Viewing archive of Wednesday, 19 July 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Jul 19 1246 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Proton event in progress (>10 MeV)

	10cm flux	Ap
19 Jul 2023	176	019
20 Jul 2023	180	021
21 Jul 2023	180	014

Solar Active Regions and flaring

Solar flaring activity over the past 24 hours remained at moderate levels. Four M-class flares were detected in the last 24 hours produced by active regions NOAA AR 3363 and NOAA AR 3376. The largest was a M2.1-flare, with peak time 20:27 UTC on July 18 produced by NOAA AR 3363 which is rotating off the visible disk. There are currently 8 numbered active regions on the visible disk and an as yet unnumbered active region, which is rotating on disk in the northern hemisphere. NOAA AR 3376 continues to grow and the region produced two M-class flares within a period of 1 hour. In addition to NOAA AR 3376, NOAA AR 3372 and NOAA AR 3373 are the most complex regions on the solar disk but they have only produced C-class flares in the last 24 hours. The remaining active regions were quiet and stable. The solar flaring activity is likely to remain at moderate levels over the coming days with a low chance for isolated X-class flaring.

Coronal mass ejections

The halo coronal mass ejection (CME) from 23:50 UTC on July 17 is expected to impact the Earth with glancing blow on the UTC evening of July 19. A CME was observed in LASCO/C2 coronagraph data from 20:12 UTC on July 18 to the north east with a simultaneous back sided CME to the north west. This first CME to the east was associated, with an M-class flare from NOAA AR 3376 and is being analysed as it may have an earth directed component.

Solar wind

The solar wind speed fluctuated between 460 km/s and 500 km/s. The magnetic field had a peak value of 6 nT. In the last 24 hours the Bz was manly positive with a minimum Bz of -2 nT. The phi angle was negative during the last 24 hours. Enhancements continue to be possible from the expected ICME arrival on the UTC evening of July 19.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet to unsettled (NOAA KP = 3, K-Bel =3). Mostly unsettled to active geomagnetic conditions are expected over the next two days with isolated minor storm periods, due to the predicted CME arrival.

Proton flux levels

The greater than 10 MeV proton flux remained above the 10 pfu threshold in the last 24 hours, although gradually decreasing over the whole period. The proton flux is expected to continue to decrease in the next 24 hours but will remain above the threshold.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux measured by GOES-18 crossed the 1000 pfu alert threshold at 16:10 UTC on July 18 and dipped below threshold values at 00:10 UTC on July 19. The greater than 2 MeV electron flux measured by GOES-16 remained below the threshold. The electron flux is expected to cross the threshold again in the next 24 hours. The 24h electron fluence increased but remains at nominal levels and is expected to be at nominal to moderate levels in the next 24 hours.

Today's estimated international sunspot number (ISN): 160, based on 17 stations.

Solar indices for 18 Jul 2023

Wolf number Catania	148
10cm solar flux	219
AK Chambon La Forêt	014
AK Wingst	018
Estimated Ap	017
Estimated international sunspot number	167 - Based on 24 stations

Noticeable events summary

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

All times in UTC

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