From Chris St. Cyr, LASCO

An (almost complete) halo appeared in C2 at 1998.01.02 23:28 UT. It first appeared in the NW at that time, but it spread to almost completely surround the occulting disk. A preliminary speed measurement yields 500 km/s for the leading portion in the NW. This event was followed by an extremely bright structured (prominence), also appearing in the NW at 09:42 this morning (1998.01.03) in C2.

From Joe Gurman, EIT

The large, dynamic filament system on the NW limb finally erupted this morning after two weeks of teasing. The EIT CME watch movie shows arcade formation in AR 8126 just S and E of the prominence as early as 01:14 UT. The prominence rises relatively slowly for several hours thereafter until a dramatic eruption between 09:00 and 09:20 UT. There was also arcade formation starting at 09:37 UT in the area where the prominence footpoints had been. An absorption landscape turned into emission.

From David Speich, SEC Duty Forecaster

We expect the disturbance from the nearly complete halo to begin during the latter half of 06 Jan and continue through 07 Jan. The level of disturbance is not expected to be severe (max K-index of 4-5 during that period).

This event(s) is complex. I believe there were two distinctly different events. A seven hour long GOES x-ray event and the halo CME correlated well in time with a SOON observation of a disappearing filament near N44W15. This filament was along the neutral line running down to region 8126 and I was not surprised to hear of the EIT observation of arcade formation near region 8126. No YOHKOH data are available to verify the total areal coverage of the arcade. The "second" event seemed to be related to the large polar crown filaments near the west limb. These filaments were along a totally different neutral line and quite distant from the first disappearing filament. Obviously, there is widespread re-organization of the northern polar fields.