November 12, 2025

A Near "Bomb" Cyclone Approaches the West Coast

 Last weekend, I started getting emails from folks concerned about a "bomb cyclone" approaching Washington state.    Some of the amateur Facebook and YouTube sites were also starting to beat the weather drums.

The reason?  Several model runs at that time had scary forecasts, such as this one for 4 PM Thursday (tomorrow).  The kind of strong low that would easily take out power to hundreds of thousands of local customers.


When I took a look at the situation, I realized the uncertainty of these forecasts was very, very large:  the ensembles of many forecasts have a huge spread in solutions, and the forecasts changed radically run to run.

That is why I did not blog about it.  

We are close enough now to have a good idea of what will occur tomorrow... the rapid development of a strong low off the California coast. 

A low center that will dissipate almost as quickly as it developed.

Here is the pressure analysis for 4 AM this morning.  An amorphous 1002 hPa low-pressure center off of northern California.  Yawn.

Now look at the forecast for 4 AM Thursday morning:  a 986 hPa low has formed.  Impressive.

A deepening of 16 hPa in 24 h.   Not quite the bomb rate (24 hPa in 24 h), but very substantial.


The developing low was quite evident on the visible satellite image this afternoon (see below, and I marked the low-pressure center).

The water vapor satellite imager tonight (8:30 PM) was quite impressive:


By 10 AM on Friday, the low will weaken to 1001 hPa and drift nearly due south.


This storm is predicted to drive some large waves offshore (see wave forecast for 4 PM Thursday), with some getting to 25 feet, and some modest waves reaching the coast.  No big deal.


Here in Washington State, we will get little wind from the low center.  However, it will push a plume of moisture into our region (yes, an atmospheric river) that will provide more welcome rain (see forecast of the water vapor transport below).


The forecast totals through Sunday at 4 AM are impressive in the mountains:



______________________





Enjoy the great outdoors with Play Tennis Seattle. Find tennis partners, tennis coaches, tennis lesson and classes, and join the Seattle tennis community. 


12 comments:

  1. Thank you Cliff for keeping us sane and fighting the fake weather news that those on of the left try to hype up. My wife works for the FCC and recently brought to my attention how the administration, with help from NOAA, are starting to view climate and weather alarmism has an information hazard. Hopefully in a few weeks we’ll see the fruit of their labor with the shut down of these weather forums and Facebook groups.

    This kind of click bait weather nonsense from untrained and unaccredited sources does more harm than good for this country. These charlatans will be bright to justice.

    ReplyDelete
    Replies
    1. Wrong...it is called freedom of expression...it is up to the citizen, to evaluate such things. "Fake WeatherNews"???lollollol.

      Delete
    2. Climate and weather alarmism is an information hazard, and I'm cautiously optimistic that NOAA, the administration, and the FCC can help with this. I will be curious to see how they go about it, and hope that they only target those who are deliberatly spreading lies and misinformation, causing unnecessary and unwarranted fear. The truth must always prevail, especially when lives are at stake, but those who are acting in good faith shouldn't be shut down just because they get a forecast wrong.

      Delete
  2. It's raining in fernfail now. I'm ready for snow

    ReplyDelete
  3. Hey Cliff, I know you have mentioned it before, but can you explain the National Drought Monitor report. As of the 11th they are showing virtually all of Washington still in drought and all of King County in severe drought. Even with a dry summer this makes no sense with current conditions. How do they arrive at the classifications?

    ReplyDelete
  4. At this point, probably safe to say no Thanksgiving skiing.

    ReplyDelete
  5. Wellll . . . the current run of the Euro is making some interesting snow-type noises at the very tippy top of the extended forecast.

    Of course, the next run will feature a hurricane, or a rain of frogs, or a dust storm, or who knows. That Day 14 map has something for everyone . . . eventually.

    ReplyDelete
    Replies
    1. Interesting snow-type noises? As in snow for the mountains, snow for the lowlands, or both?

      Delete
  6. Thanks so much, as always, for explaining the mechanics and the existing predictions. As they said in Jaws, it just may be that "We're going to need a bigger boat". So far, it's a very skookum monsoon season, as it were.

    ReplyDelete

Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

Flooding Ahead

It is now clear that we will have a major precipitation event on Monday and Tuesday, with flooding over vulnerable areas of western Washingt...