* Geomagnetic storm weaker than predicted
* Unlikely to disrupt power grids, GPS - expert
* Some communications problems in polar regions
By Susan Heavey
WASHINGTON, March 8 A solar storm that
shook the Earth's magnetic field on Thursday spared satellite
and power systems as it delivered a glancing blow, although it
could still intensify until early Friday, U.S. space weather
The geomagnetic storm surging from the sun was initially
expected to be strong enough to disrupt power grids, airplane
traffic and space-based satellite navigation systems. But U.S.
government scientists on Thursday downgraded their prediction on
the intensity of the storm - a big cloud of charged particles
spawned by two solar flares.
"At this point, it has been oriented in such a way that the
net effect on the earth's magnetic field has been minimized,"
said Joseph Kunches, a space weather specialist at the U.S.
National Oceanic and Atmospheric Administration (NOAA).
Kunches said there were still some communication disruptions
in the polar regions of the Earth that led airlines to reroute
flights on Wednesday to avoid problems. The storm was not likely
to be strong enough to disrupt GPS systems, he added.
Like hurricanes, solar storms have a rating system, with G1
being less severe and G5 being more intense. Scientists
initially expected a G3 storm, but on Thursday said it turned
out to be a "minor" G1 disturbance.
"Now we're just watching for how this is all going to shake
out," Kunches said, likening the storm to a passing freight
More solar disruptions are still a possibility. The part of
the sun that spawned the flares has been pretty quiet in the
last 24 hours, but that could change, Kunches said.
"Forecasters are still suspicious that (the Sun) could
produce some more eruptive activity," he said.
One thing the storm could still produce is some
spectacular auroras, Kunches said.
In the Northern Hemisphere, the aurora borealis could be
visible at higher latitudes, such as the northern United States,
although the March full moon may make them difficult to see.
(Reporting by Susan Heavey; Editing by Anthony Boadle)