(The original NOAA weather service page won't last very long, so the page has been Saved to the Stormdancer Archives. I suspect someone's gonna be in trouble for this one...)
Update [10:35]: Awww, it's already gone, less than 45 minutes after I spotted it. Wuff got it from FARK, so the NOAA people probably noticed that they were getting bombarded with hits for a little out-of-the-way town in Missouri and found the gag. Check the Archive Link, kids, it's still good.
Oh, and there really is a Hazardous Weather Condition moving into that area, so they needed to scrub the gag to let people know the real thing.
I stand by my original hypothesis: Somebody's Gonna Get In Trouble.
Update [11:02]: At The Missouri: All Warnings NOAA page, I found this:
WWUS73 KEAX 171825 NPWEAX URGENT - WEATHER MESSAGE NATIONAL WEATHER SERVICE KANSAS CITY-PLEASANT HILL MO 1225 PM CST WED DEC 17 2003 MOZ012-021-171930- ANDREW MO-CLINTON MO- 1225 PM CST WED DEC 17 2003 ...THE TEST EXCESSIVE HEAT WATCH IS CANCELLED... PLEASE DISREGARD THE PREVIOUS NPWEAX MESSAGE. IT WAS A TEST MESSAGE. $$ NOONAN
Someone REALLY has a sense of humor...