Viewing archive of Thursday, 19 October 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Oct 19 1233 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
19 Oct 2023	135	017
20 Oct 2023	133	019
21 Oct 2023	131	013

Solar Active Regions and flaring

The solar flaring activity was at low levels. Catania sunspot regions 12 and 4 (NOAA AR 3465 and NOAA AR 3464) showed signs of decay and were quiet. Catania sunspot group 9 (NOAA AR 3468) was quiet and stable. The solar flaring activity is expected to be at low levels over the next 24 hours with C-class flares likely and a low chance for isolated M-class flares.

Coronal mass ejections

A faint Coronal Mass Ejection directed to the south-east, visible in SOHO/LASCO-C2 data from 06:15 UTC October 18, was associated with an eruption to the south west of NOAA 3468. The bulk of this CME is directed to the south but a glancing blow may be possible at Earth from late on October 21. A CME detected in SOHO/LASCO-C2 from 01:30 UTC October 19, directed to the north-west, is associated with an eruption from beyond the west limb and is not expected to be Earth directed.

Coronal holes

A small, negative polarity coronal hole in the northern hemisphere has begun to transit the central meridian on October 19.

Solar wind

The solar wind parameters reflected the ongoing influence of the high-speed stream. The interplanetary magnetic field had a peak of 13 nT around 12:00 UTC October 18, before gradually decreasing to values around 6nT. Bz had a minimum value of -11 nT. The solar wind speed ranged between 400km/s and 480 km/s. The interplanetary magnetic field orientation was predominantly in the positive sector (field directed away from Sun). The solar wind speed is expected to remain slightly enhanced over the next day under the influence of the weak high-speed stream and possible new high-speed stream associated with the small negative polarity coronal hole which crossed the central meridian on October 16. Additional further enhancements in the speed and magnetic field may be possible on October 20 and October 21, due to the glancing blows predicted for the CMEs from October 16, 17 and 18.

Geomagnetism

During last 24 hours the geomagnetic conditions were at unsettled to active levels (NOAA KP between 2 and 4- and K Bel 2-4). Geomagnetic conditions are expected to be at unsettled to active levels on October 19. Active intervals are also possible on October 20 and 21, due to the predicted CME glancing blows.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux was at nominal levels and is expected to remain so over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux remained below the 1000 pfu threshold as measured by GOES 16. It is expected to remain below this threshold over the next days. The 24 hour electron fluence was at nominal levels. The electron fluence is expected to be at nominal levels for the next days.

Today's estimated international sunspot number (ISN): 052, based on 11 stations.

Solar indices for 18 Oct 2023

Wolf number Catania	///
10cm solar flux	135
AK Chambon La Forêt	025
AK Wingst	011
Estimated Ap	012
Estimated international sunspot number	065 - Based on 16 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

All times in UTC

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