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 Mar 2024

Fri Mar 01, 2024
February warmer than March
01 Mar 2024 05:38 AM
For most locations in Iowa and statewide as a whole, February 2024 was likely the warmest on record. Could we have a cooler March than February? The featured chart presents the number of times that a given month was warmer than another month for the same calendar year for Ames. So for the combination of February and March, we find five times that March was cooler with the most recent occurrence happening in 1998. So it is possible. The near term forecast to start March does not have any cold temperatures in sight, so it seems March is picking up where February left off.
Voting: Good - 13 Bad - 1

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Mon Mar 04, 2024
Warmest Winter *
04 Mar 2024 05:30 AM
For the winter season comprising the months of December thru February and considering an average daily temperature, many sites in the upper Midwestern US had their warmest winter on record. As the feature title denotes, there is a bit of an asterisk to this statement. The asterisk is the consideration of the winter of 1877-1878, which is before the period of record starts for the vast majority of long term climate data for the region. The featured table presents some IEM computed winter season average temperature records for selected sites over the region. The warmest value is highlighted. For a number of sites with data for 1877-1878, that winter was much warmer than our most recently finished one. Minneapolis and Milwaukee are exceptions with this winter warmer than the 1877-1878 one. The official NCEI statewide data starts in 1895, so it may end up showing this winter as the warmest on record for a number of states (including Iowa), but that statistic would not include 1877-1878. Another interesting data point is Bismarck, ND, whose warmest winter was 1930-1931 and that even includes the 1877-1878 one.
Voting: Good - 17 Bad - 1

Tags:   winter   2024  
Tue Mar 05, 2024
Earliest 80
05 Mar 2024 05:30 AM
Sunday featured yet another day this cold season with extremely warm temperatures. Waterloo set another daily record by ten or more degrees with a high temperature of 80°F, besting the previous record of 70°F. Cedar Rapids also hit 80°F, besting their previous record of 71°F. Both sites established new earliest-in-year dates for first 80°F temperature. The featured chart presents the first date each year of 80+ degrees for Cedar Rapids and then the total number of days at or above that threshold for the year. Sunday beat the previous earliest date by almost two weeks!
Voting: Good - 9 Bad - 0

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Wed Mar 06, 2024
March Temperature Gradient
06 Mar 2024 05:30 AM
The IEM attempts to collate a number of public datasets into a product called IEM Reanalysis. This product produces a number of daily and hourly grids dating back a number of years. The featured map presents the hourly analysis of air temperature at 22 UTC yesterday (4 PM CST). It shows a strong temperature gradient over the Midwestern US with values below 20°F over North Dakota and values above 70°F over southeastern Missouri. A recently added autoplot featured today allows you to generate maps from the available hourly data. You can also find raw netCDF files available from the aforementioned link.
Voting: Good - 16 Bad - 0

Tags:   iemre  
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Thu Mar 07, 2024
Center Weather Advisories
07 Mar 2024 05:30 AM
To support aviation, the NWS has Center Weather Service Unit (CWSU) offices spread throughout the country. These offices issue a number of products that are archived on this website. One of them is the Center Weather Advisory (CWA). The featured map presents a recent CWA issued by the Minneapolis CWSU for some thunderstorm activity clipping northern Iowa on Sunday. The autoplot tool that generated this map isn't all that functional for public usage yet, so the text interface is one of the better places to find these maps along side the raw issuance text. Additionally, the IEM has a shapefile download option for an archive of these alerts.
Voting: Good - 15 Bad - 0

Tags:   aviation   cwa  
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Fri Mar 08, 2024
Chilly Rainfall
08 Mar 2024 05:30 AM
Needed rain is falling this Friday morning across much of the state and will slowly work its way east through the day. It is a chilly rainfall with temperatures only in the 30s and low 40s. The featured chart presents a heatmap of temperature by week of the year when measurable precipitation was reported by the Ames airport weather station. The line connects the weekly average values and as you would expect, replicates an overall temperature climatology pattern with the warmest values in mid July.
Voting: Good - 12 Bad - 0

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Sat Mar 09, 2024
'23-'24 Winter Storm #12
09 Mar 2024 07:08 AM
While our most recent storm brought mostly rain to Iowa, some snow was observed over far western Iowa. A number of locations met the arbitrary threshold of two inches of snow to get an IEM snowfall map generated, so that's what is featured today. The snow that did fall was slushy and struggled not to immediate melt with soil temperatures quite warm and falling during the daylight hours. Such will be the struggle for any snow that attempts to fall with what remains of this late winter and early spring season. The forecast next week has temperatures back in well above average territory and meager rainfall chances, both of which have dominated this calendar year so far.
Voting: Good - 9 Bad - 0

Tags:   winter2324  
Mon Mar 11, 2024
Another sunny month
11 Mar 2024 05:30 AM
March has followed February's lead with plenty of sunshine and very limited periods of cold temperatures. One measure of the sunshine we have seen these past two months can be found by the featured chart. It presents the monthly frequency of having an "overcast" cloud condition reported at noon at the Des Moines airport. The top panel shows the average monthly frequencies and what has been observed so far in 2024. The bottom panel shows each previous March on record. This week will start off with a good deal of sunshine, before clouds and some rain chances arrive later in the week.
Voting: Good - 7 Bad - 0

Tags:   cloud  
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Tue Mar 12, 2024
Year of Waterloo Records
12 Mar 2024 05:30 AM
For the 7th day this year, a record high temperature was set at Waterloo yesterday with a high of 77°F. The featured chart presents the location of the present day record daily high and low temperatures along with precipitation for Waterloo. The horizontal bars are decade counts. For maximum high and low temperature, the 1930s continues to dominate the period of record records. For precipitation, it is interesting to see that the 2010s leads the way for the site. The record for tomorrow appears out of reach given the current forecast, but temperatures have been exceeding expectations lately.
Voting: Good - 9 Bad - 0

Tags:   records  
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Wed Mar 13, 2024
Min Low after First 80
13 Mar 2024 05:30 AM
Last week, Cedar Rapids reached 80 degrees and exceeded their earliest such temperature by about two weeks. Does having a summer like temperature mean the end to winter like cold? The featured chart attempts to look into that question by plotting the minimum low temperature after the first spring temperature at or above 80 degrees for Cedar Rapids. The middle chart generally addresses this question showing that the minimum temperature is more a function of day of the year than anything else. So an early first 80 is still likely to see a cold winter like temperature.
Voting: Good - 8 Bad - 1

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Thu Mar 14, 2024
HRRR Time Lagged Emsemble
14 Mar 2024 05:45 AM
Instead of just looking at one weather forecast model, meteorologists like to look at an ensemble of models to gain more insight into the forecast. There are a number of ways an ensemble of model forecasts can be put together. One way is called a "time lagged ensemble", which puts together number runs of the same weather model, but each member model starting at a different initialization time. The HRRR model is run every hour by NOAA, with about 15 runs or more available at a given forecast hour. The featured map is from an autoplot tool on the IEM that allows generation of postage stamp plots of time lagged simulated and observed RADAR reflectivity. The top left panel shows the observation at 4 AM this morning with the 15 others showing sequentially lagged HRRR model output valid at 4 AM. Meteorologists can gain some confidence that a model is performing well when each run shows similar forecast features and that those features match reality rather well! In this case, showers and thunderstorms over southeastern Iowa and lighter rain over northern Iowa.
Voting: Good - 13 Bad - 0

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Fri Mar 15, 2024
Busy Severe Weather Day
15 Mar 2024 05:30 AM
The first major and widespread severe weather day of the year happened on Thursday with large hail and tornadoes reported from Texas to Ohio. The featured chart presents an unofficial IEM accounting of the number of Severe Thunderstorm, Tornado, and Flash Flood Warnings active per minute during Thursday. The maximum of 16 simultaneous Tornado Warnings ranked in the top 10 largest for March events since 1986. The chart nicely illustrates the transition that often happens during most severe weather events as night time boundary layer stabilization leads to a decreased severe thunderstorm and tornado threat, while the flash flooding threat increases as rainfall totals pile up and thunderstorms train over the same locations.
Voting: Good - 13 Bad - 1

Tags:   warnings   load  
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Mon Mar 18, 2024
2024 PRISM Departures
18 Mar 2024 05:30 AM
The last half of March and April is an important time for rainfed agriculture to replenish soil moisture reserves prior to the start of the growing season. The featured map checks in on how things are going so far this year for Iowa by plotting PRISM precipitation departures from average so far this year. About the southeastern third of the state has fared the best so far with far northern Iowa showing the largest below average values. Drought continues to be a significant concern and while some precipitation is forecast to fall this week, amounts do not appear to be much higher than climatology.
Voting: Good - 9 Bad - 0

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Tue Mar 19, 2024
Accumulated Snowfall
19 Mar 2024 05:30 AM
The featured chart presents season to date snowfall accumulations for Des Moines. The tan area represents the range of data over the period of record. The black dashed line is the climatology / average accumulation. The blue line represents the largest snowfall total for the season and brown the least. The red line is this year and green line is last year. Remarkably, this year, last year, and the climatology value are all about equal for the 19th of March, but have taken remarkably different paths to get there. This season experienced just a few major snowfalls back in January with meager totals from other storms. Last season was more methodical with many snowfalls adding up with time.
Voting: Good - 0 Bad - 0

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Features for Mar 2024