November 24, 2013

The Chanukah-Thanksgiving Weather Miracle

The last time it occurred was 1888 and the next occurrence won't be for 77,000 years:  The first day of Chanukah and Thanksgiving will occur on the same day, called Thanksgivukkah by some.

What do you think are the implications of combining "The Festival of Lights" with the day of gratitude for the blessings provided to our nation by a higher power (to paraprhase George Washington's proclamation of November 26, 1789)?    The answer should be clear to anyone that is meteorologically inclined:   a day with a great deal of sunshine over the entire nation.  A day with a lack of storminess and ill-weather.  And here in the favored Pacific Northwest we should be particularly blessed, because we deserve it.

Let me begin with the national outlook for Thanksgiving Day.  Below is the GFS model forecast
by the National Weather Service that is valid at 4 PM Thursday PST (7 PM Thursday EST).   This forecast shows three-hour precipitation (shading) and sea level pressure.

The signs of divine intervention (or at least Thanksgivukkah intervention) are obvious.

Precipitation is supernaturally avoiding virtually the ENTIRE US.   Where there is precipitation over the ocean, it sudden ends at the coasts.  The only exception is far NW Washington State, but  not many folks live there and most of those watch Canadian TV.  In other words, they don't count.
But there is more.   Look at the sea level pressure pattern (solid lines).  High pressure dominates most of the nation and there are no low pressure centers or storms influencing the U.S. mainland.  Even most of Alaska is experiencing high pressure.  As a trained meteorologist let me assure you that to see the entire U.S. spared of inclement weather in late November is a miracle of the first order.

Living in God's country here in the Northwest, we can, of course, expect a special benediction by this confluence of Chanukah and Thanksgiving.   Plus, we suffer from bad weather more than most and are thus more deserving of special intervention.   Monday, November 25th, will be the 6th straight day without rain, during a period when the climatological chance of rain is around 65%!   And the chances looks certain that Puget Sound will go without measurable rain at least through Wednesday (8 days), with some light rain late on Thanksgiving.  

Does the number eight (8) ring any bells with you?  It should.   The miracle of Chanukah was that there was enough oil in the temple for one day, but it lasted a full eight days.  Here is Seattle we will enjoy eight dry days, when we would have been lucky to have had one.   Profound and bit scary.

So how unusual is such a string of 8 dry days at Seattle Tacoma Airport?  I can answer that.

Here is a plot of the probability of getting at least .01 inch over a period of eight days at Seattle Tacoma Airport.  The probability is very high, around 97%.  So the probability of getting less than than .01 inch over 8 days is only 3%.  Very unusual to say the least.

Not convinced yet?  Have you been reading about the new comet, called Ison, that appeared in our night skies?  Guess what day it will be closest to the sun and thus brightest--potentially very bright?  Thanksgivukkah.

I have spent my life as a scientist, following the laws of logic and physics to describe and forecast atmospheric phenomena.  But I, steeped in science and technology, must acknowledge that there are occurrences beyond the ken of human knowledge that represents the intervention of a divine power greater than our facilities.  This is such a time.  Happy Thanksgivukkah.


  1. they don't count! That's not very Christian Cliff.. :) Shalom and Happy Thanksgiving

  2. Dear Cliff:

    True, I live in far NW Washington (San Juan Islands). And true, I watch Canadian TV as my sole source of broadcast TV. But I have a weather station, have actually conversed with you in Friday Harbor, and have left comments on this blog. Shouldn't that mean I count and should be entitled to divine intervention?

  3. Congratulations Cliff, you've outdone yourself today. I am happily among those who "do not count". Life here in the No Account Zone is especially quiet and peaceful, though it does tend to rain more than it ought to.

    In the spirit of Thanksgiving, you are forgiven!

  4. Delightful post, Dr. Mass -- thanks! And just to be clear, it looks like it's just the FIRST DAY (which of course follows the first night) of Chanukkah, an 8-day festival, that will not again fall on Thanksgiving Day according to our current calendars for many thousands of years; not that Chanukkah won't fall during Thanksgiving Day at all until then (

  5. Looks like we may be looking at some cold temps/snow next week. Could you let us know your opinion on what the models are looking like? Not sure if this is just a tease as usual since it's so far out.

  6. Isn't that the probability of having rainfall in any 8-day period? Not the probability of having 8-straight days of rainfall?

    I mean, you're correct, but the premise wasn't. :-)

  7. Got to love a blog post that results in these 4 Ad Choices:

    ► Weather

    ► Miracle Healing

    ► Chanukah

    ► Storm Forecast

  8. Thanks again for not taking yourself too serious. This why I think you would make a great Mayor!

  9. Agreed Deen....Cliffs probability statement is not correct as written.

    Ironic given his views on math education... :)

    Love the blog entry anyway though

  10. Like gshall, I live in far NW WA (Bellingham), have left comments on the blog, and had, until quite recently, a weather station which was active on wunderground! I'm dismayed to learn that I do not count.

  11. We will enjoy this rare event and get things ready for ... winter!
    So Cliff, how is it the weather looking say next Sunday? You are extremely smart to get a bit closer before commenting but I am glued to the model runs. It looks like a nowcast opportunity (which I think is the best idea in weather forecasting). I'll look for a post in a few days when the weather gets into the high res runs and simply closer. Some people may need to be aware of adverse weather possibilities at end of Turkey weekend travel.

  12. Yes, Cliff...I, too, am looking forward to your take on the weather for next week. The NWS and Scott Systek are really talking about it, but are reminding us that it's still nearly a week away so the model runs could change their mind. I'm looking forward to what you have to say about it as you usually keep us well informed without all the hype....

  13. Reading today's Mt. Rainier Recreational Forecast it uses the phrase, "at the surface", such as "freezing level at the surface". What is meant by "at the surface"? Do they mean sea level or what?


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