https://www.swpc.noaa.gov/products/alerts-watches-and-warnings

Space Weather Message Code: WATA99

Serial Number: 8

Issue Time: 2024 Oct 09 1233 UTC

WATCH: Geomagnetic Storm Category G4 or Greater Predicted

Highest Storm Level Predicted by Day:

Oct 10: G4 (Severe) Oct 11: G4 (Severe) Oct 12: G1 (Minor)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at

www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 45 degrees Geomagnetic Latitude. Induced Currents - Possible widespread voltage control problems and some protective systems may mistakenly trip out key assets from the power grid. Induced pipeline currents intensify.

Spacecraft - Systems may experience surface charging; increased drag on low earth orbit satellites, and tracking and orientation problems may occur.

Navigation - Satellite navigation (GPS) degraded or inoperable for hours.

Radio - HF (high frequency) radio propagation sporadic or blacked out.

Aurora - Aurora may be seen as low as Alabama and northern California.

  • happybadger [he/him]
    ·
    2 months ago

    I saw it for the first time during May's storm, which made bright red/purple ones above the Wyoming-Colorado border after 22:00. They're remarkable and if you're within the right latitude range it's worth finding the nearest dark sky area to watch them: https://www.darkskymap.com/nightSkyBrightness

    edit: also me right now-

    Show

  • someone [comrade/them, they/them]
    ·
    2 months ago

    Radio - HF (high frequency) radio propagation sporadic or blacked out.

    Good thing there isn't some other natural disaster happening in, oh, say, Florida that will cause problems with hardline and mobile communications and will require emergency radios to work reliably.

    • Abracadaniel [he/him]
      ·
      2 months ago

      Florida is pretty far below 45degrees latitude so they should be fine.

    • happybadger [he/him]
      ·
      2 months ago

      screm-cool https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=b1da3e76b23f602ef0721201143ad14bc04a01be

      Recently some indications have appeared that several purely meteorological processes in the terrestrial atmosphere are dependent upon magnetosphere variations. To analyse the possible relationship with North Atlantic hurricane intensiÆcation, the authors examine geomagnetic data for ten days prior to all hurricanes over the last 50 years (1950± 1999). A signiÆcant positive correlation between the averaged Kp index of global geomagnetic activity and hurricane intensity as measured by maximum sustained wind speed is identiÆed for baroclinically-initiated hurricanes. Results are consistent with a mechanism whereby ionization processes trigger glaciation at cloud top which leads to hurricane intensiÆcation through upper tropospheric latent heat release.

        • happybadger [he/him]
          ·
          2 months ago

          I wonder what the effect would be if this hit Tuesday-Wednesday instead of Thursday-Friday when the hurricane is waning. It seems like we just dodged a big bullet.