* Snowstorm adds valuable soil moisture
* More moisture needed in drought-stricken Plains
* Another smaller storm to land by weekend
By Sam Nelson
CHICAGO, Feb 22 (Reuters) - Heavy snowfall and rain covered nearly all of the drought-stricken U.S. Plains hard red winter wheat region late this week, providing some relief from the worst drought in over a half century, an agricultural meteorologist said on Friday.
"It's going to help but it's not a fix, more is needed to bring the area out of drought," said Andy Karst, meteorologist for World Weather Inc.
Karst said the snowfall amounts were variable with up to a foot or more in the north or roughly 0.75 inch of moisture and another lighter event is headed for the area for the weekend.
"A weaker storm over the weekend will bring another 0.10 inch to 0.35 inch of moisture with a mix of rain and snow," he said. But "they will need a lot more to improve the drought."
Commodity Weather Group (CWG) on Friday said the next storm on Sunday and Monday would bring another 4.00 to 8.00 inches of snow from central Kansas into Iowa.
"Drier weather then returns, but these events will put a dent in drought conditions," said CWG meteorologist Joel Widenor.
Thursday's weekly Drought Monitor report issued by a group of state and federal climatologists showed 18.66 percent of the contiguous United States was suffering from extreme drought, up from the 17.71 percent a week earlier and the percent in exceptional drought, the worst category, grew to 6.66 percent, up from 6.61 percent the previous week.
Kansas wheat farmers welcomed the winter snowstorm but the drought-stress on the winter wheat crop from seeding time last fall until now probably has harmed some of the crop beyond repair, Karst and other crop experts have said.
Don Keeney, meteorologist for MDA EarthSat Weather, said that as of early February, roughly 4 inches to 6 inches of rain were needed in Kansas, the top producer of hard red winter wheat, to bring the state out of drought status. And up to 8 inches were needed in a pocket of severe dryness in northeastern Kansas, a big corn and grain sorghum growing area.
Similar amounts were needed in Nebraska, Texas, Oklahoma, Iowa and Missouri and the northern reaches of Illinois and Indiana.
Significant winter rainfall and snow has eliminated the drought for now in an area roughly from Illinois eastward, according to Keeney. (Additional reporting by Carey Gillam in Kansas City; Editing by Chizu Nomiyama)