GEOALERT SIDC

:Issued: 2024 Apr 26 1250 UTC
:Product: documentation at http://www.sidc.be/products/xut
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# GEOALERT message from the SIDC (RWC-Belgium)                       #
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GEOALERT BRU117
UGEOA 30512 40426 1250/ 9930/ 
12262 22262 38262 
99999
PLAIN
PREDICTIONS FOR 26 Apr 2024  10CM FLUX: 165 / AP: 023
PREDICTIONS FOR 27 Apr 2024  10CM FLUX: 163 / AP: 014
PREDICTIONS FOR 28 Apr 2024  10CM FLUX: 161 / AP: 015

Solar Active Regions and flaring: Solar flaring activity was at moderate
levels over the past 24 hours with only two low M-class flares. There
remain 16 numbered active regions on the visible solar disc. NOAA AR 3645
(beta) is now rotating behind the west limb. NOAA AR 3643 (beta-gamma) and
NOAA AR 3648 (beta-gamma) have decreased their complexity, while NOAA AR
3654 (beta-gamma) has exhibited growth and increased its magnetic
complexity. The strongest activity was an impulsive M1.4 flare, start time
17:03 UTC, end time 17:16 UTC, peak time 17:12 UTC on April 25th produced
by NOAA AR 3638 (beta) from behind the west limb. The solar flaring
activity is expected to be at low to moderate levels over the next days
with likely M-class flaring and decreasing chances for isolated X-class
flaring.

Coronal mass ejections: No Earth-directed coronal mass ejections (CMEs)
have been observed in the available coronagraph imagery over the past 24
hours.

Coronal holes: A positive polarity mid-latitude coronal hole continues to
reside 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 a mild transient arrival. This could be a
glancing blow from the ICME related to the M3.4 flaring produced by NOAA AR
3638 on April 21st. The solar wind velocity was slow varying between 281
km/s and 387 km/s. The interplanetary magnetic field (B) was mildly
enhanced reaching a maximum value of 10.2 nT and a minimum Bz of -9.3 nT.
The B field phi angle was predominantly in the negative sector (directed
towards the Sun). The solar wind conditions are expected to continue to
experience mild enhancements throughout April 26th - April 27th with a
possible further mild glancing blow arrival late on April 27th. Enhanced
solar wind conditions are expected to continue on April 28th - April 29th
with expected mild high speed streams encounters from several positive
polarity coronal holes.

Geomagnetism: The geomagnetic conditions over the past 24 hours were quiet
to unsettled. Predominantly quiet to active conditions are anticipated for
April 26th - April 28th with possible isolated minor storm levels.

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 briefly exceeded the 1000 pfu threshold over the
past 24h and has currently returned back to low values, well below the1000
pfu threshold. The greater than 2 MeV electron flux as measure by GOES 16
and GOES 18 is expected to remain below 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 nominal levels during the upcoming
days.


TODAY'S ESTIMATED ISN  : 137, BASED ON 12 STATIONS.
99999
UGEOI 30512 40426 1250/ 25/// 
1//// 21670 3002/ 4//// 8//// 9//// 
99999

NOTICEABLE EVENTS SUMMARY
DAY BEGIN MAX  END  LOC    XRAY OP  10CM Catania/NOAA RADIO_BURST_TYPES 
25  1311  1321 1327 ////// M1.0          59/3638      V/3III/1 
25  1703  1712 1716 ////// M1.3          59/3638      III/2 
END

UGEOR 30512 40426 1250/ ///// ///// 
99999
USSPS 81202 25013 21522 17002 46329 2/801 31012 44318 31507 24002 43509
2/801 19009 42521 31509 18001 43015 2/801 25004 41813 3/801 20008 37108
3/802 12006 37818 3/801 22030 36713 57521 32003 33221 01203 27002 20520
11302 26019 20511 34508 29009 22426 41404 28004 21506 11303 30000 23412
0/101
USSPS 32404 24052 22522 25002 36717 21302 27004 45528 21503 30002 41914
21402 31007 36608 31406 32008 41622 21509 33022 35513 37517 38004 40115
21303 39004 21714 21506 42008 23826 21505 43013 23007 37517 44007 43317
31408 45003 24412 2/803 46002 32222 31403 47000 12603 0/101
UMAGF 30503 40426 1004/ 25062 1/006 20001 31112
UMAGF 31523 40426 0000/ 25008 1/002 20001 31112
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