September 25, 2023

Superstorm and Superwaves Offshore

To get big waves, you need strong winds, you need the wind to be around for an extended period, and you want a long fetch over water to allow the waves to develop.

Yesterday and today we have all three due to a nearly stationary superstorm offshore.

First, we have an impressive storm offshore.  Check out the water vapor satellite imagery last night (below), which shows atmospheric water vapor content from space.

Wow... an impressive storm any time of the year, but particularly unusual for mid to late September and unusually far south for late summer.  You can see the plume of water vapor heading into our region from the southwest.  That means rain.


This is an intense low center, with a central pressure last night of around 963 hPa (see sea level pressure map below, with the solid lines being isobars...lines of constant pressure).  That is very low pressure for our neighborhood.  The large pressure differences produce very strong winds.


This is an intense, very slow-moving storm and thus winds have an extended time to work on the water.

That means big waves.

The NOAA WaveWatch3 model predicted big waves offshore last night (9 PM shown), with some offshore waves reaching 25 feet.


During the day today, some of the big waves will reach the Washington and BC coasts, some reaching over 20 ft (see prediction for 4 PM today).    Exciting wave-watching at Westport coming up!

And yes, this is going to be a wet, reservoir-filling week.  The latest National Weather Service National Blend of Models total through Friday afternoon is quite soggy west of the Cascade crest...and even easterly WA gets a piece of it.



10 comments:

  1. Hoping this is a sign of the pattern for winter. Rain influx from the south over running a cold air intrusion over our valley leads to some heavy dumps of snow.

    ReplyDelete
  2. The Langley hill radar has been down for a couple of days any idea when it will be back online?.

    ReplyDelete
  3. Gosh, how will the Seattle Times report the seasonal and natural end of the worst drought in modern history caused by climate change?

    ReplyDelete
    Replies
    1. Simple - they'll just claim that what just occurred is yet another example of how the Climate Doom Loop is still in full effect. Lather, rinse, repeat.

      Delete
  4. Wind speed just east of the low appear to be about 50 mph. That is north of WA's coast. Forecasts for WA (currently) do not go that high.
    Still, 50 mph ought to warrant a name. If Mother Nature knocks the lights out in B.C. and WA we ought to come up with an appropriate name.

    ReplyDelete
    Replies
    1. No we don't. It's just meant to instill fear in the population.

      Delete
  5. Ironically, less precip has fallen at my location in Bellingham for the current month-to-date than had fallen by this date of the month during July.

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  6. Here in southwest BC we've had neither wind nor rain in any significant amounts so far.

    ReplyDelete

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