Growing Season 2013: Better for Corn Belt, Northeast Fruit
By Mel Fabrikant Thursday, March 14, 2013, 07:56 PM EDT
Below is a breakdown of AccuWeather's spring forecast and how the weather will impact agriculture across the U.S.
Good News for Agriculture From Plains to East Coast
The arrival of rain and snowstorms this winter and ongoing into March has paved the way for a more positive outlook into the early summer from parts of the Plains to the East Coast, where much of the nation's corn is grown.
A bumper crop of corn alone later this summer could eventually reduce the pressure on grain, livestock feed and many consumer prices in general.
Compared to last year, for the season as a whole, more moisture will be available for agriculture due to lower temperatures and lower evaporation rates from the Mississippi Valley to much of the Atlantic Coastal Plain.
Dry Weather May Hurt Agriculture in the Rockies, California, Florida
Building heat and dryness may be a problem from portions of the High Plains to the foothills of the Rockies. Drought may build over California. Dry conditions are likely to worsen over the Florida Peninsula into the first part of the summer, before reversing later.
More Snowcover Means More Moisture for Agriculture
Storms in recent months has delivered near-normal snowfall from major crop-growing areas of the lower Plains through the Midwest and in parts of the Northwest.
The magic of gradual melting snow releasing the water locked up therein through the coming weeks will seep in slowly, reaching deep into the ground. Runoff will fill streams and rivers.
There are some concerns, however.
According to Western Weather Expert Ken Clark, "A lack of big snowstorms over the Sierra Nevada and other ranges in the West could mean water resource limitations in California."
Big snow during the spring last year brought snow water content close to normal in the northern Sierra Nevada. However, in central and southern parts of the Sierra Nevada both last year and this year have been below normal in snowfall and the locked up water within that snow, based on data from the California Department of Water Resources.
Senior Meteorologist and Geography Expert Jim Andrews added, "Less-than-average snowfall this winter in the central and southern Rockies and normal to abnormal dryness this summer could result in reduced water levels on the Colorado River."
The Colorado River winds its way from Colorado and Wyoming to Arizona and supplies water to various sources from agriculture to hydroelectric along the way.
Tipping the Scale From Drought to Flooding?
Sudden localized heavy rainfall (with or without a large existing early spring snow pack) or the lack of average rainfall can easily tip the balance toward flooding or drought. Sub-regional variances of this nature are beyond the scope of this story.
One area to watch for flooding over the next few weeks is southeastern New England. However, this is not considered a major crop area.
A few rivers from the central Plains to the Upper Midwest may be running near bank full with minor lowland flooding possible into the end of the March, due to episodes of melting snow combined with rainfall.
This is quite a turnaround from last year. Even the upper Mississippi River at St. Louis, Mo., was approaching action stage during the second week of March, after flirting with near-record lows much of the winter.
Lower Threat for Damaging Late-Season Freezes
According to Paul Pastelok, head of the AccuWeather.com Long Range Department, "Temperatures are likely to average above normal for much of the nation this spring and summer. However, to put things in perspective, most areas from near the Mississippi River to the Atlantic coast are likely to average cooler than last year during the two seasons combined."
Average temperatures are significantly lower this March, when compared to last March for much of the nation. While this will translate to lower soil temperatures, it will also result in lower evaporation rates for a time.
Overall, less long-lasting, extreme heat is forecast from the Mississippi Valley to the East during most of the spring and summer.
Lower temperatures in the northern Plains, Midwest and Northeast during the winter and in March, when compared to last year, will mean a slower spring for budding.
According to Agriculture Weather Expert Dale Mohler, "One negative is that generally crops are likely to be planted later this year, when compared to last spring."
Some farmers may not get two crops in.
"Lower temperatures and/or wet conditions would play a role in delayed soil preparation and planting," Mohler said.
Slower budding when compared to last year around the Great Lakes and Northeast should reduce the risk of freeze damage to fruit trees, grapes and berries, to name a few.
Expert Senior Meteorologist Brett Anderson had this to add, "As far as apples are concerned around the Great Lakes and Northeast, lower yields last year and less stress this spring and summer could result in the stored energy, to be released in the form of a bigger crop this year."
"We expect ample moisture during most of the growing season, with few exceptions into this summer from the Mississippi Valley to the East Coast," according to Pastelok.
The long-range team anticipates occasional storms rolling in from the Northwest, tracking into the Midwest, where they will gather moisture from the Gulf of Mexico and deposit it liberally well into the spring.
There is always a risk of a late-season snowstorm. However, the risk may be a bit greater this year for parts of the Great Lakes, mid-Atlantic and Northeast.
"During the late winter, there has been an ongoing tendency for a blocking pattern with winds high in the atmosphere (the jet stream). This pattern may continue to re-appear well into the spring in some areas," Pastelok said.
Moving into April, such a pattern can cause part of the jet stream to break off, producing a colder storm with snow farther south than you might expect. Typically, these storms produce wet snow in only a small area that is often elevation dependent, and the snow rapidly melts the following day.
From Alabama to the Carolinas, there has been enough rainfall over the winter to all but wipe out the drought that started last summer.
According to Southern Weather Expert Dan Kottlowski, "Waters over much of the Gulf of Mexico are running cooler than last year, and it is possible that if this trend continues for a while longer it could continue to take the edge off the intensity of severe weather in the South well into the spring."
How Do Thunderstorms Play a Role?
A perennial key player for agriculture over the Plains and Midwest is the frequency and distribution of thunderstorm complexes, known to meteorologists as Mesoscale Convective Systems (MCS's) or Mesoscale Convective Complexes (MCC's). These systems can resemble a tropical storm over land, pull moisture from the atmosphere and deposit it in the form of drenching downpours than can travel along for hundreds of miles spanning the late spring to midsummer.
A lack of these complexes last year (less the June Derecho event) caused the drought to worsen. With less moisture in the ground during the late spring, more of the sun's energy was directed to heating the ground and in turn heating the air in the lowest levels of the atmosphere.
"We expect a near-normal number of these complexes over the Midwest and in the lower part of the Plains. However, these may be stingy farther west over the High Plains," Pastelok said.
The long-range team feels that a more prominent low-level flow of moisture will be present from the Gulf, feeding the complexes farther north over the Plains.
AccuWeather Enterprise Solutions Senior Vice President Mike Smith is cautiously optimistic about the weather for winter wheat over the Plains.
"A significant portion of the crop could be harvested from south to north before it would get too dry," Smith stated.
Smith also reaffirmed the challenge of long-term forecasting of localized and regional thunderstorm complexes.
Some wheat and grazing areas on the High Plains (just east of the Rockies) are still in exceptional drought despite recent storms or could develop serious problems very quickly this spring should thunderstorm complexes fail to show up. Wheat concerns are discussed more extensively in: "Blizzards Bring Drought Relief to Wheat Belt."
Summer Outlook and Agriculture
This summer, the AccuWeather long-range team expects the typical zone of high pressure at most levels of the atmosphere over the Rockies to expand eastward over the Plains and westward toward the Pacific Coast. The extent of this will determine the areas of drought, heat and ample moisture, including the extent of the Southwest Monsoon later.
Prior to this blossoming of the high, which represents a northward bulge in the jet stream over the Rockies and High Plains, some heat and dryness may nose eastward.
"A surge of warmth and perhaps dryness is most likely to occur in June for the Midwest and parts of the East," Pastelok stated, "prior to the development of the northward jet stream bulge."
Once the bulge develops in the West, it is likely to allow a southward dip in the jet stream farther east in part of the Midwest and Northeast. This would favor less extreme, long-lasting warmth and an uptick in summertime showers and thunderstorms during July and August.
In the South, high pressure at most levels of the atmosphere will inhibit rainfall into June over the Florida Peninsula. However, slight cooling is likely aloft in the Eastern states from midsummer on, due to the building high in the West. It should remove the lid from the pot of tropical thunderstorms.
Over the South Central states, Pastelok expects a sufficient flow of moisture from the Gulf of Mexico, combined with the ever-present heating from the sun to provide occasional showers and thunderstorms. Plus, many of these areas will be going into this season with much more moisture than they had last year at this point.
In the Northwest, Pastelok's team expects the region to dry out faster this summer, when compared to the wet start during the season last year.
"We are in a neutral phase of the El Niño Southern Oscillation (ENSO) at this time and we expect this to continue moving into the summer," Pastelok said, "As a result, we expect little change overall in the temperature departure and precipitation departure pattern we are in entering the spring."
Very Early Speculation on Hurricane Season
Early last season, warm waters in the Gulf of Mexico and the nearby Atlantic helped to fuel a bumper crop of early season of tropical storms.
"If we look at the current neutral ENSO combined with the cool waters at present and if they continue into June, we could start with lower numbers of named systems once we hit midsummer, which could weigh in for the season as a whole," Pastelok said.
Pastelok is pondering the possibility of a tropical system popping up in June over the eastern Gulf of Mexico.
"There is room for a system to develop on the back edge of the ridge of high pressure in the area," he added.
By then, water temperatures may have recovered to levels sufficient to begin to favor tropical development.