From Chris St.Cyr (SOHO/LASCO)

The halo event of 1998.01.21, first appeared in C2 at 06:37 UT. Scott Paswaters and I have separately measured a speed of 400 km/sec for the leading edge at PA=180 (South Pole).

From Joe Gurman (SOHO/EIT)

The south polar crown filament, complete with northward "V," erupted shortly after 04:00 UT on Jan 21, 1998. Arcade formation was still on going at 07:00 UT, and a sizable, CME-like darkening appeared at the vertex (SE) of the V at 05:40 - 06:00 UT.

From Dave Speich (SEC/NOAA)

There was no well defined GOES long duration event with this eruption. The post eruption arcade in EIT is quite extensive. To my eye, the CME did appear to propagate slightly above the ecliptic from the far southern launch site. There were no radio bursts reported with this event. The current solar wind velocity is approximately 450 km/s. We are predicting a minor geomagnetic disturbance to begin early on 24 January and continue into 25 January. Maximum Kp values expected are in the 4-5 range.

From Mike Reiner (WIND/WAVES)

I believe that emission in RAD1 from 10-12 UT on Jan. 21 is the type II emissions associated with the halo CME. On the 1/f plot it extrapolates nicely back to ~6 UT at the sun. If I assume fundamental emission and a density of 6 at 1 AU, I get a speed of 476 km/s. Thus I predict it will arrive at Earth ~22 UT on Jan. 24.