September 28, 2021

Gulf of Alaska Storm Season Begins

Some of the most ferocious storms of the planet develop in our backyard:  the Gulf of Alaska.

Storms that are not hurricanes or typhoons but capable of producing winds and waves comparable to Category 3 tropical storms.

And one will occur in a few days.

The satellite imagery of these storms is remarkable, as illustrated by a powerful example from September 26, 2012.  Masses of frontal clouds swirl into the low center, not unlike water circling into a drain.  The low center is in the center of the swirl.  

The energy source of these powerful storms comes from contrasting cold and warm air, with warm southerly flow in front of the storm and cold air circling behind.  The popcorn-like, modeled cloud field south and west of the low center in the above picture indicates cold, unstable air.  This storm had plenty of fuel

The central sea-level pressure in Gulf of Alaska low centers can drop as low as 930 hPa (hectopascals, also known as millibars).   Such pressures are similar to the central pressures of major hurricanes. The strongest storms to hit the Northwest rarely get down even to 980 hPa.   

And then there are the winds.   Gulf of Alaska storms can possess gusts to 80 mph or more and sustained winds reaching 50-70 mph.   Associated ocean waves that have exceeded 100 ft.

Autumn is actually a favored time for Gulf of Alaska storms, something illustrated in these figures from a climatological study (Mesquita et al. 2010).  This figure shows the relative number of storm tracks, for each season.  The lower right is fall.  Gulf of Alaska watch out!

This Week

A very energetic Gulf of Alaska storm will form later this week.    The latest National Weather Service GFS model run, valid 11 PM Friday, shows an impressive 947 hPa low center, just south of Alaska with sustained winds reaching 64 knots.   Just achieving category 1 hurricane strength (sustained winds of 64 knots or more).

The European Center model is also going for a big storm, but a bit weaker and further to the east.

This is a rapidly intensifying storm (it was 992 hPa only 24 h before) and thus is called an atmospheric BOMB.  Atmospheric bombs must deepen by at least 24 hPa in 24 h.  This one doubles that.  Impressive.  Very impressive.

Last Chance to Take My 101 Class as an ACCESS STUDENT

As I noted in previous blogs (see repeat below), I am teaching atmospheric sciences 101-- the introductory class in weather and climate-- this fall. Class starts tomorrow!

If you are over 60 and a Washington State resident you can take it as an ACCESS student for very little cost (normal fare would be around $1800).  You can attend the class in person or over zoom.

ACCESS students don't officially get registered until 3 days into the quarter, so if you are going to register, send me an email and I will send you the zoom link so you won't miss the first class.  Classes will be recorded.

Atmospheric Sciences 101

Like last year, I am teaching atmospheric sciences 101:  a general introduction to weather and climate, this fall.  You can learn more about the class on the class website.  I talk about everything from the basics of the atmosphere to weather prediction, thunderstorms, hurricanes, and local weather to global warming and climate.

I will be teaching the class in person at the UW, but will also make it available over zoom.  Thus, folks can take it remotely.

If you are over 60, you can take the class through the ACCESS program for a very nominal charge (something like $15).   Last year I had over 125 folks do so.

So if you are a UW student looking to learn about weather or a non-student interested in the topic, I welcome you to join me this fall.  My first class is on September 29th.


  1. Countdown to the media declaring that this is the direct result of, two, three...

  2. Thank you for making weather knowledge available in so many ways for us — and for keeping it digestible for non-scientific leaning brains.

  3. Not going to lie...I get goosebumps when this time of year arrives (for precisely the reasons/excitement Cliff describes above). Now if we can just nudge some of these, say, 700 miles further south...

    1. The Columbus Day Storm of 1962 (that I witnessed as a teenager) had a lowest pressure reading of 956....I cannot even imagine what a storm with a 930 reading would be like, I hope such storms stay in the Gulf of Alaska!

  4. Thanks for the continuing education- much appreciated.

  5. Atmos 101, great class! I took it with Professor Richard Reed back in 1984 I believe. He loved discussing weather forecasts and we always spent the first 15 minutes of each lecture going over the daily forecast, satellite photos and radiosonde readings.

  6. Cliff, go to and look at this home page. Climate change turned southwest drought from bad to worse. In it says the dry climate might be natural variability but what made it worse was higher temperatures caused by human caused global warming...would like to here your thoughts. Both scientifically and personally. The personally is as to why this group of "scientists" pushes false narratives. Just the money and grants?

    1. Budd... it all depends on what you mean by drought. If ones is talking about precipitation....the report notes that there is no trend towards drought. But if you include temperature--the warming produces more evaporation...which is what they are talking about. This is not a peer reviewed scientific paper by the way..cliff

    2. We are coming out of a quarter century flood cycle accentuated by 52 year and 26 year solar cycles... then the 13 year cycles.... the Sun revolves around the Earth.... that is what the Climate Change Activists would have us believe... it’s everywhere now. Don’t understand how or why the intelligentsia would drink the Kool-Aid en masse... i’m old enough to remember Jones/Guyana... it seems like everything is now “blown up” into crisis mode; lack of investigation/ knowledge/history has lead us into this constant PTSD cycle of doom... it’s the Earth, the Sun, and the Moon.... doing what they do Mostly... yes WE have an impact; Yes, the Earth will out survive us... the amount of energy/impact created by higher class CME’s has more impact on our “climate” than our blink of humanoid civilization could ever produce. Why Modern Meteorology fails to take the greatest driver of climate and short and long term “patterns” ; ie The SUN; in its hindcasts/nowcasts/forecasts is beyond my belief.

    3. Remember the total eclipse 2 or 3 years ago? We live on the Evil East Side, north of the band of totality. I looked at everything, and almost didn't go to the totality zone because we would be >90%. At the last minute, I said, "Oh, why not?" and we drove into the zone.

      If you want a brief but powerful demonstration of the sun's power over all of us, nothing is more vivid for the layman than the 15-degree temperature drop that occurs in totality zone. I am very far from some sort of woo-woo mystic shaman, but more people should experience it.

      The Seattle eco types (in their green-painted Subarus) don't have a clue, and they don't want to. Reality is too scary.

  7. Cliff, could you provide a discussion/review of the new "Unsettled" climate science book by Steven Koonin, if you've read it?

    I found it very illuminating. It provides good context for some of your critiques of the media and climate activists, but I'm curious what you think as a scientist.

  8. Hi Cliff,

    I am in the process of getting registered for ATM S 101 as an ACCESS program student. You suggested I email you while I await the completion of the registration process, but I can't seem to find your email address in the blog. Would you please share that with me?

    Jeffrey Coleman

  9. The past quarter when you had Access students, there was grumbling that you wouldn’t take their questions and they were excluded from some of the material. Has this been fixed for next quarter?

    1. John... UW rules are clear....ACCESS students are auditors and can't take time in class. I do plan to add some extra sessions for ACCESS students to ask questions..cliff


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