IEM Daily Feature
Friday, 17 May 2013

Sioux City's 106

Posted: 17 May 2013 05:51 AM

The featured chart is a timeseries of one minute interval observations from the Sioux City ASOS on Tuesday. The high temperature topped out at 106 degrees after a morning low temperature of 54. The reason it was able to warm so quickly was a very hot layer of air just above the surface that mixed down. The bottom chart clearly illustrates the mixing process as surface wind speeds increased until about noon and then flattened out for the next three hours along with temperatures. This is indicative of having a deep depth of the atmosphere begin mixed, so heated surface air parcels can ascend for a large distance and there is no higher momentum air to mix back down to the surface. Anyway, the noon temperature of 102 degrees was warmest noon temperature the IEM has on record for any site in the state on any date! It was 104 degrees at 1 PM, which was the warmest temperature for that time as well.

Good = 127
Bad = 10

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