Past IEM Features tagged: hot
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.
Yesterday was a remarkably warm day with high temperatures in the mid to upper 90s with some automated stations reporting 100 degrees! It has been a long time since Iowa has seen this warm of weather. The featured chart displays the year of the previous date that had temperatures as warm as those reported by the automated sensors. The plus symbol means the previous date was during this year. For some locations, this was the warmest temperature in over 10 years! For the IEM computed statewide average, yesterday was the warmest day since 1 August 2006 and the warmest day in June since 1988.