SIDC ursigram

:Issued: 2025 Nov 11 1254 UTC
:Product: documentation at http://www.sidc.be/products/tot
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# DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC     #
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SIDC URSIGRAM 51111
SIDC SOLAR BULLETIN 11 Nov 2025, 1254UT
SIDC FORECAST 
SOLAR FLARES  : M-class flares expected (probability >=50%)
GEOMAGNETISM  : Quiet (A<20 and K<4)
SOLAR PROTONS : Proton event in progress (>10 MeV)
PREDICTIONS FOR 11 Nov 2025  10CM FLUX: 180 / AP: 022
PREDICTIONS FOR 12 Nov 2025  10CM FLUX: 180 / AP: 051
PREDICTIONS FOR 13 Nov 2025  10CM FLUX: 180 / AP: 007

Solar Active Regions and flaring: Solar flaring activity was high over the
past 24 hours. Eight numbered sunspot groups were on the disk. The largest
flare was an X5.1 event that peaked at 10:04 UTC on 11 Nov from SIDC
Sunspot Group 687 (NOAA AR 4274) at N23 W23. A Type II radio emission was
observed around 10:40 UTC, which is associated with the X5.1 flare. Two
M-class flares were also produced by this region: an M1.5 at 19:57 UTC on
10 Nov and an M1.4 at 08:09 UTC on 11 Nov. Solar flaring activity is
expected to remain high over the next 24 hours, with M-class flares very
likely and a chance for X-class flares.

Coronal mass ejections: A full halo CME was observed on 10 Nov following
the X1.2 flare (SIDC CME 559) from SIDC Sunspot Group 687 (NOAA AR 4274).
The true radial speed is estimated at about 1300 km/s. The arrival of the
associated interplanetary shock at Earth is expected late on 11 Nov to
early on 12 Nov. A Type II radio emission alert was observed at 10:40 UTC
on 11 Nov. This burst is associated with the X5.1 flare that peaked at
10:04 UTC from SIDC Sunspot Group 687 (NOAA AR 4274). Type II bursts are
typically linked to shock-driven eruptions and often indicate an
accompanying CME, from this an estimated shock speed of 1350 km/s was
given. However, speed estimates from radiospectrography carry
methodological uncertainties and should be treated as preliminary. Further
analysis is ongoing as additional coronagraph imagery becomes available to
refine the true speed and assess any Earth-directed component.

Coronal holes: SIDC Coronal Hole 126, an mid-north coronal hole with
negative polarity, has returned on the disk and is currently situated on
the western side of the Sun.

Solar wind: During the last 24 hours the solar wind speed ranged around 410
to 590 km/s. The total interplanetary magnetic field, Bt ,varied between
about 0.4 and 8.7 nT, while the southward component, Bz, ranged from
roughly -4.6 nT to 6.4 nT. Conditions are expected to become disturbed late
on 11 Nov into 12 Nov with the anticipated arrival of interplanetary
coronal mass ejection (SIDC CME 559) associated with the X1.2 event (SIDC
Flare 6010) that peaked on 10 November at 09:19 UTC, and produced by SIDC
Sunspot Group 687 (NOAA Active Region 4274).

Geomagnetism: Geomagnetic activity was quiet to unsettled overall with
periods of active constions. NOAA Kp reached 4 around 15 to 18 UTC on 10
Nov, otherwise 1 to 3. The Belgian K index similarly peaked near 4 in the
late afternoon and briefly again around 23 to 00 UTC, then eased to 1 to 2
through the morning of 11 Nov. Over the next 24 hours, quiet to unsettled
conditions are most likely, with isolated active periods possible if Bz
turns persistently southward. Additional disturbances remain possible late
on 11 to early 12 Nov with the expected CME arrival. The geomagnetic
response will depend on the magnetic field orientation within the ejecta
and could reach major storm levels (Kp 6 to Kp 7).

Proton flux levels: The greater than 10 MeV GOES proton flux crossed the 10
pfu threshold at 11:30 UTC on 10 November following the X1.2 flare from
SIDC Sunspot Group 687 and has remained at event levels since then. Around
10:00-10:10 UTC on 11 November, coincident with the X5.1 flare from the
same region, the flux increased further. The higher energy channels
responded promptly as well, with clear rises at ?50 MeV, ?100 MeV and a
noticeable rise at ?500 MeV, indicating a hard-spectrum SEP component.
Proton flux is expected to remain elevated over the next 24 hours, with
additional enhancements possible if further major flares occur or as CME-
driven shocks propagate from SIDC Sunspot Group 687 (NOAA Active Region
4274).

Electron fluxes at GEO: The greater than 2 MeV electron flux measured by
GOES 18 and GOES 19 was above the 1000 pfu at the start of the reporting
period. The greater than 2 MeV electron flux is expected to fluctuate
around the 1000 pfu threshold over the next 24 hours. The 24-hour electron
fluence was at moderate levels, it is expected to remain at moderate levels
over the next 24 hours.



TODAY'S ESTIMATED ISN  : 150, BASED ON 07 STATIONS.
99999

SOLAR INDICES FOR 10 Nov 2025
WOLF NUMBER CATANIA    : ///
10CM SOLAR FLUX        : 180
AK CHAMBON LA FORET    : ///
AK WINGST              : 019
ESTIMATED AP           : 014
ESTIMATED ISN          : 157, BASED ON 15 STATIONS.

NOTICEABLE EVENTS SUMMARY
DAY BEGIN MAX  END  LOC    XRAY OP  10CM Catania/NOAA RADIO_BURST_TYPES 
10  1946  1957 2003 N21W20 M1.5 2N       ///4274      VI/2 
11  0802  0809 0813 N21W31 M1.4 SF       ///4274      
11  0949  1004 1017 ////// X5.1          ///4274      II/3VI/3III/2 
END

UMAGF 31523 51111 0000/ 10002 1/019 22212 33535
BT
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