WOXX16 KWNP 111141
ALTK09

Space Weather Message Code: ALTK09
Serial Number: 8
Issue Time: 2024 May 11 1139 UTC

ALERT: Geomagnetic K-index of 9o
Synoptic Period: 0900-1200 UTC
Active Warning: Yes
NOAA Scale: G5 - Extreme
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact primarily poleward of 40 degrees Geomagnetic Latitude.
Induced Currents - Widespread voltage control problems and protective system problems may occur; some power grid systems may experience component failures or protective device trips resulting in blackouts or disruption of service. Pipeline currents can reach hundreds of amps.
Spacecraft - Systems may experience anomalies to include: extensive surface charging, unexpected orientation and attitude changes, uplink/downlink errors, and satellite orbit degradation.
Navigation - Satellite navigation (GPS) may be degraded or unavailable for days.
Radio - HF (high frequency) radio propagation may be impossible in many areas for one to two days.
Aurora - Aurora may be seen as low as Florida to southern Texas and southern California.

# Issued by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Recent messages, data, and help at http://swpc.noaa.gov/alerts/
# Send questions to SWPC.Webmaster@noaa.gov