* Dryness to affect crops, water transportation
* Cold snap also puts pressure on crop prospects
By Sam Nelson
Jan 15 (Reuters) - Forecasts for a return to dry weather for the balance of January in the already drought-stricken U.S. western Midwest and Plains are renewing worries among agriculture interests following the worst drought in more than 50 years in 2012.
"Dry weather will prevail in core drought areas of the western Midwest and Central Plains through the last half of January," said Joel Widenor, agricultural meteorologist for Commodity Weather Group. "This will also prevent any long-term stabilization in river levels in the middle Mississippi River Valley."
Heavy rainfall over the weekend in the southern Midwest provided much-needed soil moisture in some areas and also boosted river water levels, an agricultural meteorologist said on Tuesday.
However, the western Midwest and Plains States, areas where nearly all of the U.S. hard red winter wheat is grown, remained dry, and there are no forecasts for drought-relieving rain or snow soon.
Rainfall over the weekend was concentrated in the southern and southeast Midwest and helped boost river shipping prospects on the main U.S. waterway, the Mississippi River.
"It certainly was welcome and lifted the water level south of St. Louis," said Don Keeney, meteorologist for MDA EarthSat Weather. "The only problem now is it looks dry for about two weeks, so water levels will be receding again."
Two to four inches of rain, and up to five inches in some areas, were received over a broad area of the U.S. Delta and southern Midwest, he said.
Keeney said a cold snap this week may have caused some minor winterkill in areas of western Nebraska, and a blast of cold Arctic air is expected next week centered on the Midwest.
"It will drop to the single digits in the north, so this will need to be watched for some possible harm to some wheat," he said. The bitter cold will not reach into the U.S. Plains hard red winter wheat region, he added.
The U.S. Plains remained tightly gripped by a severe drought, according to a report issued last week by a consortium of federal and state climatology experts, and fears mounted that another hot, dry year could lie ahead for key crop-growing and cattle-grazing regions.
The government declared much of the central and southern U.S. Wheat Belt a natural disaster area last Wednesday due to persistent drought threatening the winter wheat harvest.
In its first disaster declaration of the new year, the Agriculture Department made growers in large portions of four major wheat-growing states - Kansas, Colorado, Oklahoma and Texas - eligible for low-interest emergency loans. (Reporting By Sam Nelson; editing by John Wallace)