RBE

## Community Coordinated Modeling Center Database Of Notifications, Knowledge, Information ( CCMC DONKI ) ## Message Type: Space Weather Notification - Continued Radiation Belt Enhancement ## ## Message Issue Date: 2026-05-22T15:50:17Z ## Message ID: 20260522-AL-002 ## ## Disclaimer: NOAA's Space Weather Prediction Center is the United States Government official source for space weather forecasts. This "Experimental Research Information" consists of preliminary NASA research products and should be interpreted and used accordingly. ## Summary: Significantly elevated energetic electron fluxes in the Earth's outer radiation belt. GOES "greater than 2.0 MeV" integral electron flux remains elevated, recently crossing the threshold of 1000 pfu at 2026-05-22T10:25Z. The elevated energetic electron flux levels observed since 2026-05-16T15:20Z (see notifications 20260516-AL-003, 20260516-AL-004, 20260518-AL-001, and 20260520-AL-001) are caused by the arrival of a coronal hole high speed stream which started on 2026-05-15, reaching maximum sustained speeds of approximately 740 km/s. The solar wind speed observed at L1 is currently around 360 km/s. NASA spacecraft at GEO, MEO and other orbits passing through or in the vicinity of the Earth's outer radiation belt can be impacted. Activity ID: 2026-05-16T15:20:00-RBE-001. ## Notes: This coronal hole high speed stream is also associated with interplanetary shock with ID 2026-05-15T07:14:00-IPS-001 (see notification 20260515-AL-001) and geomagnetic storm with ID 2026-05-15T21:00:00-GST-001 (see notifications 20260516-AL-001, 20260516-AL-002).