Iowa Environmental Mesonet Daily Feature

Woefully short

akrherz@iastate.edu (Daryl Herzmann)

Outside of a warm week or two this growing season, there was not much heat to speak of and our growing degree total was some 400 units short of average. The record cold in July really hurt as it should be the month where we accumulate the most GDDs. A very wet October did not help the still standing crops any as mold is now a major problem with the corn and soybean crops.

Warnings per month

akrherz@iastate.edu (Daryl Herzmann)

The featured chart displays the monthly number of severe thunderstorm and tornado warnings issued by the National Weather Service for this year and last. In general, the number of warnings is down this year compared with 2008. The most significant difference is the number of tornado warnings in May being half of the total for 2008.

Avoiding Flooding

akrherz@iastate.edu (Daryl Herzmann)

The featured chart is a time series from the Squaw Creek river gauge in Ames for this year. Unlike 2008, Ames has avoiding any major flooding with only a few events of at bank full. The recent heavy rain last week caused the river to rise, but nothing significant for Ames.

Staying above the trend line

akrherz@iastate.edu (Daryl Herzmann)

The featured chart is a comparison of the accumulated rainfall for this year and last along with the climatological accumulation. In general, the running total for this year has remained above the climatology with the heavy rainfall in October pushing us well north of average again. We are still a ways from repeating 2008, which is a good thing.

Record October

akrherz@iastate.edu (Daryl Herzmann)

The big story for October was the record breaking amount of rainfall observed for the month. The featured image is an IEM estimated rainfall percentile showing most of Northern Iowa at 100, which means the highest amount on record. Thankfully, November is starting off mostly dry with only a few light showers expected this week.

Rainy Thursdays

akrherz@iastate.edu (Daryl Herzmann)

The featured chart is the reported daily rainfall from the Ames Airport for October. The month has been extremely wet with now the third day this month with over an inch of rain. This has previously only happened twice before in Ames for October back in 1931 and 1934. There is some hope in the forecast with mostly dry weather expected for the next week.

Too muddy to harvest

akrherz@iastate.edu (Daryl Herzmann)

The feature map is a model's estimate of near surface soil moisture content. Our recent stretch of wet weather has left the top soil saturated with water, which prevents harvest machinery from entering the fields. Rain showers are lingering this morning in Iowa with a better chance of rain expected mid-week.

Rain all day

akrherz@iastate.edu (Daryl Herzmann)

Thursday was pretty much a wash out with it raining nearly the entire day for some locations in Iowa. The featured map is an estimate based on NEXRAD data of the number of hours it rained on Thursday. Rain continues this Friday morning and is expected to clear out by later this evening. The next chances of rain arrive Saturday night and again next Tuesday.

Two Sigma Weather

akrherz@iastate.edu (Daryl Herzmann)

The featured chart plots the number of days per year that experienced a high or low temperature exceeding two standard deviations from average for Ames. For example, some of last week's cool high temperatures in the 40s were two sigma below average. This chart is an attempt to quantify how "extreme" a given year was. In general, the highest values were prior to 1940 which is probably a reflection of the data quality for that period, although the very hot years in the 1930s show up nicely in this chart.

Tough to harvest

akrherz@iastate.edu (Daryl Herzmann)

The feature map is the 5 day forecast of precipitation from the HPC. Numerous rounds of showers are expected into the weekend, which is not good news for the large amount of corn and soybean crop yet to be harvested. This is all thanks to an active weather pattern that looks to persist into next week.

Lack of persistent warmth

akrherz@iastate.edu (Daryl Herzmann)

High temperatures soared on Monday to values above normal for this time of year. The featured chart looks at the largest stretch of consecutive days with the high temperature above average per year for Ames. So far for 2009, the best we did was 11 days. Our current streak stands at a mere one day with today expected to make it two. Rain and cooler temperatures are in the forecast, so the current streak will not last.

Nice warmup on Sunday

akrherz@iastate.edu (Daryl Herzmann)

Clear skies and warm winds finally broke us out of the recent stretch of dreary days. The featured map displays the magnitude of the warmup yesterday with values around 30 degrees common. Highs today are expected to be warmer than Sunday in the lower to mid 60s, which is above average for today!

Below average lows

akrherz@iastate.edu (Daryl Herzmann)

The featured chart displays the yearly net total of days above average for low temperature (negative values would mean that more days were below average than above). So far in 2009, Ames has seen 50 more days below average for low temperature. This is roughly the largest negative value we have seen in the last 40 years, granted there are 2.5 months left to this year yet.

Reports of Snow

akrherz@iastate.edu (Daryl Herzmann)

The featured map displays the NWS COOP network reports of snow so far this fall season. Most of the Upper Midwest has already seen flurries or measurable snowfall this season, which is rather impressive considering it is only October 15 and most of this same area usually is just now seeing its first frost. The good news is that slightly warmer weather is on the way!

Record cold start

akrherz@iastate.edu (Daryl Herzmann)

The featured chart compares the average temperature for the first 13 days of October for this year with the previous coldest start and the long term climate average. This year has seen temperatures more than a degree colder than any other on record and some ten degrees colder than average. The forecast does have hope for a warmup this weekend into next week.

Taking a nose drive

akrherz@iastate.edu (Daryl Herzmann)

The featured graph is a recent time series of average daily four inch depth soil temperatures from the Ames site along with its climatology. Our stretch of cold air temperatures has helped to allow soil temperatures to cool from the 60s to low 40s. Relatively warm soil temps are a good thing to prevent snow from sticking around very long, but it is only a matter of time before soil temps freeze and the snow will have a chance to stick around for the winter.

Growing Season is Over

akrherz@iastate.edu (Daryl Herzmann)

Thanks to an absolutely frigid weekend for this time of year, the growing season is effectively over with most of the state having experienced a killing frost by now. The featured map shows the lowest temperatures observed from the automated sensors this fall with perhaps only the far southeastern tip of Iowa yet to have the killing frost.

Early snow!

akrherz@iastate.edu (Daryl Herzmann)

The IEM Freeze application nicely shows NEXRAD returns over areas where the air temperature is well below freezing this morning. Sure enough, that is snow and for the calendar only being the 10th of October, it is a bit early. Des Moines tied its record for the earliest measurable snowfall date.

Looking forward to Saturday

akrherz@iastate.edu (Daryl Herzmann)

The featured map is NOAA's National Weather Service forecast for high temperature on Saturday showing most of the state in the low to mid 40s! Flurries are also in the forecast as winter now seems all too close in time.

Cool October Start

akrherz@iastate.edu (Daryl Herzmann)

As the feature title suggests and the chart indicates, October has started off on the cool side with high temperatures well below the climatological average in the upper 60s. The forecast has very little hope of warmer weather and even indicates a chance of snow coming this weekend along with very cold temperatures for this time of year! The good news is that any snowfall will be light and have no chance of sticking around as ground temperatures are still relatively warm.