Past IEM Features tagged: dry

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Extreme Dryness

13 Dec 2023 05:30 AM
Those of you that monitor RADAR every day probably noticed the reflectivity returns work into southwestern Iowa late Tuesday afternoon and evening. These returns were not producing much at the ground level as extremely dry air was present between the falling water aloft and ground. The Omaha sounding launched Tuesday evening captured an astounding -46.7 Celsius dew point temperature at 925 hPa. For those of you hoping for English units, the dew point was -52 Fahrenheit at about 1500 feet above the ground. The featured chart presents how the Tuesday evening sounding for dew point temperature compared with the period of record archive for the site at the various mandatory observation levels. For the 925 hPa level, this was just shy of the coldest/driest value observed on record. A manual computation found this profile to be the second driest behind that -50.5C value on 29 Feb 2010 at 0 UTC. Such extremely dry air masses typically originate from stratosphere and are brought to the near surface via energetic storm systems.

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Good: 14
Bad: 0

Tags:   sounding   dry  

20 straight dry days

20 Oct 2015 05:36 AM
It is not your imagination, it has been very dry this October! For Des Moines, the last reported precipitation was 20 days ago back on 29 September. The featured chart displays the longest dry periods for Des Moines for each day of the year. The longest streak shown by the chart is 29 days back in 1952. This analysis counts trace reports as precipitation events. There is a chance of rain today and then again to end the week.

Voting:
Good: 14
Bad: 11
Abstain: 7

Tags:   dry   precip