Subject: SUMMARY: X-ray Event exceeded X1

Space Weather Message Code: SUMX01
Serial Number: 27
Issue Time: 2003 Oct 26 0740 UTC

SUMMARY: X-ray Event exceeded X1
Begin Time: 2003 Oct 26 0557 UTC
Maximum Time: 2003 Oct 26 0654 UTC
End Time: 2003 Oct 26 0733 UTC
X-ray Class: X1.2
Optical Class: 3n
Location: S18E33

LASCO and EIT observed a full halo CME on 2003/10/26.
The event was first observed in C2 at 17:54 UT as a bright
loop front over the W limb; by 18:30 UT the front had
developed into a full halo CME, though faint in the E.
The front first appeared in C3 images at 18:18 UT with
full coverage of the C3 occultor by 20:18 UT. The mean
plane-of-sky speed for this event was 1432 km/s at PA 265,
with possible evidence for modest deceleration.

The CME was probably associated with an X1.2 X-ray flare
observed by EIT between 17:36 - 20:00 UT, centered at
N02W42 with peak emission at 18:36 UT. GOES records this
flare from AR 0484 between 17:21 - 19:21 UT with peak
emission at 18:19 UT. A very large EIT wave, and dimming,
were observed in association with this event. This event
has therefore been determined frontsided.



Oct 27, 2003 Shift Report
--------------------------
Solar activity has been very high since late last week. Several X class flares have ocurred, one
        last Thursday and two yesterday. All had full-halo CME's as well. 
        
        Last Friday SCS 107 was run by command (at ~ 297:13:34 GMT) due to high radiation levels.

        Observations were resumed on Saturday (298:1930) with load OCT2503B.

        Sunday afternoon's pass showed that SCS107 had run autonomously (at about 299:-----. ),
        terminating OCT2503B. 

        Radiation telecon held yesterday afternoon is summarized below:

             Radiation remains too high to resume science. There may be CMEs
             on the way from each of the two X1 flares in the past 24 hours,
             which may arrive on Oct 28.

             Plan A for resuming science is to start after radiation
             exit after the upcoming perigee passage (~300:1200 ) Obsid 5240 (2.8 ks HRC-I)
             for XTE J1810-197 is a TOO which should be included as in that
             orbit, preferably towards the end of the orbit (in case a
             Plan B for later science resumption is needed).

             Momentum must be reduced before science resumes. Momentum will reach
             26 ft-lb-sec at 2003/301/0400 UT (11pm EST Monday night) unless
             corrective action is taken. There is an attitude about 180 degrees
             from the current attitude which will reduce accumulated momentum,
             and FOT MP will build a maneuver-only load (involving a segmented
             maneuver). This maneuver-only load (to be called OCT2603A) will be
             ready by noon tomorrow, and the maneuver will start at 2003/301/0130 UT,
             allowing 2 uplink opportunities for the load at 300/2030 UT and
             301/0025 UT.

        3-day Solar-Geophysical Forecast issued Oct 26 at 22:00 UTC
        Solar Activity Forecast: Solar activity is expected to be high. Regions 484 and 486 are 
        expected to produce C- and M-class flares, and X-class flares are possible.

        Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to active all 
        three days, with possible minor and isolated major storm conditions on days two and three 
        due to partial halo CMEs from both X flares observed today.