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 Feb 2024

Thu Feb 01, 2024
Drought Monitor Updates
01 Feb 2024 08:27 AM
The weekly update to the US Drought Monitor was just released and much of the analyzed drought over the country was improved, including Iowa. The featured chart presents a time series cartoon of weekly US Drought Monitor classification changes for the contiguous US. The blue areas represent net improvements and red areas degradation. The height represents the amount of area changed by one classification with the unit height being the size of the contiguous US. It is interesting to denote the winter time improvements happening this year that are repeating what happened during the winter last year. For Iowa, January saw significant amounts of precipitation over much of the state and it indeed has helped the drought situation. We still could use more precipitation before the start of the growing season and parts of northern Iowa have been missing out on big events this winter.
Voting: Good - 9 Bad - 1

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Fri Feb 02, 2024
Waterloo's 9 Degree Beat
02 Feb 2024 05:30 AM
Temperatures again warmed nicely on Thursday with a number of locations setting record high temperatures, including Waterloo at 57 degrees, a full nine degrees warmer than the previous record of 48 set back in 1931! The featured chart presents the dates and the amount the new record beat the previous record for high and low temperature for Waterloo. The low temperature beats are presented as negative numbers for the purposes of chart readability. One does not need to go back very far to find a more extreme beat of high temperature for the site on 15 December 2021 at 20 degrees! The near term forecast continues to look rather warm for the first week of February.
Voting: Good - 16 Bad - 0

Tags:   record  
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Mon Feb 05, 2024
13 Dense Fog Advisories
05 Feb 2024 05:43 AM
This year has seen the NWS issue many Dense Fog Advisories with far western Iowa under one this Monday morning. The featured map presents the number of such advisories issued per county so far this year. Carroll and Crawford county lead this tally with 13. The lack of cold and dry continental air masses from areas to our north is one of the reasons why we continue to see so much fog as air temperatures are easily able to cool off to the dew point supported by elevated humidity levels. The near term forecast has even warmer temperatures and lows forecast above freezing, which seems to be supportive of more fog!
Voting: Good - 11 Bad - 1

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Tue Feb 06, 2024
Limited Cover of Snow
06 Feb 2024 05:30 AM
The featured chart presents a daily time series of IEM estimated areal coverage of at least one inch of snow over Iowa this season. There is just one period of significance to be found with all that mid January snow cover now melted away by the first week of February. There is still plenty of time for the state to once again be engulfed by snow, but as we get closer to spring, the snow covered periods become more fleeting thanks to ever lengthening days and increasing solar energy. The short term forecast continues our recent stretch of record to near record highs, but there is some hint that a return to colder weather will be possible by the middle of next week.
Voting: Good - 12 Bad - 0

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Wed Feb 07, 2024

Snow Comes & Goes
07 Feb 2024 05:30 AM
Today's featured movie presents National Snow and Ice Data Center SNODAS analyses since the first of the year. The daily analysis of snow depth nicely shows the rapid onset of snow cover over Iowa during January and the rapid removal into February. With the snow all gone and a lack of cold air masses from our north, temperatures have been running very warm for this time of year with records being set somewhere in the upper Midwest about every day. Even warmer temperatures are expected into Thursday along with a chance of thunderstorms.
Voting: Good - 16 Bad - 0

Tags:   snodas  
Thu Feb 08, 2024
Marginal Risk
08 Feb 2024 05:39 AM
The Storm Prediction Center presently has a day 1 Marginal Risk of severe convective weather for far eastern Iowa, southern Wisconsin, and northern Illinois. This categorical risk threshold was added back in 2015 as something slightly lower than their "slight" threshold. Today's marginal risk area just barely clips the NWS La Crosse County Warning Area (CWA) and the featured chart presents the period each year between the first and last marginal risk. The red tick bars represent individual dates with a marginal risk. With a limited period of record, only last year had an earlier date of 16 January. While severe weather seems very unlikely for Iowa, very warm temperatures for the second week of February are very likely with highs in the lower 60s for some!
Voting: Good - 12 Bad - 1

Tags:   spc  
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Fri Feb 09, 2024
Record Start to February
09 Feb 2024 05:30 AM
Thursday was yet another very warm day this February with record high temperatures set at a number of locations, including Waterloo besting their previous record by nine degrees with a high of 64. This may feel like déjà vu as an IEM Daily feature last week discussed Waterloo besting a record then by nine degrees as well! Severe thunderstorms were able to fire late in the day over far southeastern Iowa and even produced a few tornadoes in Illinois and Wisconsin. Thursday continued what has been a very warm February. The featured map presents IEM estimated average temperature ranks by climate district for this month ending Thursday morning. A sea of ones is shown indicating the warmest period on record since at least 1893. Temperatures will not be as warm on Friday, but still very mild for this time of year.
Voting: Good - 16 Bad - 0

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Mon Feb 12, 2024
ERA5-Land Soil Moisture
12 Feb 2024 05:30 AM
The IEM website attempts to curate datasets useful to support sponsored research and make those products readily available. Today's featured chart highlights a recently added dataset and how it tells a very interesting story leading into this growing season. Some backstory first, the recent years have seen a proliferation of high spatial and temporal resolution "reanalysis" datasets that contain many variables that are difficult to find long term observation archives of. One of the most popular reanalyses is known as ECMWF Reanalysis v5 (ERA5) and recently a down-scaled variant called ERA5-Land was released with hourly data back to 1950! The IEM has processed a few of the variables made available from ERA5-Land and done grid point samples to combined these with the long-term daily climate sites over the contiguous US. The featured chart presents the 0 to 1 meter depth volumetric soil moisture for a grid cell including Ames. The tan area represents the range of daily values since 1950, with the green area showing the width of one standard deviation, the red line being the simple average, and black line the 2024 values. There is a 5 day delay for ERA5-Land data availability, but the 2024 value nicely shows how much water the model says made it from our recent rainfall and snow melt events. This analysis indicates our current soil moisture state near average. This website will be building out more tools and options that include this dataset, so your feedback is certainly welcome!
Voting: Good - 13 Bad - 1

Tags:   era5land  
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Tue Feb 13, 2024
Accumulated Snowfall Departures
13 Feb 2024 05:30 AM
The featured map presents NWS season snowfall departures (in inches) for their primary climate tracking sites. Negative values indicate a below average accumulation of snowfall. Much of the Midwestern US is shown below average with the largest departures found over Minnesota into Michigan. Some of these same areas had near record snowfall just last year. There is still certainly plenty of time this cold season to see snowfall events and we'll even see a chance of accumulating snowfall later this week.
Voting: Good - 13 Bad - 0

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Wed Feb 14, 2024
Red Streak
14 Feb 2024 05:30 AM
In honor of Valentine's Day, today's Daily Feature presents a chart showing a streak of red days! In this case, each of those red days representing a positive departure from average for the daily high temperature for Des Moines. The chart also nicely illustrates the story of this year's weather with one very cold stretch of days in January and the rest above average! Remarkably, only one day this February has been below 10 degrees above average. Wednesday will continue the streak above average, but a return to something closer to average arrives on Thursday. So enjoy the warmth outside and hopefully warmth from your family/friends today.
Voting: Good - 14 Bad - 0

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Thu Feb 15, 2024
Comparing with 2023
15 Feb 2024 05:30 AM
The featured plot is an attempt to visually compare daily high and low temperatures for this year and last for Ames. The plot also contains the daily climatological range between the record low and high temperature along with the range between the daily average low and high. The overlay of the two years visually helps identify periods that had similar and dissimilar temperature periods. For 2024, only that brief period during mid-January can you find days spent below the average low temperature. This is a new plot type on the IEM, so as always, your feedback is welcome.
Voting: Good - 11 Bad - 3

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Fri Feb 16, 2024
'23-'24 Winter Storm #10
16 Feb 2024 05:30 AM
A quick moving winter storm clipped extreme northern Iowa on Wednesday night into Thursday morning. The largest reports were found in Dickinson County of just over three inches. The main band of snow fell just north of the state with Minneapolis setting a daily record of just under seven inches on Wednesday. The next snow producing storm is already here this Friday morning and will be out of the state by afternoon. The forecast then quickly returns us to the mild weather that has dominated much of February.
Voting: Good - 14 Bad - 31

Tags:   winter2324  
Sat Feb 17, 2024
'23-'24 Winter Storm #11
17 Feb 2024 11:59 AM
The second of two fast moving snow producing winter storms dropped a few inches of snow over Iowa Thursday night into Friday morning. The featured map presents an analysis of available NWS and CoCoRaHS reports. The largest totals approaching four inches were found over the Des Moines metro area. The snow from this event and the one from the day previous will not last long as a return to mild February temperatures begins on Sunday.
Voting: Good - 16 Bad - 0

Tags:   winter2324  
Mon Feb 19, 2024
Snowfall Local Storm Reports
19 Feb 2024 02:38 PM
The National Weather Service issues a product named "Local Storm Reports" (LSR), which contain public and other sourced reports of significant weather observations. The IEM maintains an archive of these, which are available for download in either a processed form or raw text products (i.e. LSRDMX). This product is commonly used by NWS offices to disseminate snowfall reports, which can then be plotted within the IEM LSR App and analyzed within Autoplot 207, among other tooling available on this website. The featured chart presents a monthly accounting of the number of LSRs issued by the NWS for Iowa with type of "SNOW". The seasonality of this LSR type is obvious and the lack of snowfall events so far this February is clear when compared with recent years on record.
Voting: Good - 8 Bad - 0

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Tue Feb 20, 2024
Monthly Frequency of 50+
20 Feb 2024 05:30 AM
After a brief bout of winter-like temperatures and a bit of snow last week, we are firmly back in late March / early April weather with Monday seeing high temperatures soar into the 50s for nearly all of the state. The featured chart looks into the monthly frequencies of having a daily high temperature of at least 50 degrees for Ames. The tan bars show the rank percentile of a 50 degree temperature for that month and the blue bars present the yearly average number of days for that month. The x-axis labels show the most recent month with the given number of days at a minimum or maximum value. For the months of July and August, all days on record have been above 50. For the months of December through March, there have been years unable to get even one day at or above 50!
Voting: Good - 9 Bad - 0

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Wed Feb 21, 2024
Besting February 1954
21 Feb 2024 05:30 AM
For many of the long term climate sites in Iowa, February 1954 was the warmest February on record for average temperature. This year appears to be taking a run at the record with yet another very warm day in Iowa on Tuesday. The featured chart presents a scenario plot of month to date average temperature for Waterloo. The black line shows the record value for 1954. The red line is the 2024 to date value with each tan line representing a scenario consisting of a previous year's Feb 21-28(or 29) values appended onto this year's values. The scenarios show a 12% chance of beating 1954 based on what has happened in the past. The actual forecast through the end of the month looks very warm and it seems likely that 2024 will come in as warmest February for Waterloo.
Voting: Good - 11 Bad - 0

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Thu Feb 22, 2024
Feb vs Jul Highs
22 Feb 2024 05:30 AM
Wednesday featured yet another day of very warm February temperatures with some locations even reaching the lower 70s. Ames topped out at 64°F. Sometimes it is difficult to grasp how relatively warm that is for February. The featured chart makes an attempt at providing a comparison between the high temperature distributions during February and July for Ames. The left panel maps quantiles between the two month's distribution of highs. A value of 64°F during February maps to a high temperature of 102°F during July. Restating, a high of 64 during February happens as frequently as a high of 102 during July. After a brief cool down to values only slightly above average, even warmer weather is expected next week to close out February.
Voting: Good - 12 Bad - 2

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Fri Feb 23, 2024
Ames to Boone
23 Feb 2024 05:30 AM
The distance between the Ames and Boone airport weather stations is only about twelve miles, but sometimes the weather difference between the two can feel like many more. The featured chart is a bit of a deep dive into the difference between the two station's air temperature readings. The top left panel is a simple hourly difference plot between the two sites so far this February. It is not too exciting, but does show some instances of the temperature difference reaching 10 degrees Fahrenheit. The other three panels are where things get a bit more interesting. The bottom left shows the bulk annual statistics of temperature difference with a noticeable smoothing out over recent years, since about 2014. It seems that instrumentation changes are likely to be in play to cause that change in performance, but that is speculation. The top right panel is where things get very interesting and shows the frequency of Ames being warmer than Boone by week of the year and by hour. There is clearly a landuse effect showing up toward the end of May with the Boone station likely feeling the impact of having a large agricultural field to its immediate south. The top right panel also shows a neat effect happening during the early morning hours with the lowest frequencies of having Ames being warmer than Boone found. This has to do with subtle topography issues at the Ames site causing cold air drainage past the site. The bottom right panel shows the distribution of differences by month, which denotes some enhanced variability during the late summer and early fall months. You can generate this chart for two arbitrary airport sites of your choice and for other variables, like mean sea level pressure, which has interesting applications in mountainous regions.
Voting: Good - 19 Bad - 0

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Mon Feb 26, 2024
Red Flag Warning Period
26 Feb 2024 05:30 AM
Monday will start off an active three day period of weather over Iowa with extremely warm temperatures for February along with gusty winds. The combination has prompted the NWS to issue Red Flag Warnings over almost the entire state. These warnings cover dangerous fire weather conditions when warm temperatures combine with strong winds and low relative humidity along with dry vegetation. The featured chart presents the time domain each year between the first and last Red Flag Warning over Iowa. Having such a warning in February is not without precedent with the average start date by the third week of March. A powerful storm system will pass tomorrow and bring a very abrupt change in temperature Tuesday afternoon and into the evening. A cold day on Wednesday along with some snow will rapidly give way to a quick return to above average temperatures again to end February.
Voting: Good - 9 Bad - 0

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Tue Feb 27, 2024
February Record Highs
27 Feb 2024 05:30 AM
It was a record setting day in Iowa on Monday with the following first-order NWS climate sites either tying or setting new February high temperature records.

Having Waterloo and Mason City best their previous February records by seven degrees each is very remarkable! The featured chart presents the current monthly high temperature records for Dubuque. Temperatures will again be quite warm on Tuesday, but take a very abrupt downturn in the afternoon.
Voting: Good - 17 Bad - 0

Tags:   2024   feb  
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Wed Feb 28, 2024
Extreme Six Hour Drop
28 Feb 2024 05:30 AM
For about the eastern half of the state, early Tuesday afternoon featured very warm temperatures with places like Cedar Rapids hitting 70+ degrees for the second consecutive day. This warm air was quickly shunted out of the state by a powerful front and replaced with much colder air along with snow showers. The rapid drop in air temperature and feels like temperature is the subject of today's featured chart showing the top 10 drops in feels like temperature for Burlington (far SE Iowa) over a six hour period. The drop yesterday from 76 to 15 degrees comes in as the largest such drop on record according to unofficial IEM archives and feels like temperature calculations. Wednesday will be a chilly day and then we will rapidly swing back into much above averages temperatures once again on Thursday.
Voting: Good - 14 Bad - 0

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Features for Feb 2024