I happened to see a posting on an internet forum that the NWS Central Region was going to be changing the hail size criteria on Severe Thunderstorm Warnings from 3/4 inch to 1 inch. I have not seen anything to confirm this other than as an experiment involving the WFOs in Kansas. There was nothing either in the last spotter newsletter from WFO Des Moines or in their spotter information. Can anyone provide verification on this?

Yeah

At http://www.nbc15.com/newsyoucanuse/headlines/39617592.html

It explains it a bit.

I heard this as well during spotter training over the weekend. Not official but possible this spring

I'm going to try to make it to the class in Boone on Monday night. Sounds like something to keep in mind anyway.

Donna D. from DVN said its in the planning stages, but it could be active as early as April. She said the reason for the change was the fact that hail of smaller sizes than an inch usually is damage free... cept for the small dents on ones head... LOL. I had heard rumor of a change in the wind as well, but she squashed that rumor tonight. Winds remain at 58 MPH.

Dan,
I just got word, WFO's across Iowa and Illinois are officially changing to 1" inch hail beginning April 1st 2009. Spotters will still be requested to report hail of any size, but the criteria will be 1" hail instead of 3/4".

Thanks for the heads up.

NWS in Milwaukee is officially changing to 1" as well. The original date was scheduled for March 15th, but they thought they may delay it a bit as they got the Spotter Training schedules.

I am not sure, but I think just about all of the CRH offices are making the change. Dan, please confirm that for me.

According to the supplement to the 1" criterion experiment (#10-511) a rolling implementation will be used with all WFOs being involved by July 1, this policy will continue until "the supplement is rescinded or superseded by national policy."

The county warning areas of the following WFOs are included:
North Dakota: Bismarck, Eastern North Dakota(Grand Forks)
South Dakota: Rapid City, Aberdeen, Sioux Falls
Minnesota: Minneapolis (Chanhassen), Duluth
Wisconsin: La Crosse, Green Bay, Milwaukee (Sullivan)
Michigan: Marquette, North Central Lower Michigan (Gaylord), Grand Rapids, Detroit
Indiana: Northern Indiana (Webster), Indianapolis
Kentucky: Louisville, Paducah, Jackson
Illinois: Chicago, Central Illinois(Lincoln)
Iowa: Des Moines, Quad Cities (Davenport)
Missouri: Pleasant Hill, Springfield, St Louis, (plus two counties in WFO Memphis CWA)
Nebraska: North Platte, Omaha, Hastings
Kansas: Topeka, Wichita, Dodge City, Goodland
Colorado: Boulder/Denver, Pueblo, Grand Junction
Wyoming: Riverton, Cheyenne, (plus one county in WFO Billings CWA)

www.nws.noaa.gov/direc...06pend.pdf