SIDC URSIGRAM 31105 SIDC SOLAR BULLETIN 05 Nov 2003, 1220UT SIDC FORECAST (valid from 1230UT, 05 Nov 2003 until 07 Nov 2003) SOLAR FLARES : Active (M-class flares expected, probability >= 50%) GEOMAGNETISM : Major geomagnetic storm expected (A>=50 or K>=6) SOLAR PROTONS : Proton event in progress (>10 MeV) PREDICTIONS FOR 05 Nov 2003 10CM FLUX: 147 / AP: 009 PREDICTIONS FOR 06 Nov 2003 10CM FLUX: 132 / AP: 043 PREDICTIONS FOR 07 Nov 2003 10CM FLUX: 117 / AP: 029 COMMENT: A new extreme flare (X17.4) was again produced by active region Catania#70 (NOAA 0486) yesterday Nov.4 at 19:53UT. Despite its limb location, this event spawned a halo CME, with an initial speed estimated at 2380km/s. Model calculations indicate that the Eastern flank of this disturbance will produce glancing blow to the Earth magnetosphere on Nov. 6. This flare also produced a slowly rising proton event. The GOES proton flux is still rising now: the >10MeV protons reached a maximum of 300 pfu at about 07:00UT and the flux is now decreasing. Geomagnetic conditions are currently quiet to unsettled , as the solar wind speed has now decreased to 500km/s with a stable positive Bz. Therefore, no activity is expected until the arrival of the CME, which can trigger a new major geomagnetic storm on day2. Late on day 3, active conditions are expected as the Earth enters a high-speed solar wind stream from a low latitude coronal hole. Solar activity is expected to drop in the comings days as the large active regions responsible for the repeating X-class flares are rotating behind the West limb. A few M-class flares could still be recorded on day 1. SOLAR INDICES FOR 4 Nov 2003 SUNSPOT INDEX : 067 10CM SOLAR FLUX : 168 AK CHAMBON LA FORET : 044 AK WINGST : 030 ESTIMATED AP : 031 NOTICEABLE EVENTS SUMMARY DAY BEGIN MAX END LOC XRAY OP 10CM TYPE Catania NOAA NOTE 04 1929 1953 2006 S19W83 X17 3B 20000 IV/2,III/3,II/3 70 0486 halo CME 05 0237 0241 0245 S19W89 M1.6 SF 70 0486 END BT