NOAA SEC Space Weather Bulletin #01-2 — 29 Mar 2001

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

SPACE WEATHER BULLETIN #01- 2
2001 March 29 at 10:07 a.m. MST (2001 March 29 1707 UT)

**** MAJOR SOLAR FLARE ERUPTS, MORE POSSIBLE ****

Space weather increased to strong levels due to a major solar flare
eruption. A category R3 (strong) radio blackout occurred today at 3:15
a.m. MST (2001 March 29 1015 UTC). The blackout was caused by a major
solar flare eruption from a very large, complex sunspot group, referred
to by NOAA space weather forecasters as Region 9393. Category R3 radio
blackouts adversely affect high-frequency radio communications and
low-frequency navigation signals on the sunlit side of Earth. As a
result this morning’s flare, a category S1 (minor) solar radiation storm

began at 9:35 a.m. MST (2001 March 29 1635 UTC). Category S1 solar
radiation storms will adversely affect high frequency radio
communications in the polar regions. Forecasters also expect
geomagnetic storms reaching category G1 (minor) to G2 (moderate) to
occur during March 30 – April 1 as a result of recent Earth-directed
coronal mass ejections. Power systems, spacecraft operations, and
high-frequency radio communications are adversely affected by
geomagnetic storms. In addition, aurora may be visible along the
northern tier of the U.S. this weekend. NOAA forecasters expect that
Region 9393 will produce more major flares before it rotates to the far
side of the Sun on April 5.

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 SEC’s Web site http://sec.noaa.gov or
(303) 497-5127. The NOAA Public Affairs contact is Barbara McGehan
at bmcgehan@boulder.noaa.gov or (303) 497-6288.