ST. LOUIS (AP) -- Growers in key farm states punished by the nation's worst drought in two generations welcomed recent rains that at least for a time soaked their parched crops and eased the dryness. But with Hurricane Isaac's remnants crawling their way, some farmers wonder whether too much relief is on the horizon.

Forecasters expect Isaac, which since making landfall Monday on the Gulf Coast has been downgraded to a tropical storm, could slide into Missouri, Illinois, Indiana, Iowa and Ohio as early as Friday, dumping as much as 12 inches of rain on the region.

That kind of deluge -- usually welcomed by farmers who are famously at nature's mercy -- may be too little too late for corn growers and could actually work against them by making their fields too muddy to accommodate harvesting equipment. Strong winds could topple drought-weakened stalks.

"I don't want the wind," said Kenneth Metcalf, a 75-year-old farmer with nearly 600 acres of corn and 120 of soybeans yet to harvest near Mechanicsburg, central Illinois. "This corn is not at all that stable to start with, and we don't need 50- or 60-mile-per-hour winds. It would just break the stalks off."

Portions of the thirsty Corn Belt that got a good soaking last weekend saw the extent of their drought conditions level off or slightly improve, according to a drought-tracking effort.

The weekly U.S. Drought Monitor map released Thursday shows that the section of the continental U.S. in the worst two categories of drought -- extreme and exceptional -- remained relatively unchanged at 23.2 percent as of Tuesday.

But thanks to rains last weekend, the amount of Iowa -- the nation's biggest producer of corn -- in the two worst drought classifications fell by 9 percentage points to 58.3 percent. Illinois saw a 7 percentage point drop-off to 69.6 percent as Kansas' numbers slid 6 points to 90.1 percent. Missouri's status improved nominally, slipping nearly 2 percentage points to 97.4 percent. Indiana's portion in the two highest drought conditions rose, up 2.1 percentage points to 39.22 percent.

Still, the rains may not be enough to help corn growers.

The U.S. Department of Agriculture reported Monday that 52 percent of that crop was listed as being in very poor or poor shape, more than double the status of 19 percent in those two categories at this time last year. Soybeans, which could benefit from more rains because it's earlier in the growing season than corn, were faring only slightly better, with 17 percent of that crop described as being very poor while an additional 21 percent was poor, the USDA said. A year ago, just 15 percent of the nation's soybeans were in those categories.

The USDA said that just 6 percent of the nation's corn harvest was completed as of Monday, three times the average at this time of year over the previous four growing seasons.