Figure 1. Precipitation from April 13 to April 19. (Source: High Plains Regional Climate Center)	Figure 2. Departure from normal precipitation from Oct. 1, 2010 to April 19, 2011.  Areas in yellow-red are below normal.  (Source: High Plains Regional Climate Center)

April 22, 2011

The April 15-16 storm that swept through Nebraska provided the most significant, widespread moisture event in over six months (Figure 1). A combination of rain, thunderstorms, snow, and blizzard conditions were reported. Winter conditions were observed across the northern half of the state, with liquid moisture across southern Nebraska.

Another round of moisture occurred April 18 through midday April 19, with liquid equivalent totals ranging from 0.50 to 1.25 inches east of the Panhandle. Accumulating snowfall once again was reported across north central and northeast Nebraska. Total accumulations between the two events exceeded four inches across sections of central and south central Nebraska. (See rainfall totals for April 15-19 from NeRAIN.)

Even with these rains, much of the state is still below normal precipitation for the recharge period from Oct. 1, 2010 to April 19, 2011 (Figure 2).

After upgrading parts of southwest, central, and south central Nebraska to moderate drought conditions two weeks ago, the recent moisture has caused U.S. Drought Monitor authors to temporarily remove any drought designations for Nebraska (Figure 4). Precipitation deficits from October 1 have been reduced substantially in the past week, but are still greater than three inches in areas of southeast and east central Nebraska (Figure 2).  This is the primary reason why abnormally dry conditions are still depicted for much of the southern half of the state (Figures 3 and 4).

The extended forecast shows additional chances for moisture to cross the state on a 24-36 hour interval at least through April 26. If the models are correct, a drier pattern may develop April 28 to May 4 and temperatures should return to near normal readings. East of Nebraska, rain and severe weather should continue to inhibit corn planting.

Nebraska currently is sandwiched between abnormally cold weather to our north and warmer weather to our south. Wheat has reached the heading stage in south central Kansas, while it is jointing in southern Nebraska. Spring wheat planting is non-existent across North Dakota as snow, below normal temperatures, and saturated soils are keeping producers out of the field.

The rain and cold air that overtook the northern Plains this past week might be a blessing in disguise as it has temporarily halted planting activities. Corn planting last year proceeded at a record pace in Nebraska, only to be followed by freezing conditions the first week of May. Although May freezes can’t be ruled out this year, delayed planting due to the recent cold snap makes it likely that this year’s corn would require a mid-May or later freeze to sustain damage to growing points.

Al Dutcher
Extension State Climatologist, Lincoln