Viewing archive of Friday, 15 May 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 May 15 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
15 May 2026	105	024
16 May 2026	102	016
17 May 2026	098	008

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares. The strongest flare was a C5.1 flare (SIDC Flare 7698), peaking at 18:40 UTC on May 14, which was associated with the returning SIDC Sunspot Group 825 (NOAA Active Region 4436, magnetic type beta). There are currently three numbered active regions on the solar disk, all with magnetic type beta. SIDC Sunspot Group 862 (NOAA Active Region 4433) has rotated across the west limb. The solar flaring activity is expected to be low over the next 24 hours, with C-class flares very likely and a chance for M-class flares.

Coronal mass ejections

A Coronal Mass Ejection (SIDC CME 653) was observed in LASCO/C2 and C3 coronagraph imagery on May 15. The CME is related to post-eruptive arcades from SIDC Sunspot Group 825 (NOAA Active Region 4436), observed in SDO/AIA 304 data starting from around 03:00 UTC on May 15. The bulk of the ejecta appears to be directed mainly northward and is not expected to impact Earth. No other Earth-directed CMEs were observed in the available coronagraph imagery.

Solar wind

Over the past 24 hours, the solar wind parameters initially reflected slow solar wind conditions, with an enhancement observed during the last hours of the period due to the arrival of the high-speed stream from the large, negative polarity transequatorial coronal hole (returning SIDC Coronal Hole 147). The solar wind speed increased up to approximately 590 km/s. The interplanetary magnetic field values increased from 4 nT to 13 nT. The Bz component varied between -10 nT and 9 nT. The interplanetary magnetic field angle was mostly in the positive sector until around 20:00 UTC on May 14, when it switched to the negative sector. Mostly enhanced solar wind conditions are expected over the next 24 hours due to the continuous influence of the high-speed stream.

Geomagnetism

Geomagnetic conditions globally were initially at quiet levels (NOAA Kp 1 to 2+ ), becoming unsettled during the last hours of the period (NOAA Kp 3). Locally, geomagnetic conditions were mostly quiet to unsettled (K BEL 1 to 3). Active to minor storm conditions may be possible over the next 24 hours due to the ongoing high-speed stream influence from the large, negative polarity transequatorial coronal hole (returning SIDC Coronal Hole 147).

Proton flux levels

The greater than 10 MeV proton flux was below the 10 pfu threshold level over the past 24 hours. It is expected to remain below the threshold level over the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux measured by GOES 18 and GOES 19 was below the 1000 pfu threshold in the last 24 hours. The greater than 2 MeV electron flux is expected to be below the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence is presently at normal levels and is expected to remain so over the next 24 hours.

Today's estimated international sunspot number (ISN): 048, based on 13 stations.

Solar indices for 14 May 2026

Wolf number Catania	063
10cm solar flux	106
AK Chambon La Forêt	008
AK Wingst	006
Estimated Ap	005
Estimated international sunspot number	052 - Based on 19 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