The meteorological winter season is now behind us, so it is time to see how warm this winter was compared with previous ones. The featured map presents an IEM computed analysis of simple daily average temperature percentile. Think of it as the percentage of previous years that this year was warmer than. A good portion of the state is shown at 100%, which would make it the warmest winter on record for the location. This is all based on preliminary and unofficial data, so caveat emptor.

Update: I have regenerated the image after an off-by-one bug was found. The area at a record is smaller.

After a punishing year of severe weather in 2011, this year appears to be attempting a repeat. The Storm Prediction Center has a very large area outlined for a moderate risk of severe weather today and into Saturday morning. This storm closely follows a deadly storm system on Wednesday that brought tornadoes to Kansas, Illinois and other states. Iowa will miss the severe weather and perhaps get a bit of snow.

Updated the feature graphic to show the 11:30 AM outlook with the high risk.

A major storm system impacted the eastern US on Friday bringing deadly tornadoes to places to our southeast and heavy snowfall as well. The extreme eastern portion of the state picked up the highest totals of around 4-5 inches as shown by the featured snowfall analysis. This snow was accompanied by a very strong wind making for difficult driving conditions. Our next snow producer arrives on Sunday, but totals are expected to be very light. A big warm up is expected during the early part of next week.

Our parade of snow producing storms continued on Sunday with the central portion of the state receiving the heaviest totals upwards of four inches. This snow and the other recent snows will have a difficult time sticking around with much warmer weather expected today and especially on Tuesday. Our next chance of snow comes midweek, but temperatures are expected to remain mild.

After three rounds of snow storms in the past week, temperatures will feel much more like spring today with forecasted highs by the weather bureau in the 60s and 70s! This will be thanks to a strong wind bringing warm air into the state today. Reality comes back tomorrow with a cold front dropping temperatures back to seasonable levels.

Temperatures on Tuesday soared into the 70s for much of the state. For Des Moines, the high of 74 tied a record for the date and was the warmest temperature since the start of winter. The featured chart presents a time series of temperature along with the daily high and low climatology. Our periods below average have been brief and not all that cold. Temperatures this morning are still very warm, but will drop later today with the passage of a cold front.

Our experience with very mild air for early March ended on Wednesday with the passage of a cold front ushering in more seasonable air. The featured chart presents a time series of air temperature for some automated weather sites in the state. Cold front passages like this create a very difficult forecasting situation as the timing of the front greatly impacts the high temperature for the day.

Yesterday was yet another nice day this winter season with mostly sunny skies and near average temperatures. It seems there has been an inordinate number of mostly sunny days this year, but the featured chart would indicate otherwise. The featured chart provides an estimate of the number of days since the first of the year that the reported sky condition by the automated sensor has been mostly sunny around noon time. There are caveats galore with this including the fact that the sensor is not able to report very high level clouds.

Today begins the scam that is daylight saving time with an hour of morning sunlight stolen until this fall. The IEM has previously exposed the time change as a means for business to save money. Today's feature shows the local sunrise time along with the number of days it takes until the sun rises at the same time again later in April. It is just over a month with the process going faster the further north you go. If you look at this plot closely, you may notice the sun rising earlier at Saint Louis than Ames in mid June even though Ames is much further north. The reason for this is simple, but do you know why?

Our next week of weather looks to be nothing short of amazing with high temperatures well into the 70s! This continues the trend of having well above normal temperatures so far this year. The featured chart presents the date on which the reported daily high temperature nearly equals climatology. So having a high temperature in the lower 70s today would feel like average in early May. The colder than average days (the very few that there are) so far this year are shown as well. Some days were colder than the yearly minimum high temperature and are simply drawn to 1 Jan.

We have just started what appears to be a very warm stretch of weather in March. The featured chart presents the warmest periods in March as measured by the minimum high temperature over a given number of days. For example, the coolest high temperature during 1910 was just 40 degrees for the entire month. For Ames, the longest period of temperatures at or above 70 is 12 days and at or above 80 is 4 days. One has to continue to wonder how we will eventually pay for all of this warm winter weather!

High temperatures on Wednesday soared well into the 70s setting records over a good portion of the upper Midwest. The featured map presents the high temperature departure from average showing most of Iowa in the 30 degree range! This warm weather will continue today, tomorrow, the next day and the day after that and the ....

Our remarkable stretch of weather continues with record high temperatures being set over much of the eastern half of the United States. The featured chart shows recent high temperatures for Mason City with the previous daily record being bested by 15 degrees on the 14th. All of this warm weather is happening during the week where many schools are on spring break! At this rate, it may need to be renamed as summer break.

The weather got even warmer on Friday with high temperatures around 80 degrees for much of the Midwest. For some, this is more than 40 degrees above average as shown by the featured image! A number of places have also set records for the earliest occurrence of 80 degrees and the earliest streak of consecutive days over 80. The humidity levels have been on the increase as well with observed dew points being some of the largest ever recorded in March for the area. Today will be yet another very warm day with highs again near 80.

Our epic stretch of March warm continues with temperatures expected to approach 80 degrees again today. Des Moines has hit 80 degrees each of the past four days making for the earliest streak of such warm weather. It was not only the earliest streak, but bested the previous record by a month! The featured chart presents the earliest four day streak of a given temperature threshold for Des Moines. The green line was the record prior to this year. The previous record for 80+ degree days was in mid April!

Our recent stretch of record heat and limited precipitation has warmed our soil temperatures to levels one would expect in late April. The featured chart presents daily time series of four inch depth soil temperatures for each year since 1988. The red line represents this year and shows the unprecedented current soil temperature levels. Sustained temperatures above 50 degrees Fahrenheit are typically considered necessary to plant corn, so our current average temperatures well north of 60 degrees would be sufficient. The problem is that the calendar still says the middle of March and there is plenty of time for cold weather to return or even snow!

Our epic stretch of warm weather continues to rewrite the record books for March. A couple places in the MidWest have experienced something truly exceptional. The low temperature for the day was warmer than the previous record high temperature for the day! The featured chart shows this happening for Rochester, Minnesota on Sunday. The low temperature was 61 and the previous record high for the date was 60! This is an extremely rare event to occur and checking back through the archives of data the IEM has for Iowa, this hasn't happened in Iowa since 26 Dec 1936 (keep in mind that this feat was easier to achieve with fewer years of climatology in 1936).

Numerous places over the eastern half of the country set records again on Tuesday as the epic warmth of March rolls on. The temperature was cool enough to not set another record high temperature for Des Moines and so ending the streak of six straight days with a record high. The featured chart attempts to show the daily record high temperatures for Des Moines and the year during which they were sequentially set. Of course, the first year on record shows up for each date with later years slowly building over top them. The records for this year are shown in bright red. The numerous warm days in the year 1910 show up prominently, which may be the only competition for this year to be the warmest March on record. The numeric value shown on the top of each bar indicates the number of times the daily record has been set. Kind of interesting to note the most frequent days with records set having occurred in the recent period as well, which was probably helped by an initially cold period for the first year on record.

There are many ways that one can express how different our recent weather has been from what we would expect to experience this time of year. Two such methods are shown in the featured graphic for daily high and low temperatures for New Hampton, Iowa. The top graphic is the simple departure in degrees Fahrenheit from the climatological average. High and low temperatures have been around 40 degrees warmer than average, but how exceptional is this? Another method is to compute the standard deviation of the distribution of temperatures for a given date around its long term mean. This value can be used to normalize the raw temperature departure shown in the top chart and is often called "sigma". So how exceptional is a four sigma value? It is roughly a temperature we'd expect to see every 40 years or so. The chart shows that for recent days, the low temperatures have been more exceptional than the highs.

This year has started off being one of the warmest on record. The featured chart presents two computed metrics of accumulated growing degree days and simple average temperature. While the average temperature ranks a close second for Ames, the accumulated growing degree days blow away the competition. It is little wonder that plants are getting going early this year, but the major concern is that there is plenty of time for a hard freeze.

The past two weeks of weather have been much warmer than any measure of normal. Even daily low temperatures have been warmer than our average high as shown by the featured chart. Only a slight cool down is expected in the forecast with highs back in the 60s and lows in the 40s. The payback date for all this nice weather has yet to be determined.

The major concern at the moment is if we will see freezing weather again this spring. The warm winter and extremely warm March have provoked much of our vegetation to grow and a hard freeze now would damage the more sensitive crops. The featured chart presents the last day each spring that the temperature was below 32 and 29 degrees Fahrenheit. While there has been another year with such an early date of the last sub 29 degree day, it seems rather unlikely that we could go through all of April without a freezing temperature below 32. The immediate term forecast continues the warmth, but perhaps a big storm is brewing next week.

As March winds down, it appears Ames will easily set the warmest March on record. The featured chart presents the month to date temperature rank and difference from the previous warmest value. We have been the warmest on record since the 16th and at one point was nearly five degrees warmer than any previous March on record. There are still four days to go and forecasted temperatures look to remain above average.

The featured chart for yesterday showed this March easily being the warmest on record for Ames. Today's chart based on preliminary data shows the current year to date being the warmest on record as well for Ames. The warmth will roll on with temperatures returning to the 80s this weekend.

A thunderstorm complex fired to our southwest Thursday evening and rolled into Iowa overnight dumping some much needed moisture over a good portion of the state. The featured map presents estimated rainfall totals from the NOAA NMQ project for the 12 hour period prior to 6 AM on Friday. Sometimes these estimates can be a bit overdone due to hail contamination, which causes radar based precipitation algorithms to over estimate the amount of water reaching the ground due to the highly reflective hail stones to radar.