After most of New Orleans sat submerged in water for weeks after Hurricane Katrina, the eight months since Oct. 1 have been the driest southern Louisiana has been during the 111 years that records have been kept, the state climatologist says.

Since October, most of the southern half of the state has averaged just 21 inches of rain, down from the usual 40-inch average, climatologist Barry Keim said. The National Weather Service says the rest of June promises more of the same.

"We're in what's called extreme drought," Keim said of the state's record-breaking dry spell. "We've really been suffering here, especially since Katrina."

Without the once-dependable daily showers, lawns have browned, rice and sugar cane crops are suffering and residents have emptied store shelves of hoses and other irrigation devices.

The increase in watering could stress city and parish pumping systems, and officials fear they could break because of ground subsidence caused by the lack of rain.

"A tropical storm would do wonders for us right now," Keim said. "A weak one, of course."

The forecast for rest of the month calls for little or no rain, said Mike Shields, senior forecaster at the National Weather Service office in Slidell. Shields said there will be a chance for only spotty showers over the weekend.

"And then until the end of the month, it looks like the same pattern of high pressure still over us and keeping us dry," he said.

Southern Louisiana had been abnormally dry for about five months before the storm made landfall Aug. 29., Keim said.

"The drought was interrupted, if you will, by Katrina, and we went back into the drought pattern. Then we got that deluge from Rita. And as soon as that storm left, we went right back into the drought pattern," he said.

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Normally, humidity rises into the sky, forming a cloud and then rain. But Keim said a stable structure of atmosphere is hanging over the region, preventing the moisture from rising, similar to the atmospheric conditions in normally arid states.

"For whatever reason, this dome of upper pressure in the atmosphere seems displaced east by a few hundred miles," Keim said.

The National Weather Service predicts that rain in the area will return to normal levels over the next three months. But Keim said such predictions typically can be way off.

"We're crossing our fingers," forecaster Tim Destri said. "We can't say for sure, but we see some hope of getting back to the typical summer pattern."