IEM Daily Feature
Tuesday, 16 May 2017

Decreasing Variability

Posted: 16 May 2017 05:34 AM

The featured chart displays three metrics assessing the daily high temperatures for Ames. The top panel shows the daily high temperature standard deviation and the other line shows the day to day variability in high temperature. The bottom panel shows the ratio between these two metrics. The annual cycle is most noticeable with both variances decreasing into the summer season. The daily climatology variance is shown to be higher than the day to day variance. This is sort of a back handed way to show that the day to day change in our weather is less variable than overall climatology for a given day. Rewording, our high temperature tomorrow is more likely to be close to today's than for the date last year. The downward trend into the summer season is the impact of increased humidity, which acts to dampen the magnitude of the daily temperature swings.

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