SIDC ursigram

:Issued: 2024 Apr 25 1247 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 40425
SIDC SOLAR BULLETIN 25 Apr 2024, 1247UT
SIDC FORECAST 
SOLAR FLARES  : M-class flares expected (probability >=50%)
GEOMAGNETISM  : Active conditions expected (A>=20 or K=4)
SOLAR PROTONS : Warning condition (activity levels expected to increase,
but no numeric forecast given)
PREDICTIONS FOR 25 Apr 2024  10CM FLUX: 204 / AP: 007
PREDICTIONS FOR 26 Apr 2024  10CM FLUX: 204 / AP: 013
PREDICTIONS FOR 27 Apr 2024  10CM FLUX: 204 / AP: 011

Solar Active Regions and flaring: Solar flaring activity remained at high
levels in the past 24 hours with multiple low M-class flares. There are 16
numbered and several unnumbered active regions on the visible solar disc.
NOAA AR 3645 (beta-gamma) remains the largest region, while NOAA AR 3643
(beta-gamma-delta) and NOAA AR 3648 (beta-gamma-delta) became the most
complex ones. NOAA AR 3639 (beta), NOAA AR 3646 (beta) and NOAA AR 3647
(beta) have decreased the complexity of their underlying magnetic field.
The strongest activity was M2.0 flare, start time 22:54 UTC, end time 23:05
UTC, peak time 22:59 UTC on April 24th produced by NOAA AR 3637 (beta) from
the west limb. The remaining M-class flaring was produced by NOAA AR 3645
and NOAA AR 3648. The solar flaring activity is expected to be at moderate
to high levels over the next days with likely further M-class flaring and
25% chance for isolated X-class flaring.

Coronal mass ejections: No Earth-directed coronal mass ejections (CMEs)
have been observed in coronagraph imagery over the past 24 hours. Type II
and type IV radio bursts were reported related to C9.4-class flaring from
NOAA AR 3638 14:10 UTC on April 24th. The resulting westward CME is
estimated to have no impact on Earth.

Coronal holes: A positive polarity mid-latitude coronal hole is currently
residing on the central meridian in the southern hemisphere. The high speed
stream emanating from it might arrive to Earth on April 28th, possibly
superimposed with expected preceding high speed stream arrival.

Solar wind: Over the past 24 hours the solar wind parameters (ACE and
DSCOVR) were indicative of background slow solar wind regime. The solar
wind velocity was predominantly below 400 km/s. The interplanetary magnetic
field (B) was weak with a maximum value of 4.8 nT and a minimum Bz of -3.9
nT. The B field phi angle was alternating between the negative and the
positive sector (directed towards and away from the Sun). The solar wind
conditions might experience mild enhancements on April 25th - April 28th
with possible mild high speed streams encounters related to several
positive polarity coronal holes.

Geomagnetism: The geomagnetic conditions over the past 24 hours were quiet.
Quiet to active conditions are anticipated for April 25th with chances for
isolated minor storm levels on April26th -April 28th.

Proton flux levels: Over the past 24 hours the greater than 10 MeV GOES
proton flux was at background levels and is expected to continue so over
the next days, pending any fast eruptive solar activity.


Electron fluxes at GEO: The greater than 2 MeV electron flux as measure by
GOES 16 and GOES 18 has exceeded the1000 pfu threshold over the past 24h
and is expected to repeatedly exceed the 1000 pfu threshold in the upcoming
days. The 24h electron fluence was at boundary of nominal to moderate level
and is expected to be at moderate levels for the upcoming days.


TODAY'S ESTIMATED ISN  : 220, BASED ON 11 STATIONS.
99999

SOLAR INDICES FOR 24 Apr 2024
WOLF NUMBER CATANIA    : ///
10CM SOLAR FLUX        : 199
AK CHAMBON LA FORET    : 004
AK WINGST              : 002
ESTIMATED AP           : 142
ESTIMATED ISN          : 261, BASED ON 20 STATIONS.

NOTICEABLE EVENTS SUMMARY
DAY BEGIN MAX  END  LOC    XRAY OP  10CM Catania/NOAA RADIO_BURST_TYPES 
24  1207  1214 1239 ////// M1.4          60/3645      
24  2227  2250 2254 ////// M1.1          73/3657      III/1VI/1 
24  2254  2259 2305 ////// M2.0          59/3638      
25  0140  0149 0201 ////// M1.0          60/3645      
END

UMAGF 30503 40425 1004/ 24067 1/004 21110 30000
BT
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