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 2018

Wed Aug 01, 2018
Dry July for Des Moines
01 Aug 2018 05:37 AM
The epic flash flooding to end June has been followed by one of the driest July's on record for Des Moines. The featured chart displays yearly July precipitation totals. 2018's total of just 0.38 inches is the driest since 1975 and the fifth driest on record. The recent dryness has been tempered somewhat by cool overnight lows and lack of excessive daytime heat. This situation looks to change as August progresses and forecasted warmer weather returns to the state.
Voting: Good - 8 Bad - 0

Tags:   jul18  
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Thu Aug 02, 2018
Highs of 90+ in August
02 Aug 2018 05:34 AM
Having the calendar now say August always brings some optimism about the fast approaching fall season, but there is still plenty of time for summer during the month. The featured chart displays the daily frequencies of the high temperature being at or above 90 for Ames during August. The values labelled on the bars are the number of previous years meeting the criterion. While there is some downward slope to this chart, the magnitude is not significant meaning that each day has about the same chance of reaching 90. The forecast currently has a few days approaching 90 during the coming seven days.
Voting: Good - 8 Bad - 0

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Fri Aug 03, 2018
Next Seven Days
03 Aug 2018 05:34 AM
The weekly update to the US Drought Monitor was released on Thursday and showed a continued degradation over southern Iowa. For agricultural crops that are still holding on for some needed rain this growing season, time is running out. The featured map depicts the combination of the most recent Drought Monitor and the seven day forecasted precipitation amount from the Weather Prediction Center. The heaviest totals are inconveniently predicted to the north of the driest area over the state. A silver lining here is that the map is not full of zero precipitation predictions, but hotter temperatures are expected which will increase the stress on already stressed crops in the area.
Voting: Good - 16 Bad - 0

Tags:   wpc   usdm  
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Mon Aug 06, 2018
Latest Date for High
06 Aug 2018 05:36 AM
For areas over southern Iowa that missed out on the rain during Sunday, temperatures were very toasty well into the 90s. Lamoni hit 98 degrees. The featured chart looks at the latest date into a year that a given high temperature was reached. Certainly this warm of weather during early August is not that exceptional. The chart shows the site hitting 98 degrees into the end of September! Highs on Monday are expected to be plenty warm over southern Iowa again.
Voting: Good - 9 Bad - 0

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Tue Aug 07, 2018
Big August Rainfall
07 Aug 2018 05:39 AM
Heavy rains have come to Iowa over the past few days. The featured chart displays MRMS rainfall estimates since Saturday until about 5 AM this Tuesday. The most recent US Drought Monitor is overlain as well. The first round of heavy rainfall completely missed the driest parts of the state, but some rainfall Monday and now on Tuesday has fallen over the driest locations. There was some optimism that more rain would have fallen by now over southern Iowa with this event. Sadly for the area, the near term forecast looks dry. This map will be updated later today once the rain event ends.
Voting: Good - 8 Bad - 1

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Wed Aug 08, 2018
Settings records by year
08 Aug 2018 05:35 AM
Waterloo set a daily record precipitation total on Monday with 1.81 inches reported. This beat the previous record of 1.08 inches set back in 2007. The featured chart looks the number of daily records set each year for the site. The totals shown are counted as time progresses and not the present day totaling of which year holds the current daily records. The black line on the chart is a simple model denoting 365/n, where n is the sequential year number. For example, in 1893 there was no daily records so each day set a record! Then the next year, one would expect to set records on roughly half of the days (365/2). The title on each plot shows the long term average number of records set per year. Interestingly, the values for daily high and precipitation are close together with the low temperature number lagging by about 10%. Will likely look more into this difference in upcoming daily features.
Voting: Good - 8 Bad - 0

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Thu Aug 09, 2018
Mostly on Warm Side
09 Aug 2018 05:33 AM
The featured chart shows a weekly progression of trailing 14 day normalized temperature and precipitation departures for Des Moines. The arrows indicate movement from one week to the next with the labelled day showing when the trailing 14 day departure is valid for. The chart is shown for data this year since the end of April. Please recall how cold and snowy it was in April this year. Since that time and only up until recently, temperature departures have been on the warm side of average and precipitation departures have been both wet and dry. Our current weather is trending toward the dry and hot side of this chart, so our brief period below average on temperatures will end with the next update of this plot.
Voting: Good - 7 Bad - 0

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Fri Aug 10, 2018
Ottumwa Multi-Year Drought
10 Aug 2018 05:34 AM
Based on long term climate sites tracked by the IEM, the driest location in the state over the past two years is Ottumwa (located southeast of Des Moines). The featured chart presents Ottumwa's trailing day precipitation departures over the past two years and the analyzed US Drought Monitor condition for the location. The precipitation departures are plotted for a trailing 91, 365, and 720 day window. The green line shows the accumulated departure over the past two years standing now at 20 inches. The brief stint at D3 classification last year shows up nicely and the rapid improvement with the big rains late last growing season. The same scenario has yet to materialize for the area this year and there is little rain in the forecast for the next seven days.
Voting: Good - 12 Bad - 1

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Mon Aug 13, 2018
August besting July
13 Aug 2018 05:35 AM
For Ames, there is currently about a 50% chance that this August will have a warmer average temperature than the last month of July. The featured chart looks into how common it is for one month to have a warmer average temperature than another for the same calendar year. This situation has happened for 30 years in the past, so it is certainly not a rare occurrence. The current near term forecast continues the warm for August temperatures with highs and lows both slightly above average.
Voting: Good - 7 Bad - 1

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Tue Aug 14, 2018
Days to accumulate Two Inches
14 Aug 2018 05:36 AM
Based on MRMS precipitation estimates, the featured map depicts the number of days one needs to go back in time before accumulating at least two inches of rainfall. This analysis is evaluated for each of the pixels in the gridded product. Two dry areas in the state stick out on this plot, most of southwestern Iowa and parts of far southeastern Iowa. The dark brown areas indicate between 50 and 60 days! The current forecast has some optimism for rainfall over southern Iowa, so hopefully it pans out!
Voting: Good - 12 Bad - 0

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Wed Aug 15, 2018
Play in the Rain
15 Aug 2018 05:36 AM
In the absence of lightning, summer rains can be nice to play in. One of the main reasons this activity is pleasant is that air temperatures are typically warm. The featured chart looks at the frequency of reported air temperatures for Ames by week of the year when precipitation is being reported. A simple weekly average is plotted as well and shows the months of July and August having the warmest temperatures during rainfall. The chart quickly plummets during the fall season, so the chilly rains are not that far away!
Voting: Good - 7 Bad - 2

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Thu Aug 16, 2018
Drought Monitor Weekly Changes
16 Aug 2018 05:36 AM
This week's US Drought Monitor will be released later this Thursday morning and should show continued degradation of the drought situation over Iowa. The featured chart attempts to illustrate the magnitude of the week to week changes in the Drought Monitor depiction over the state. The weekly data is smoothed to give a more visually appeasing appearance. The magnitude of the weekly changes is expressed in units of net one category change in the depiction over an area of the state. Putting those difficult units aside, the relative size shows the larger and smaller changes in the depiction. Of note in the plot is the year 2010, which was a flood year and had no drought analyzed over Iowa. For this year, the changes have been rather muted as the most intense portion of the drought has been confined over far southern Iowa. The lack of recent rains over most of the state now has analyzed drought creeping further north. The chart also nicely shows when the improvements showed up last year, which was late August into October.
Voting: Good - 5 Bad - 0

Tags:   usdm  
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Features for Aug 2018