Dunwoody, Georgia

To: subscribers: NWS partners... users and employees

Subject: National change in minimum hail size criterion
          for issuing Severe Thunderstorm Warning /svr/
          and severe weather statement /svs/ products
          effective January 5 2010

Effective Tuesday January 5 2010 at 0001 coordinated Universal time
/UTC/... all NWS weather forecast offices /wfos/ will operationally
change the minimum hail size criterion used to issue Severe
Thunderstorm Warning /svr/ and severe weather statement /svs/
products from 3/4 inch /penny/ diameter or larger hail to 1 inch
/quarter/ diameter or larger hail.

No change is being made to the svr and svs product wind criterion of
wind gusts equal to or in excess of 50 knots /58 mph/.

A public information statement /pns/ soliciting comments regarding
this change was issued September 13 2009 /use lowercase/:

   http://www.Weather.Gov/os/notification/pns09 1 inch hail.Txt

The NWS received 63 comments in response to the pns... 54 of which
/86 percent/ supported the change. A web Page has been created to
address the change... since some comments indicated a need
for additional outreach. This web Page is available at /use
lowercase/:

   http://www.Weather.Gov/oneinchhail/

The NWS reviewed all comments before deciding to change the minimum
hail size criterion for svr and svs products.

Central and western region wfos currently issue svr and svs products
experimentally using the 1 inch /quarter/ or larger diameter hail
size criterion /use lowercase/:

   http:/www.NWS.NOAA.Gov/om.Notification.Scn09-19hail change.Txt
and
   http:/www.NWS.NOAA.Gov/om.Notification.Scn09-36wr hail exp.Txt

These wfos will continue to issue 1 inch /quarter/ hail size
criterion products experimentally through January 4 2010. All NWS
wfos will adopt the new criterion operationally on January 5 2010.

For further information regarding this change... please contact:

    John T. Ferree
    fire and public weather services branch
    120 David l. Boren Blvd suite 2312
    Norman OK 73072
    405-325-2209
    John.T.Ferree@noaa.Gov

Or

    lans p. Rothfusz
    meteorologist in charge
    NWS Peachtree City GA
    4 Falcon drive
    Peachtree City GA 30269
    770-486-1133 x222
    lans.Rothfusz@noaa.Gov

National Weather Service change notices are online at /use
lowercase/:

    http://www.Weather.Gov/os/notif.Htm