Viewing archive of Thursday, 27 April 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Apr 27 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
27 Apr 2023	136	015
28 Apr 2023	138	008
29 Apr 2023	134	005

Bulletin

Solar flaring activity was moderate during the past 24 hours with an M1 flare detected today at 11:14 UT. NOAA Active Region (AR) 3288 (magnetic configuration Beta, Catania group 67) produced the brightest event and most of the C-class flare activity. The recently-named NOAA Active Region (AR) 3289 (magnetic configuration Beta, Catania group 69) produced three C-class flares with the brightest being a C3 today at 00:59 UT. More M-class flare activity is likely in the next 24 hours, mainly from NOAA AR 2388.

No Earth-directed Coronal Mass Ejections (CME) were observed in the last 24 hours. Two partial halos CME launched yesterday at 07:00 UT and today at 00:48 UT, automatically detected by CACTUS are judged to not be geo- effective.

The greater than 10 MeV proton flux was at nominal levels over the past 24 hours and is expected to remain so for the next 24 hours. The greater than 2 MeV electron flux was above the 1000 pfu threshold between yesterday 12:16-19:55 UT and today 02:45-03:30 UT and below the limit for the rest of the past 24 hours. The 24-hour electron fluence increased to moderate levels since yesterday 15:20 UT. In the next 24 hours hours the greater than 2 MeV electron flux is expected to increase above the 1000 pfu threshold again and the 24-hour electron fluence to remain at moderate levels.

The Solar Wind (SW) conditions are affected by a High Speed Stream (HSS) that arrived at yesterday 17:30 UT, earlier than anticipated. The SW speed increased from about 550 km/s to 700 km/s. The total magnetic field (Bt) increased from 5 nT to 10 nT at the arrival of the HSS and features a very gradual drop since. Its North-South (Bz) component fluctuated between -9 and 9 nT during the last 24 hours. The interplanetary magnetic field phi angle was almost exclusively directed towards the Sun over the last 24 hours. The SW conditions are expected to remain in the fast wind regime for the next 24 hours.

Geomagnetic conditions were globally active (Kp 4+) today between 00:00-06:00 and moderate to quiet (Kp 4- to 3) for the rest of the past 24 hours. Locally the conditions were moderate (K BEL 3) throughout the last 24 hours. Geomagnetic conditions are expected to become moderate to quiet in the next 24 hours.

Today's estimated international sunspot number (ISN): 123, based on 15 stations.

Solar indices for 26 Apr 2023

Wolf number Catania	077
10cm solar flux	137
AK Chambon La Forêt	026
AK Wingst	016
Estimated Ap	021
Estimated international sunspot number	097 - Based on 23 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page