The weather pattern that has brought unseasonable warmth to Indiana and kept the state relatively dry since January is expected to stay for a while longer yet, the Indiana State Climate Office says.
"What you see is what you get," said state climatologist Dev Niyogi, based at Purdue University. "Our outlook is for more of the same. We've got a pattern going on here."
Although flowers in home gardens are blooming, trees are showing signs of green and farmers are heading into their fields to prepare them for planting, that doesn't mean the outlook is all rosy. There could be frost at any time, and there is a higher-than-normal risk of severe weather, including tornadoes and thunderstorms, Niyogi cautions in the State Climate Office's Spring 2012 Outlook.
While above-normal temperatures should continue through the next three months and the current drier trend persists at least through early spring, precipitation is expected to return to normal in May and June, according to the outlook.
The summerlike weather is largely the result of a "positive Arctic Oscillation," a pattern that locked cold air in Canada rather than moving it to Indiana. In addition, La Niña's typical pattern of sending Indiana wetter and cooler weather well into the spring already is ending; it went into June last year, delaying farmers from planting crops for many weeks.
The Arctic Oscillation has been more of a major player throughout the winter and now, said associate climatologist Ken Scheeringa. "AO dominated La Niña and gave us the opposite effect of a year ago," he said.
As of March 27, the state average temperature for the month was 54.2 degrees Fahrenheit, nearly 15 degrees above normal and so far the warmest March on record in Indiana since 1895.
The weather has been so good that some farmers hit the fields in early March to prepare them for planting. Some have even planted their corn already, a risky venture since it typically is not planted until mid-April when there is less threat of a destructive freeze. Farmers with some types of crop insurance would lose the replanting portion of their coverage if they planted before April 6 - if the crop were damaged and needed replanting, insurance would not cover the cost.
Farmers planting now also are, in effect, extending their growing season by a month, running the additional risk of having to contend with more weeds than normal later in the season.
But at least for now, a sight to behold has been garden plants in bloom so early.
Spring blooming plants have "a tremendously early and spectacular display this year," said Purdue Extension consumer horticulture specialist Rosie Lerner in West Lafayette. "It's as if the season is on fast-forward, bringing nearly everything into bloom all together."
Barring any unusual weather, Lerner said a frost or freeze will not kill plants whose primary ornamental feature is flowers.
"However, there certainly could be injury to foliage and young twigs; likewise for herbaceous perennials and hardy annuals," she said. "Except for conifers, plants that lose leaves or leaf buds will produce new ones."
Fruit crops such as apples, peaches, grapes and strawberries have been developing rapidly because of temperatures in the 70s and 80s. But that has put crops in a sensitive stage, especially in the event of a cold snap with temperatures at 28 degrees or lower.
Such sudden drops in temperature are more related to weather conditions on a particular day even amid an overall trend of warmer weather, Scheeringa said.
"A freeze event can be related as more of a snapshot of what's happening on a specific day than to a longer trend," he said. "It is quite unpredictable."