Subject: SOHO/LASCO Partial HALO CME 110307 UCMEO 93001 10307 2130/ 10307 61448 82042 2431/ 117// 333// 40634 10307 61348 81415 12111 11166 1112/ 99999 PLAIN SOHO/LASCO observed a Partial HALO CME on March 07, 2011. Event is first seen in C2 at 14:48 UT as a bright loop centered at PA 40 degrees followed by a deep cavity. The impulsive front expands with extensions PA 243-117 degrees for a total coverage of 234 degrees over the Northern hemisphere. The event continues into the C3 field beginning 15:06 to 20:42 UT out to approximately 24 Rsun. Time/height measurements were marked to 5 points in C2 with speeds of 793.8 Km/sec at position angle 45 degrees. The event is marked to 16 points in C3 where it slightly decelerates. Speeds average through both fields to 634.0 Km/sec at PA 44 degrees. Acceleration -17.41 m/sec^s. SDO/AIA shows a flare of AR 11166 located at [N11, E21] on disk begining 13:48-14:15 UT with a dimming over the North, NE projection and a small wave. NOAA reports a long duration M1.9 Xray flare of AR 11166 beginning at 13:45-14:56 UT. STEREO COR2 B sees the impulsive burst beginning 14:54 UT in it's NW limb as does EUVI 195 shows AR11166 on it's west limb with a flare at 13:55 UT in the beacon data. This is most probably the cause of the HALO event seen in LASCO. The observation of this event is considered 'GOOD'. This CME is determined a FRONTSIDED event. Images and movies and time/height information for this event is available on the web at: http://umbra.nascom.nasa.gov/lasco/observations/halo/110307/ Best regards, Kevin Schenk Solar Heliospheric Observatory EIT and LASCO Operations NASA-Goddard Space Flight Center, USA BT