Published on: Jul 26, 2012
Janell Baum
As crop conditions continue on a downhill slide, some meteorologists are skipping the comparisons to the 1988 drought and jumping right into Dust Bowl data.
Meteorologist David Call of Ball State University in Muncie, Ind., said the Dust Bowl is a good comparison to 2012, as 1988's drought wasn't as widespread.
"Every state in the continental U.S. has some portion of it in some state of abnormally dry or drought level," Call said. "It's not uncommon for there to be dry areas, but this drought is a stretch so far."
He said that the two major droughts in the '30s (1934 and 1936), affected nearly the entire country, much like the drought of 2012. But, he said, they were a little different.
A Ball State meteorologist says this drought may rival those of the Dust Bowl years.
"I suppose one could argue that 1934 was drier while 1936 was a hotter, but that's like trying to compare Peyton Manning and Tom Brady – either drought would easily make the first round "Drought Hall of Fame" ballot," Call said.
Anyway, it's bad. According to the latest U.S. Drought Monitor data, more than 55% of the contiguous U.S. is in moderate or worse drought conditions, a trend that is expected to continue.
And, that limited rainfall coupled with record heat means crops are continuing to suffer. The latest USDA crop condition reports show 21% of the nation's corn crop in very poor condition and only 3% rated as excellent.
Shattered Records
While it is hard to tell exactly when drought worries started to intensify, this spring ushered in a host of record breaking temperatures.
"This whole drought started very early," Call said. "In the month of June, we set thousands of temperature records across the country. Whatever state you were in, you were probably setting records."
While record temperatures caught our attention, it was the lack of rain that really made us watch.
Call said Palmer Drought Indices are one way meteorologists assess rainfall and drought conditions. He said that this measure compares rainfall by rank, and explained that only about 10% of years were drier than this year in all but a dozen states, roughly. Indiana's rank is 3%, meaning it has only experienced drought conditions worse than this year about four times.
"For most states, the Palmer Drought Index, which goes back to 1895, ranks this drought among the top 10 or so years—so far," Call said.
It's That Darned Evaporation
Call said that even with a few good rainfalls, the intense heat and summer sun could shatter dreams of a quick recovery—and fall may be our earliest hope.
He said one of the reasons this drought has been so bad is because of the critical time it went from being a little worry to a big concern.
"One reason this drought came on suddenly was because not only was it dry, but it was very hot," Call said. "When it's very hot, there's a lot of evaporation and plants become stressed much more quickly because they are losing a lot more moisture to the air."
And, the drought seems to cause a lot more problems than just zapping moisture from plants—it can also create a cycle of dryness.
During the late summer, a lot of moisture in the air actually comes from crops, Call said. Without that moisture, it is more difficult for rainstorms to develop.
"The sun is very intense and it's very warm. Even if it starts raining a bit more, [the sun] will evaporate a lot of that moisture and it's not going to go into the ground as much as it would this fall," he said.
As fall temperatures arrive, Call expects the precipitation to go more quickly into the ground and accumulate more easily.
When Will It End?
Though he said predictability is very limited with droughts, Call estimates that if most states get an inch to two inches of rain a week for the next couple of months, things may start to look up by September.
But, he reminded, expectations for a changing weather pattern aren't high—a tropical system or sustained rainfall would be needed to change the drought trend. Call said neither is very likely, and estimated that most states need nine to 12 inches of rain to fully erase the effects of the drought.
Though the drought may continue into fall and winter, drought isn't as noticeable during those seasons. Consistent rains in the spring may be the best bet for a full recovery. Call said that if that happens, residual effects for next year's growing season could be minimal.
"If there are consistent rains in the spring, even if there is a deficit from the past, that should be sufficient for crops to grow," he said.
"I suppose one could argue that 1934 was drier while 1936 was a hotter, but that's like trying to compare Peyton Manning and Tom Brady – either drought would easily make the first round "Drought Hall of Fame" ballot," Call said.
Anyway, it's bad. According to the latest U.S. Drought Monitor data, more than 55% of the contiguous U.S. is in moderate or worse drought conditions, a trend that is expected to continue.
And, that limited rainfall coupled with record heat means crops are continuing to suffer. The latest USDA crop condition reports show 21% of the nation's corn crop in very poor condition and only 3% rated as excellent.
Shattered Records
While it is hard to tell exactly when drought worries started to intensify, this spring ushered in a host of record breaking temperatures.
"This whole drought started very early," Call said. "In the month of June, we set thousands of temperature records across the country. Whatever state you were in, you were probably setting records."
While record temperatures caught our attention, it was the lack of rain that really made us watch.
Call said Palmer Drought Indices are one way meteorologists assess rainfall and drought conditions. He said that this measure compares rainfall by rank, and explained that only about 10% of years were drier than this year in all but a dozen states, roughly. Indiana's rank is 3%, meaning it has only experienced drought conditions worse than this year about four times.
"For most states, the Palmer Drought Index, which goes back to 1895, ranks this drought among the top 10 or so years—so far," Call said.
It's That Darned Evaporation
Call said that even with a few good rainfalls, the intense heat and summer sun could shatter dreams of a quick recovery—and fall may be our earliest hope.
He said one of the reasons this drought has been so bad is because of the critical time it went from being a little worry to a big concern.
"One reason this drought came on suddenly was because not only was it dry, but it was very hot," Call said. "When it's very hot, there's a lot of evaporation and plants become stressed much more quickly because they are losing a lot more moisture to the air."
And, the drought seems to cause a lot more problems than just zapping moisture from plants—it can also create a cycle of dryness.
During the late summer, a lot of moisture in the air actually comes from crops, Call said. Without that moisture, it is more difficult for rainstorms to develop.
"The sun is very intense and it's very warm. Even if it starts raining a bit more, [the sun] will evaporate a lot of that moisture and it's not going to go into the ground as much as it would this fall," he said.
As fall temperatures arrive, Call expects the precipitation to go more quickly into the ground and accumulate more easily.
When Will It End?
Though he said predictability is very limited with droughts, Call estimates that if most states get an inch to two inches of rain a week for the next couple of months, things may start to look up by September.
But, he reminded, expectations for a changing weather pattern aren't high—a tropical system or sustained rainfall would be needed to change the drought trend. Call said neither is very likely, and estimated that most states need nine to 12 inches of rain to fully erase the effects of the drought.
Though the drought may continue into fall and winter, drought isn't as noticeable during those seasons. Consistent rains in the spring may be the best bet for a full recovery. Call said that if that happens, residual effects for next year's growing season could be minimal.
"If there are consistent rains in the spring, even if there is a deficit from the past, that should be sufficient for crops to grow," he said.
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