The North Dakota Agricultural Weather Network began reporting rainfall data for the 2007 growing season on April 1.

NDAWN stopped reporting rainfall for the winter on Nov 1.

The NDAWN network consists of 70 automated weather stations installed strategically throughout North Dakota, western Minnesota and northern South Dakota to capture environmental variables at North Dakota's prime agricultural locations. The network records air temperature, solar radiation, precipitation, wind information, atmospheric pressure and soil temperature.

NDAWN uses automated tipping bucket rain gauges, which allow the network to report each tip during rainfall events in nearly real time. However during winter months, most snowfall accumulates on top of the rain gauge waiting to be melted.

""When the snow melts, the gauge records it, but at a different time period than when the precipitation actually fell,"" said Adnan Akyuz, NDAWN director. As a result, the tipping bucket rain gauges can report erroneous precipitation during the winter.

Thus, NDAWN adopted a policy of not reporting precipitation between Nov. 1 and April 1. Consistent beginning and ending dates allow the data manager to be able to omit winter precipitation amounts from the report more efficiently, according to Akyuz.

Snowfall before and after those dates also can cause reporting problems.

""Users should use the data with caution in an event of snowfall, which is still common in North Dakota in the spring and autumn,"" Akyuz said.

To access rainfall data or for more information about NDAWN, go to its Web site at http://ndawn.ndsu.nodak.edu/.

NDAWN began in 1989. Its operations team is housed in North Dakota State University's Department of Soil Science.

Agriculture Communication