* WHAT...For the Heat Advisory, heat index values up to 109 expected. For the Extreme Heat Warning, dangerously hot conditions with heat index values up to 113 expected.
* WHERE...Portions of west central Iowa and east central and northeast Nebraska.
* WHEN...For the Heat Advisory, until noon CDT Sunday. For the Extreme Heat Warning, from noon Sunday to 7 AM CDT Monday.
* IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. Hot temperatures and high humidity may cause heat illnesses.