Past Features

This page lists out the IEM Daily Features for a month at a time. Features have been posted on most days since February 2002. List all feature titles.

Features for Aug 2022

Mon Aug 01, 2022
50 days to get Two Inches
01 Aug 2022 05:30 AM
The dryness this summer continues to be of great concern and with hotter temperatures this week, the impacts will quickly grow. The featured map presents the number of days one needs to travel back in time before accumulating at least two inches of rainfall based on NOAA MRMS precipitation estimates. Southern Iowa is certainly of worst off on this map with the brown splotches representing at least 50 days to accumulate those two inches. There are at least chances of rainfall in the forecast, but nothing looks too widespread and the heaviest totals will mostly stay off to Iowa's east.
Voting: Good - 15 Bad - 0

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Tue Aug 02, 2022
Year of Last 100
02 Aug 2022 05:28 AM
While previous forecasts were more bullish on portions of Iowa seeing 100+ degree highs this week, the current forecast over the next two days has slightly "cooler" temperatures forecast. The trade off is that the humidity will be on the dramatic increase with heat index values above 100 degrees instead. So it is a good time to dust off the map showing year of last 100+ degree high temperature for the NWS long term / COOP sites tracked by the IEM. The map shows some micro-climate effects as some sites have not seen 100 degrees for over 20 years while others have had much more recent occurrences. Humidity levels play a roll in this map as local increases in humidity change the energy budget and effectiveness of daytime heating in warming the lower atmosphere.
Voting: Good - 13 Bad - 0

Tags:   100  
Wed Aug 03, 2022
Peak Dew Point
03 Aug 2022 05:31 AM
It was ugly hot in Iowa on Tuesday with heat index values well above 100 degrees thanks to air temperatures well into the 90s and dew points in the 70s. The month of August is still squarely within the summer months for Iowa, so such weather is not a surprise. The featured chart looks into the date of the year for Des Moines with the highest dew point temperature. The value for 2022 was set at 77 degrees back on 13 June, so that was not quite exceeded Tuesday evening. The bottom left panel shows a fare amount of spread for when the peak dew point temperature occurs, but it is generally found during the peak crop transpiration time in July and early August.
Voting: Good - 9 Bad - 0

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Thu Aug 04, 2022
August Hourly Records
04 Aug 2022 05:30 AM
While not an official weather metric that the National Weather Service tracks, the IEM maintains a database of hourly airport weather observations. The featured chart shows the warmest hourly observations from the Des Moines airport during the month of August. The extremely warm and muggy overnight on Wednesday set a new August record of 83 degrees at 7 AM and tied at the same value at 8 AM. Such hot and steamy conditions overnight are very dangerous as un-airconditioned buildings and livestock will struggle to cool off to recover from the day time heat. Conditions will be cooler on Thursday with over night temperatures back to comfortable levels, which again helps to make things a bit more bearable.
Voting: Good - 9 Bad - 0

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Fri Aug 05, 2022
Summer Season Precipitation
05 Aug 2022 05:30 AM
Precipitation has been difficult to come by for much of Iowa this summer. The just released US Drought Monitor update had significant deterioration, specifically over southern Iowa. Summer in Iowa tends to either feast of famine for precipitation as both extremes tend to increase their respective extremity with dry conditions limiting moisture and thus storms, with the opposite situation having the opposite effect of more storms increasing moisture and increasing future storm chances. An illustration of this feast of famine can be found with the featured chart plotting summer season (Jun-Aug) precipitation for Ames. This year continues the past three years being below average. The long term linear fit trend is upward, but the fit is not statistically strong and being pulled upward by the wet years of 1993 and 2010.
Voting: Good - 12 Bad - 0

Tags:   summer  
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Mon Aug 08, 2022
Sioux Falls Record Rainfall
08 Aug 2022 05:35 AM
'Tis the season for extremely heavy precipitation events. The atmosphere is loaded with moisture and overnight storms are fed by expansive reservoirs of humid and unstable air by the low level jet. Storms do not move very fast thanks to limited winds aloft and tend to back build / train over top the same locations producing prodigious amounts of rainfall. You may recall the record rainfall event two weeks ago for St Louis. On Sunday, it was Sioux Falls turn with 5.44 inches reported for the day. The featured chart presents the maximum daily totals by month for the site. Yesterday's event bested the previous high of 4.59 by a comfortable margin. Iowa has seen its share of localized and heavy rainfall events over the past few days. The rainfall is certainly welcome and likely able to help the corn and certainly help the soybeans that are both at critical stages for yield potential.
Voting: Good - 9 Bad - 0

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Tue Aug 09, 2022
Southern Iowa Drought
09 Aug 2022 05:30 AM
While NW Iowa has seen the most persistent drought this year, the situation over southern Iowa is rapidly deteriorating. This week's update to the US Drought Monitor considers rainfall or lack thereof up until Tuesday morning. The featured chart presents NOAA MRMS estimated departures from average over the past week. It is rather amazing to see the alignment between this product and the most recent drought monitor analysis. Only some portions of far north central Iowa saw significant rainfalls over areas analyzed in drought status. Much of the past week featured scorching heat, which further increases the impact of little rainfall.
Voting: Good - 11 Bad - 2

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Wed Aug 10, 2022
Sioux City Struggles
10 Aug 2022 05:30 AM
Precipitation has been a struggle this summer over much of Iowa. For parts of NW Iowa, the struggle has been real for the entire calendar year as shown by the featured chart of year to date accumulated precipitation. The red line is this year's accumulation and is shown at the bottom of the range of values for the date. Rewording, the year to date accumulation this year is the lowest on record for the site at just over nine inches. The wettest and driest full year is plotted as well along with the present NCEI climatology. It is too bad that all that rain that fell just north over Sioux Falls on Sunday could not have been shared a bit further south.
Voting: Good - 8 Bad - 0

Tags:   2022  
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Features for Aug 2022