:Issued: 2026 Oct 10 1839 UTC :Product: documentation at http://www.sidc.be/products/presto #--------------------------------------------------------------------# # FAST WARNING 'PRESTO' MESSAGE from the SIDC (RWC-Belgium) # #--------------------------------------------------------------------# Major geomagnetic storms have been detected around 18:00 UTC on October 10 with the global NOAA Kp and the local K Belgium indices reaching 7. The geomagnetic storms are caused by an ICME arrival, possibly an early arrival of SIDC CME 727, which lifted off the solar surface on October 08. A strong shock has been detected in the solar wind data (as measured by ACE at L1) at 14:41 UTC on October 10 marking the ICME arrival. The magnitude of the interplanetary magnetic field increased up to 46 nT and the north-south (Bz) component has meanwhile reached almost - 29 nT. Related to the ICME arrival the solar wind speed has peaked at 904 km/s and is currently close to 800 km/s. Further moderate to major storms might be expected in the upcoming hours followed by periods of minor geomagnetic storms. #--------------------------------------------------------------------# # Solar Influences Data analysis Center - RWC Belgium # # Royal Observatory of Belgium # # # # Website http://www.sidc.be. # # E-mail sidc-support@oma.be # # To unsubscribe http://www.sidc.be/registration/unsub.php # # # # Legal notices: # # - Intellectual Property Rights: # # http://www.astro.oma.be/common/internet/en/data-policy-en.pdf # # - Liability Disclaimer: # # http://www.astro.oma.be/common/internet/en/disclaimer-en.pdf # # - Use and processing of your personal information: # # http://www.astro.oma.be/common/internet/en/privacy-policy-en.pdf # #--------------------------------------------------------------------#