What is ‘should-be’?

Ever hear a weather broadcaster use the expression, “our weather should be …”?  For example, it was 48 degrees today, but it “should be” 70.  We (meteorologists) all fall into that trap every once in awhile.

I’ve heard this type of phrasing used repeatedly lately on a local radio station by some of their nationally-based meteorologists.   Rainfall is the latest weather villain in vogue.  We all know we need the rain, but you would think we haven’t had any at all this year when statistics going back to January are quoted.

Our deficit since then is running nearly 9″ below the average.  Sounds pretty bad. But if we go back 6 months, the numbers aren’t nearly as dire sounding, and going back two years things look OK as well.

The point is just that I think we should quit thinking of our weather as “should-be”.  Looking back at statistics is interesting, but can be hugely distorted by choosing the time frame of reference.

Posted by Jim Duncan


4 Responses to What is ‘should-be’?

  1. Sirius...The Star Dog says:

    The ‘should-be’ construction when describing day-to-day weather is a sign of laziness or willful ignorance of the presenter b/c it’s meaningless without context…which is seldom…if ever…offered.

    “Should be’ suggests we are somehow ‘entitled’ to certain weather ‘x’ on any given day just b/c the long-term average happens to be ‘x?’

    Averages are meaningless unless you also include..as context…the spread of values (the standard deviation) around it. Just b/c rainfall YTD is 9″ below average doesn’t mean it’s an outlier.

    Nor is ‘average’ the best measure to describe the most common or likely value b/c of the undue influence exerted by extreme outliers. The median is a far better measure for many meteorological variables… especially annual snowfall. The 30-year average snowfall for RIC is 10.5”. The median over the same period is 20% less. (8.4″).

  2. Mighty Dyckerson says:

    I could not disagree with you less.

  3. What? says:

    Well, if it was 90 in February, I would be saying “it should be cooler out”. In a context like that I think it is absolutely right to ask what the weather “should be”. Even in less extreme examples, such as May or October, I would like to know what the weather “should be” so I know how I “should be” dressing for the day. Long sleeves or shorts? “Should it be” in the 70s or “should it be” in the 30s? These are good things to know.

    Where do you come up with this stuff?

  4. Concernicus says:

    What “should be” the weather today?

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