May 18
Eye on the sky PDF Print E-mail
Written by Nancy Jorgensen   
Tuesday, 31 January 2012 22:13

Farmers love to talk about the weather. After all, your living depends on it. Meteorologists find it difficult to accurately predict weather for more than seven days. But we asked Tony Lupo, a climate scientist from the University of Missouri, to go out on a limb and forecast trends in MFA’s region through the spring planting season.

“With La Niña leaving us, our spring should be a bit warmer and dryer than normal,” said Lupo, department chair and professor of atmospheric science. For most farmers, his forecast represents a welcome relief from last year, when wet conditions in some areas delayed planting and lowered yields. 

Lupo’s outlook comes with a warning: “Spring and fall are hard to forecast because they are transition seasons.”
La Niña may bring fairly normal spring

Like Lupo, Ed O’Lenic of the National Oceanic and Atmospheric Administration makes long-range forecasts. But O’Lenic’s forecast varies slightly—he sees a normal to slightly wetter-than-normal spring for Missouri and surrounding states.

“We’re in a La Niña weather pattern, which tends to make it wetter and cooler in the northern U.S., and warmer and dryer in the South,” said O’Lenic, chief of the operations branch for NOAA’s Climate Prediction Center. “Missouri lies in between, but our models favor slightly above normal precipitation, at least for eastern Missouri, through spring.” By slight he means 0.1 to 0.2 inches more than normal—not much. States to the east, like Kentucky, should see greater increases. It’s more difficult to forecast precipitation than temperatures, he added.

According to O’Lenic, we’ve had 20 La Niñas since the 1950s, and each has involved stronger-than-average Trade Winds pushing warm tropical Pacific Ocean currents to the West. “La Niña is expected to last through spring,” he said. “After that, forecasts become more difficult.” 

Still, we managed to squeeze a summer forecast out of Lupo. “We’re in our second year of a La Niña,” he said. “It seldom lasts through a third year.” Normally, an El Niño replaces a La Niña. El Niño brings warmer-than-normal sea-surface temperatures to the tropical Pacific Ocean. “If El Niño develops as expected, we should see a little more moisture than normal this summer, and it won’t be quite as hot,” he said. “El Niño has always suggested a more favorable growing season for Missouri—a mild summer with ample rain.”

Average annual rainfall varies considerably across our region. Missouri ranges from 35 inches in the driest area, the northwestern corner of the state, to about 52 in the Bootheel, the wettest, southeastern corner. Neighboring states closest to Missouri reflect this variation. Iowa averages 34 inches statewide, and Arkansas, about 50 inches. Eastern Kansas receives about 40, and eastern Oklahoma, 56.

Lupo says that La Niña doesn’t bring any more or less rain compared to El Niño—it depends on where you’re located. “During La Niña, the bigger storms are further north in Missouri and across to New York and New England,” he said. “During El Niño, the bigger storms are across southern Missouri, Tennessee and Virginia.”
States to the west and the south, like Oklahoma and Texas, shouldn’t expect relief from their drought until summer at the earliest, Lupo added.

Storm clouds ahead?

After last spring’s devastating tornado in Joplin, Mo., along with media coverage of other major tornadoes, hurricanes, blizzards and ice storms, it might seem like we’re seeing more extreme storms.

Lupo thinks part of that impression is due to the nature of media coverage. In his view, we don’t always hear about tornadoes until they affect large groups of people, like in Joplin. “Cities make up only about two or three percent of the land mass in the U.S.,” he said, adding that he believes that storms like the Joplin tornado are actually happening less frequently. “After 25 to 30 years, statistics catch up with us, and major cities get hit.”

As an atmospheric scientist, Lupo studies large-scale atmospheric dynamics. He specializes in something he calls blocking, where the jet stream stalls over large areas—usually the ocean, but sometimes over large landmasses like Asia. “We see the effect of blocking more in the West where the jet stream stalls and causes cooler and wetter weather, and in the East where we see colder weather,” he said. “In Missouri, we get an indirect effect.” 

In coffee shops and sale barns across the country, farmers are known to express strong opinions about the weather. No matter where you come down on trends in storm intensity, La Niña and blocking, chances are you might agree with Lupo’s final observation about weather in these parts: “Missouri tends to be a place of extremes—we either get too much moisture or too little.”

What can you do?

You can’t change the weather, but you can prepare for it. Zach Paul, a meteorologist for mid-Missouri TV station KRCG, offers advice on using apps available on your smart phone to track the weather. Paul recently provided a guide to such apps, including the Weather Channel, Accuweather and WeatherBug. MFA Incorporated’s Agri Services sites host live weather with a click-to-animate option that is helpful to anticipate the good news (or bad news) of coming precipitation.
For the apps, “The good news is that the free versions of these apps do a good job of providing basic weather information,” Paul said in a recent online column. “For most smartphone users, these apps will give you everything you are looking for—a forecast, current conditions, radar and severe weather alerts.” He also pointed out that KRCG offers WeatherCall Mobile.

“What I use most are the radar apps,” Paul said in a recent interview with Today’s Farmer. “If you’re willing to spend a couple bucks, both Pykl and RadarScope are great applications for tracking rain and storms.” Radarscope dominates the iPhone market and recently became available for Android, he added.

For a weather app designed for farmers, Farm Progress offers online mobile alerts. Visit farmfutures.com/customPage.aspx?p=291

These types of applications, also available for your computer, will notify you in case of National Weather Service alerts. NOAA also offers its radio service as a phone app. The alerts include severe weather watches, when conditions are favorable for severe weather; and severe weather warnings, which indicate severe weather in the immediate vicinity.
Paul pointed out that most apps don’t offer real-time updating. “This means that the delivery of an important message can be delayed,” he said. “The best product in my mind is WeatherCall, compatible with any type of phone, not just smart phones. I strongly believe this product is very successful at saving lives.” WeatherCall, which costs $10 to $12 a year, uses technology to closely match the warning with your location. For more information, visit www.weathercall.net.

Beyond phone and computer apps, you can prepare for the weather in other ways:
•    Weather radios will also notify you of National Weather Service alerts.
•    You can track recent weather in your area at a University of Missouri weather station. Visit agebb.missouri.edu/weather/stations.
•    You’ll find NOAA’s long-range forecasts online at www.cpc.ncep.noaa.gov
•    Buy a generator to keep the lights on in case the power goes out.
•    Manage weather risk by purchasing crop insurance.

As Missouri’s state climatologist, Patrick Guinan tracks historic climate trends. He shared a number of them with Today’s Farmer.

“These historic trends provide snapshots of temperature and precipitation patterns over the past century, as well as the year-to-year, decadal and multi-decadal variability of Missouri’s climate,” said Guinan, assistant professor of climatology with the University of Missouri Extension Service in Columbia.

Warmer over past 13 years

Missouri’s most recent warm annual temperature trend began in 1998. Ten of the last 13 years have been above normal. The 1930s ranks as Missouri’s warmest decade on record.

When you look at seasons, Missouri’s winters have experienced the greatest warming trend. Fifteen of the past 23 winters have been above normal, and four out of the five warmest winters on record have occurred since 1991.

Of the four seasons, springs show the second-biggest seasonal warming trend. There have been only two colder-than-normal springs since 1998.

The 1970s still rank as Missouri’s coldest and snowiest decade.

But spring frost dates defy the other warming trends. The median last spring frost date in Missouri has occurred about three to four days earlier over the past 30 years compared to the long-term average.

Prior to the past couple of years, Missouri hadn’t witnessed an exceptionally hot summer in 30 years.
While winter temps may be warming overall, the cold snap from Jan. 1-10, 2010, was our coldest 10-day period in more than a decade. Similar cold periods occurred in 1996 and 1997. Missouri saw some of the coldest winters on record from 1976 to 1979.

Precipitation above normal
Beginning in the early 1980s, an unprecedented wet period evolved. Since 1982, 20 out of 30 years have had above normal precipitation.
2008 was Missouri’s wettest year on record, with 57 inches of annual precipitation.

Over the past few decades, all four seasons have witnessed more above-normal precipitation years in Missouri—most notably in winter. Twenty out of the past 29 winters recorded above-normal precipitation.
Since 1970, 68 percent of the years have experienced an above-normal number of days with measurable precipitation compared to the long-term average.

The past few decades have seen an above-normal trend in heavy (more than one inch) and extreme (more than three inch) precipitation events compared to the long-term average.
Twenty-eight co-op weather stations have been reporting daily precipitation for 116 years, since 1895. Half of these stations have broken all-time 24-hour precipitation records since 1973.

Natural disasters more prevalent
Over the past decade, we have seen an uptick in natural disasters due to ice storms, tornadoes, floods and snowstorms, but that doesn’t mean the trend will continue.

Missouri recorded 65 tornadoes in 2010, the eighth-highest on record since 1950. In 2006, we recorded the highest number, with 102. On average, the state experiences just over 30 tornadoes a year.

About 50 percent of our tornadoes occur during April and May, but tornadoes can occur any time of the year.
Tornadoes can occur any time of day, but 83 percent come between noon and midnight.

Last April’s Joplin tornado was one of the most devastating in world history. It took more than 160 lives and cost more than $2 billion.

Missouri sits on a line between the cold north and the warmer south, and we frequently see ice storms as a result. In January 2008, an ice storm of historic proportions hit northwestern Missouri, with ice as thick as one inch on trees, power lines and vehicles.

Storms that deposit ice from .75- to 1-inch thick are rare, occurring about one in every 50 years. A similar ice storm hit southwestern and south-central Missouri in January 2007.

For more information, see Guinan’s summary of significant weather events during the 20th century, www.climate.missouri.edu/sigwxmo.php