OMAHA (DTN) -- Iowa is not the only state in the Western Corn Belt, but the state's conditions set the tone for the region. In these last two weeks of 2012, Iowa's veteran state climatologist has some concerns about how soil moisture supplies will finish this year.
"The fall season precipitation was somewhat disappointing," said Harry Hillaker. "The extreme northeast corner had above-normal totals since Sept. 1. The rest of the state, especially the far northwest, is really dry."
Hillaker's records show the far northwestern sector of Iowa -- north of a line from near Sioux City to just north of Mason City -- received less than half the usual fall precipitation.
"We saw less than three inches in that section," he said. "Normal spring rain would not be even close to getting soil moisture back to field capacity in that area. So, we'll likely start out the spring season behind on soil moisture."
Elsewhere, soil moisture is generally below normal, with some potential for enough improvement by planting time in 2013 to offer crops a decent start. Hillaker is guardedly optimistic about the eastern one-third of the state -- an area bounded by a north-to-south line from Waterloo to Ottumwa and then east to the Mississippi River. "Most of this area has been close to normal for fall precipitation; it's not enough to get to field capacity, but this area should be able to get there by spring," he said.
The remainder of Iowa -- the central, north-central, south-central and southwest crop reporting district -- "probably will be a little on the short side come planting, but at least halfway decent," Hillaker said. "Fortunately, it would not take record-breaking rains to get to normal (soil moisture supply)."
One environmental factor that may play a part in the moisture recharge scenario is a very mild temperature trend up to this point. This year is the second-warmest on record in Iowa (the warmest year was 1931), and the mild temperatures mean very little frozen ground so far.
"There is a reasonable chance that we'll have a bit longer recharge season," Hillaker said. "And, depending on the track of the snowstorm (Dec. 19 to 20), if we had snow of around three inches minimum, all the state would benefit; even far northwest Iowa would have some moisture soak in."
Soil moisture supply recharge during winter and spring is critical, Hillaker said. "After the first of June, you start losing moisture during the day," he noted. "And, considering we had such a huge drought area across the country this year, once you get into the last of spring into summer, that lack of soil moisture can result in lower humidity and a more difficult time of it to get rain. That's not a big deal this time of year, but it becomes a real issue in spring and summer."
In the past 45 years, Hillaker's records show the only drier years than 2012 in Iowa were 1988, 1989 and 1976.
Bryce Anderson can be reached at firstname.lastname@example.org
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