnetic
field.
When the CME glances the Earth's magnetosphere, the IMF has to be south (Bz
negative), if it were to cause a geomagnetic storm. The thinking at this time
is
that the Bz will not go negative, or if it will, it will not go very far. Thus,
the geomagnetic activity level should not go too high, at most minor storm
level
during the late afternoon and early evening of the 24th (local time).
By the way, the large sunspot is not the cause of geomagnetic storms. The IMF
and solar wind speed, along with enhancements from CMEs, cause geomagnetic
storminess. If the sunspot group throws a flare, however, we might have a short
radio blackout.
The forecast is for minor to moderate flaring.
So, what is in store for the contest (CQ WW SSB) weekend, starting tomorrow?
Solar activity is drastically higher than just a week ago. Now, we have two
very
large sunspot groups. Things look great, in terms of the flux levels expected.
On the other hand, what is in store for the geomagnetic activity and flare
activity? The latest forecast created on 21 October, 2003 shows the following:
2003 Oct 24 165 20 4
2003 Oct 25 165 15 3
2003 Oct 26 165 10 3
2003 Oct 27 165 10 3
Now, from NOAA/SEC, we have this issued on 22 October, 2003:
The geomagnetic field is expected to be at predominantly active levels through
day one of the forecast period. The partial halo CME from today is expected to
arrive mid-day on the 24th of October and may produce periods of major
storming.
Day three should see a return to unsettled to active conditions.
Predictions for flare activity are:
Event Probabilities 23 Oct-25 Oct
Class M 70/70/70
Class X 30/30/30
Proton 15/15/20
PCAF yellow
Expected flux:
Penticton 10.7 cm Flux
Observed 22 Oct 154
Predicted 23 Oct-25 Oct 160/165/170
And, Ap numbers/Geomagnetic conditions:
Geomagnetic A Indices
Observed Afr/Ap 21 Oct 028/039
Estimated Afr/Ap 22 Oct 020/038
Predicted Afr/Ap 23 Oct-25 Oct 020/030-040/045-015/025
Geomagnetic Activity Probabilities 23 Oct-25 Oct
A. Middle Latitudes
Active 40/30/30
Minor storm 25/40/20
Major-severe storm 10/25/05
B. High Latitudes
Active 45/25/40
Minor storm 35/40/25
Major-severe storm 15/30/10
Looking at all of the data, I think that at most we will have active
geomagnetic
activity for most of the contest. Combined with the very high flux, however,
the
conditions for most bands at and below 15 meters should be hopping!
Specifically, I predict that the start of the contest (at 0000Z on 24 October,
2003, which is evening time for most of the USA) will be somewhat rough - polar
paths and paths over high latitudes will be degraded more than mid-latitude
paths. Higher bands will shut down quickly. Low bands should be fair. The full
day of Saturday will fare better. Perhaps, because of the lower Ap and expected
Kp, along with stronger Flux, we'll see great conditions as high as 15 meters.
10 might still show promise. While the geomagnetic field will be active for the
remainder of the period, it will be decreasing. That can make lower bands hot.
So - I would try my luck at it. Think of it - a flux of 150 to possibly as high
as 200. That will open up the higher bands and will also open up many paths
around the world throughout the day and possibly during the night, on 40
through
20. Geomagnetic activity will degrade the strength and duration of the openings
on the highest bands, but not as closed as it could have been if the flux was
at
or slightly below 100, as it has been lately. Again, I think that the combined
high flux and the moderately active geomagnetic field will balance out for good
to possibly excellent conditions depending on the band and time of day, and so
forth.
Of course, it is possible that the sun will surprise us, with massive flares
and
that the Bz will turn sharply and strongly south. If that were to happen,
spend
time with family and friends. :)
73 de Tomas, NW7US (AAR0JA/AAM0EWA)
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