The National Weather Service says a brief tornado touchdown was reported east of Becker Saturday afternoon. Another tornado was reported a few minutes later near Big Lake. The weather service has issued a tornado warning for southeastern Sherburne, southern Isanti and northern Anoka counties until 3:15 p.m. Saturday. Twenty-five counties in Minnesota and six in Wisconsin are covered by a tornado watch issued Saturday afternoon and lasting until 10 p.m. Saturday night. The watch covers central and southern parts of Minnesota and northwestern Wisconsin.