Thread | Brutkey

Prof. Sam Lawler
@sundogplanets@mastodon.social

I have never seen the word "perihelion" in a weather warning before! Wow.

I'm totally saving this to show my students why basic astro 101 is very practical sometimes (...ok maybe the prairies do not have a tidal flooding problem...but... perihelion!!)

A screenshot of a weather warning for Victoria, BC
COASTAL FLOODING STATEMENT
11:47 AM PST Friday 2 January 2026

Abnormal high tides combined with low pressure may produce minor/moderate coastal flooding.

Elevated water levels accompanied by strong winds and waves are expected, exceeding highest astronomical tides.

What: Risk of coastal flooding due to storm surge coinciding with high tides.
When: This weekend, with the highest risk of coastal flooding on Sunday.

Additional information: The South Coast is entering a period of high astronomical tides as Earth reaches perihelion (Earth's closest point to the Sun). Also, a low pressure system will cross the region this weekend. This falling atmospheric pressure will help further elevate coastal water levels beyond predicted tides, thus increasing the risk of coastal flooding.

Prof. Sam Lawler
@sundogplanets@mastodon.social

RE: https://fosstodon.org/@AkaSci/115828276041483994

Ah, perfect, @AkaSci@fosstodon.org added a diagram and an explanation of why this weather warning is happening!

Happy Perihelion+perigee Moon!

AkaSci 🛰

️
@AkaSci@fosstodon.org

In the northern hemisphere, around midnight, the Wolf Moon will be high in the sky, you know why.
🌝
The moon's perigee and the earth's perihelion on the Sun's side, will result in heightened King Tide.
3/n

My graphic illustrating the elevation of the moon at midnight close to the solstices.

In winter, it is high in the sky in the northern hemisphere, due to the axial tilt of earth.

AkaSci 🛰

️
@AkaSci@fosstodon.org

@sundogplanets@mastodon.social
Curious that they did not mention that the moon is close to perigee around earth, which provides a second contribution to the high tides; the moon's contribution is higher than the effect of perihelion.

Prof. Sam Lawler
@sundogplanets@mastodon.social

And after a few cloudy-but-not-rainy days, we're back to an impressive forecast showcasing Weather Canada's ability to say "rain" in as many different ways as possible

A screenshot of the weather forecast for Victoria BC over the coming days, with a rainy cloud icon on every single day, but slightly different text. Including Rain, Periods of Rain, Showers, and Chance of Showers.

Prof. Sam Lawler
@sundogplanets@mastodon.social

@AkaSci@fosstodon.org If they had managed to work "syzygy" into the flooding statement I might have actually fallen off my chair with excitement! But yes, that is interesting!