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 Oct 2017

Mon Oct 02, 2017
Warmest Months
02 Oct 2017 05:33 AM
October is starting off to a warm start with above average highs expected for the immediate future. The featured chart looks at the warmest months on record for average high temperature for Ames. The October record shown is 75.5 degrees back in 1963. So it seems to be a high bar to reach if we wanted to best that mark this year!
Voting: Good - 5 Bad - 0

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Tue Oct 03, 2017
Sept 2017 Precip Ranks
03 Oct 2017 05:29 AM
The featured map presents IEM estimated September 2017 precipitation ranks by climate district. A stripe of very dry conditions are analyzed from Missouri up into Michigan and Ohio. Iowa was just on the western edge with very dry conditions over eastern Iowa and wetter over western Iowa. Some significant amounts of rain are forecasted to fall over Iowa during the next seven days, which will further delay the corn harvest in the state.
Voting: Good - 9 Bad - 0

Tags:   sep17  
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Wed Oct 04, 2017
Fall Season Precipitation
04 Oct 2017 05:25 AM
The featured chart displays fall season (September thru November) total precipitation for Ames. The past three years have seen above long term average precip for the period and this year's seasonal total appears to be on its way with ongoing rain now and still just under two months of time left. A long term trend line is fitted to the data and would indicate little trend with these totals.
Voting: Good - 6 Bad - 0

Tags:   fall  
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Thu Oct 05, 2017
Upcoming Wet Three Days
05 Oct 2017 05:33 AM
The featured map displays Weather Prediction Center forecast 72 hour precipitation totals between 7 PM last night and 7 PM Saturday evening. Most of southwestern Iowa is shown in the 3 to 4.5 inch range with most of Iowa even above two inches. This may be the most widespread and largest rainfall event in the state so far this year. Of course, a bit of pessimism rules after recent rain events have managed to not fully cover the drought stricken areas over southern Iowa. This event will likely set back the fall corn and soybean harvest progress as it would take a bit of time for fields to dry out from this much rain.
Voting: Good - 12 Bad - 0

Tags:   wpc  
Fri Oct 06, 2017
Ames vs Des Moines
06 Oct 2017 12:40 AM
For the climate locations tracked by the IEM for Ames and Des Moines, the precipitation total for Ames has been higher than Des Moines for the third straight year (so far). The featured chart presents the yearly difference in precipitation between the two. Blue bars are years whereby Ames had a larger total. Interesting that prior to this recent stretch, 9 of the past 10 years to that had higher totals for Des Moines. It will be interesting to see how both sites fair with the ongoing heavy rainfall expected today and Saturday.
Voting: Good - 10 Bad - 0

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Mon Oct 09, 2017
Waffling Front
09 Oct 2017 05:36 AM
A frontal boundary was draped over Iowa Friday evening and into Saturday. The featured chart displays a time series of air temperature and wind direction reports from a weather station located on the Agronomy Hall building at ISU. It is interesting to notice how the front was waffling back and forth over the area for the evening. The sign of this movement can be seen by the change in wind direction and air temperature. The switch of the wind to the northwest brought cooler temperatures and the swing back to southeast brought warmer temperatures.
Voting: Good - 7 Bad - 0

Tags:   front  
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Tue Oct 10, 2017
Hour of New Minimum
10 Oct 2017 05:34 AM
Some of the coldest air of the season arrived over Iowa overnight. A number of locations will likely set new fall minimum temperatures. The featured chart looks at the hour at which and the new minimum fall temperature that was reported during October for Des Moines. Of interest are the very few number of reports between noon and 6 PM. This shows that it is very difficult to set new fall minimum lows during the afternoon hours as it is difficult to get very cold air into the region when even minimal amounts of sunshine can provide some heating. It will be interesting to see if this situation can happen today with very cool temperature expected this afternoon for places like Des Moines.
Voting: Good - 7 Bad - 0

Tags:   oct  
Wed Oct 11, 2017
Can be plenty colder during October
11 Oct 2017 05:35 AM
Tuesday was a bitter taste of late fall with cold winds and rain. For Mason City, the high did not get out of the lower 40s. The featured chart displays minimum daily high temperatures by month for the site. The coldest value shown for October is a mere 20 degrees back in 1925. These are the coldest high temperatures, so 20 was the high for the day! So it can get plenty colder than what we experienced on Tuesday in Iowa.
Voting: Good - 7 Bad - 0

Tags:   monthly  
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Thu Oct 12, 2017
Clear Skies Make a Difference
12 Oct 2017 05:36 AM
The coldest temperatures of the season were experienced Wednesday morning over areas that had clear skies overnight. Other locations in the state with clouds were many degrees warmer. The featured chart displays the combined time series of all airport weather stations in the state. When the site was reporting clear sky conditions the dot is blue and for all other sky conditions the dot is grey. A remarkable and pretty contrast is shown by the chart with the coldest areas being clear and warming quickly with the rising sun during the morning hours. The impact of clouds during the daytime can be seen as well to suppress heating by reflecting the sun's energy prior to it arriving at the Earth's surface.
Voting: Good - 89 Bad - 1

Tags:   clouds  
Fri Oct 13, 2017
Wetter than Ames
13 Oct 2017 05:36 AM
The featured map displays the frequency of the long term climate site having a year to date precipitation total larger than Ames. Sites plotted in blue have a higher total this year. It is interesting that most of the blue sites are in areas that are typically below Ames. However, those percentages are not too far from 50% so this year isn't too far out of the ordinary. Ames has been on the gradient this year of the drier conditions over south and southeastern Iowa and the recent wet period for western Iowa. The forecasted heaviest rain over the next few days is expected over this dry area.
Voting: Good - 7 Bad - 0
Mon Oct 16, 2017
First Sub-32 Time Series
16 Oct 2017 06:01 AM
Temperatures are quite chilly this morning but failed to breach 32 degrees for places like Ames. The featured chart displays the temperature time series for the first sub-32 fall temperature each of the past years since 1996. The current time series for 2017 is shown and was comparable to previous years, but did not quite make it! Temperatures are expected to warm this week, so Ames's next chance of freezing weather is a few days away yet.
Voting: Good - 10 Bad - 1
Tue Oct 17, 2017
Fall Season Minimums
17 Oct 2017 04:05 AM
Low temperatures Monday morning were some of the coldest we have seen so far this season, but a widespread freeze has yet to happen. The featured map displays the coldest temperature so far from the weather stations located at the state's airports. Values well below freezing have been confined to far NW Iowa. The current forecast keeps us well above freezing into at least early next week.
Voting: Good - 5 Bad - 0
Wed Oct 18, 2017
Hourly Temps above 70
18 Oct 2017 05:03 AM
Temperatures warmed nicely on Tuesday into the lower 70s. For mid October, that is doing rather well. The featured chart presents a frequency heat map of having the hourly temperature at or above 70 degrees. For mid October, the afternoon frequencies are around 30%, so these warm of temperatures happen about one out of three days. More 70s are in the forecast this week before a chance of rain and cooler temperatures arrive for the weekend.
Voting: Good - 11 Bad - 0

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Thu Oct 19, 2017
Day to Day High Change
19 Oct 2017 05:35 AM
Temperatures warmed a bit more on Wednesday with highs well into the 70s for much of the state. For the day to day change in high temperature, having a warmer temperature has been the most common this month as shown by the featured chart. The chart shows the overall monthly averages and those for 2017 for the day to day change in high temperature for Des Moines. A number of months this year have seen more than average number of days with the high temperature warmer than the previous day.
Voting: Good - 7 Bad - 0

Tags:   highs  
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Fri Oct 20, 2017
Freezing Temps Coverage
20 Oct 2017 05:34 AM
Freezing temperatures have been difficult to come by so far this fall season. The featured chart looks at the areal coverage percentage of fall freezing temperatures. The percentages represent the amount of area that has seen at least one day with sub freezing temperatures. The blue line is the average coverage based on data back to 1893. The largest and smallest coverage are shown as well along with the accumulation for this year and last. This analysis puts this year at 25%, which would be average for the end of September. It is interesting to see this year mimic 2016 with the late start to sub freezing temps.
Voting: Good - 10 Bad - 1

Tags:   freeze  
Mon Oct 23, 2017
Wet October
23 Oct 2017 05:34 AM
Rains have been plentiful for much of the state this October. The featured map shows estimated precipitation departures from long term average based on NOAA MRMS estimates and gridded NWS COOP data. This analysis places the entire state above average for the month to date period. The dark blues would indicate regions with over four inches of surplus rain this month. Needless to say that all this rain has slowed the crop harvest progress in the state.
Voting: Good - 9 Bad - 0

Tags:   oct17  
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Tue Oct 24, 2017
October Daily Winds
24 Oct 2017 05:35 AM
Winds were a bit blustery on Monday with the NWS issuing a Wind Advisory for portions of the state. The featured chart displays daily averaged wind speed and direction for Sioux City this month. Monday's average came in as the windiest day so far this month for the site. Windy conditions are typical this time of year as the battle of the air masses helps to drive strong pressure gradients and subsequently winds. More windy days are expected for much of the rest of this week.
Voting: Good - 12 Bad - 1

Tags:   oct17  
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Wed Oct 25, 2017
More Cold Air
25 Oct 2017 05:36 AM
For most of the Continental US, this fall season has been rather warm. Cooler temperatures did finally break through for much of the central and eastern US on Tuesday. The featured chart presents the percentage of NWS climate sites that had above or below average high temperatures for each day since early September. Please note that no spatial weighting is done with this analysis, so it isn't a strict areal coverage. It is interesting to see how the warmer than average highs have dominated this season with only yesterday showing something closer to 50/50 split since early September.
Voting: Good - 5 Bad - 1

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Thu Oct 26, 2017
El Nino and Winter Weather
26 Oct 2017 05:32 AM
NOAA recently released their winter season forecast. For Iowa, the forecast called for about average temperatures and slightly above normal precipitation. One of the many tools used to make this forecast is the current and forecasted El Nino index. The La Nina conditions have taken a bit longer than expected to develop and the index currently still has a ways to go before getting to La Nina state. Anyway, the featured plot combines the El Nino index along with three month averaged temperatures and precipitation. The two right hand side plots provide the direct comparison and a simple linear fit. Of course, there is no magic bullet here with strong correlations to predict the upcoming winter season. The weather forecast though is more definite over the near term with chances of snow arriving for the weekend!
Voting: Good - 6 Bad - 2

Tags:   elnino  
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Fri Oct 27, 2017
The Gamut of Products
27 Oct 2017 05:35 AM
Our first taste of winter arrived in force overnight with very chilly temperatures and even some snow! Of course, the fall season in Iowa can experience summer-like to winter-like weather. The featured chart presents NWS Des Moines issued headlines since the first of September. While there have not been all that many headlines issued, they do run the gamut of products issued by the NWS. The plot shows Severe Thunderstorm Warning, Dense Fog Advisory, Wind Advisory, Flash Flood Warning, Frost Advisory, and now even a Winter Weather Advisory.
Voting: Good - 8 Bad - 0

Tags:   warnings  
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Mon Oct 30, 2017
GDD Maturity Struggle
30 Oct 2017 06:41 AM
The corn harvest in Iowa this year has been a bit behind schedule due in part to wet conditions and a late maturing crop. Thankfully, an early freeze did not happen, so crops were able to eventually reach maturity. The featured chart looks at the period between accumulating 2200 to 2500 Growing Degree Days (GDD) based on the given planting date for a location in northeastern Iowa. These chosen GDDs levels represent maturity of commonly grown corn. Corn that was planted late into May really struggled to reach maturity with the slow GDD accumulation this year.
Voting: Good - 7 Bad - 0

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Tue Oct 31, 2017
Cold Halloween High
31 Oct 2017 07:09 AM
High temperatures today are expected to struggle today to reach even the low 40s. This would be rather cold for Halloween as shown by the featured chart. It depicts the high temperature for Des Moines for each previous 31 October. The average high is much warmer than what we will experience today. Only a few years have seen colder highs than today.
Voting: Good - 4 Bad - 1

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Features for Oct 2017