* Light rain in US Southwest, more needed
* Crops expected to keep deterioration
* Soybeans have the best chance to recover
* Return to heat and dryness by next week
By Sam Nelson
CHICAGO, July 26 (Reuters) - Light showers overnight in the southwestern U.S. Midwest were too little too late to prevent further losses to corn and soybean yields, and next week will bring the return of high heat and drought, an agricultural meteorologist forecast Thursday.
Rain in the northern Midwest this week improved corn and soybean crop prospects, while heat and dryness in the southwestern section continued to stress crops, said Andy Karst, meteorologist for World Weather Inc.
"There should be some improvement in areas like the Dakotas and Minnesota. They have had some good rains of up to an inch or more, and there should be more rain and more improvement over the next week," Karst said.
Nebraska, Kansas, Missouri, Iowa and Illinois got some rains overnight, but they were too light to do much good. As a result, there will still be declining yields in those areas, Karst said, especially for corn.
"Corn is already brown so whatever yield has been established for corn that will be the final count," he said.
Karst said there had been forecasts for 1.5 to 3 inches in portions of the southwestern Midwest, but the rains were lighter than had been predicted.
There was generally a half inch or less, with locally heavier amounts, mainly in the north into Iowa of 1 to 1-1/2 inches. Heavier rainfall was very localized, he added.
"Shenandoah, Iowa got 1.5 inches, the biggest downpours were in the north into Iowa but they were pretty isolated," Karst said.
Karst said hot weather would continue in the southwest with highs in the 90s to low 100s degrees Fahrenheit, but more moderate temperatures in the 80s and low 90s would prevail elsewhere.
Commodity Weather Group (CWG) on Thursday said roughly two-thirds of the Midwest would get up to 0.50 inch of rain or more by Monday.
Thundershowers overnight in the southeast included at least a half inch of rain in 40 percent of Iowa and close to 25 percent of the Midwest overall.\
Scattered showers will extend eastward on Thursday into Illinois, Indiana and Ohio, with additional rain likely in the central and northwestern Midwest Saturday through Monday.
CWG said the rains would temporarily ease moisture stress, mainly aiding soybeans.
Hot and dry weather is expected to return to much of the southwestern Midwest by the middle of next week, according to CWG.
Reporting By Sam Nelson