SPACE WEATHER ADVISORY BULLETIN #06- 4
2006 December 13 at 8:02 a.m. MST (2006 December 13 1502 UTC)

**** ACTIVE SUNSPOT GROUP PRODUCES SIGNIFICANT FLARE ****

NOAA sunspot Region 930 produced a category R3 (Strong) radio blackout with an associated S2 (Moderate) solar radiation storm at 0240 UTC, 13 December (9:40 P.M. EST, 12 December). The SOHO/LASCO instrument also observed a powerful and fast Earth directed coronal mass ejection with this activity. As a result of this activity, a significant geomagnetic storm is expected to impact the Earth approximately 1800 UTC, 14 December (1:00 P.M. EST). NOAA sunspot Region 930 yielded a strong R3 radio blackout and a strong S3 solar radiation storm on 05 December.

This region has been unproductive over the past five days. The active region is now a large sunspot cluster which is still rotating across the visible disk. Because of the current position of Region 930, further activity has greater potential to promptly impact Earth.
Agencies impacted by space weather storms should continue to closely monitor space weather conditions during the next five days.

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