Apex domains cannot have CNAME records.
Question and response
Question
dig tornadooklahoma.com. NS
Answer
tornadooklahoma.com. 5 NS ns-384.awsdns-48.com.
tornadooklahoma.com. 5 NS ns-753.awsdns-30.net.
tornadooklahoma.com. 5 NS ns-594.awsdns-10.net.
tornadooklahoma.com. 5 NS ns-1402.awsdns-47.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0