| LSR | A Local Storm Report provides information about observed severe or significant weather events such as tornadoes, hail, heavy rainfall, damaging wind, etc. |
| PWO | The Public Severe Weather Outlook is prepared by the Storm Prediction Center for use by the media, emergency managers and the public when a significant severe weather episode is anticipated. It is usually issued up to 36 hours in advance of the expected event. |
| SAW | Preliminary notification of watch issuance and watch cancellation messages alert weather service offices that a watch is going to be issued/cancelled. |
| SEL | Severe Local Storm Watches (severe thunderstorm and tornado) are issued when conditions are favorable for the development of severe thunderstorms and/or tornadoes in or near the watch area. The watches are usually valid for about 6 hours. A Severe Thunderstorm Watch is issued when conditions are favorable for the development of severe thunderstorms in and near the watch area. A Tornado Watch is issued when conditions are favorable for the development of severe thunderstorms and tornadoes in and near the watch area. A Watch Cancellation Message (WW) is issued by the Storm Prediction Center when it cancels a watch. |
| SLS | Severe Local Storm Watch and Areal Outline (Redefining statement) is a rewording of the tornado or severe thunderstorm watch area for use by the media. |
| SWO | Severe Storm Outlook Narrative (SWODY1,SWODY2) specifies states or parts of states that are in areas where there is a slight, moderate or high risk of severe thunderstorms. The narratives issued daily and cover periods up to 52 hours in advance. SELS Mesoscale Discussion (SWOMCD) is issued on a routine/daily basis up to 6 hours in advance to communicate the current judgement of the Storm Prediction Center concerning severe weather potential. It can also be used to provide guidance on other mesoscale phenomena such as heavy snow potential, formation/dissipation of heavy fog, etc.) |
| SVR | A Severe Thunderstorm Warning is issued by local warning offices when a severe thunderstorm is occurring, is imminent or is suspected. |
| SVS | Severe Weather Statement is used to provide specific information on observed severe weather |
| TOR | A Tornado Warning issued by local warning offices when a tornado is occurring, is imminent or is suspected. |
| WWA | A Watch Status Report is issued periodically by the Storm Prediction Center while a watch is in effect to describe the current status of the severe weather situation and if the watch will expire or be reissued. |