The K-index, and by extension the Planetary K-index, are used to characterize the magnitude of geomagnetic storms. Kp is an excellent indicator of disturbances in the Earth's magnetic field and is ...

The Station A and K indices show the fluctuations in the magnetic field, tied to specific geographic locations. The indices have a range from 0 to 9 and are directly related to the maximum amount of ...

SWPC has issued a G2 (Moderate) geomagnetic storm Watch for 11 Oct 2026. The Watch covers the expected arrival of two coronal mass ejections (CMEs) that left the Sun on 07 and 08 Oct. The 08 Oct CME ...

An S4 (Severe) solar radiation storm is in progress. NOAA’s GOES-19 satellite measurements show the ongoing solar radiation storm has intensified to Severe (S4) on the NOAA Space Weather Scales, and ...

A Coronal Mass Ejection (CME) arrived at Earth on 10 October. The CME signature was observed in the solar wind beginning at 10/1434 UTC. A sudden impulse of 56 nT was then recorded at the Niemegk, ...

The NOAA/NASA co-chaired, international panel to forecast Solar Cycle 25 released their latest forecast for Solar Cycle 25. The forecast consensus: a peak in July, 2025 (+/- 8 months), with a smoothed ...

A G4 (Severe) geomagnetic storm watch is in effect for the 20 January UTC-day due to Earth-arrival of a coronal mass ejection (CME). The CME blasted from the Sun on 18 Jan, in association with an ...

G4 Levels were first reached at 2:38pm EST (1938 UTC) on 19 January, 2026 upon CME shock arrival. CME passage is expected to continue through the evening with G4 levels remaining possible.

Similar to the bulletins put out by the NWS local forecast offices, SWPC provides Alerts, Watches and Warnings to the public at large about what to expect from Space Weather. These bulletins are ...

On January 23, 2026, NOAA’s Space Weather Follow On – Lagrange 1 (SWFO-L1) observatory executed its final engine burn, successfully entering its final orbital position at Lagrange point 1. Located ...

Solar wind data refers to in situ magnetic field, solar wind plasma, and particle data from any spacecraft located upwind of Earth, typically orbiting the L1 Lagrange point, that is available to SWPC ...