NWS Jackson, MS Product Guide--Severe Weather Products

A Tornado Watch means that conditions are favorable for the formation of tornadoes and severe thunderstorms in and close to the watch area. Watches usually last around 6 hours and can cover areas of about 25,000 square miles(many counties). The Storm Prediction Center in Norman, OK coordinates with the local NWS Weather Forecast Office to issue the watches, and the local office can expand the watch if the potential for hazardous weather looks to continue into additional counties or cancels the watch when the threat for severe weather has ended. 

PDS (Particularly Dangerous Situation) Tornado Watch is an enhanced Tornado Watch when conditions are favorable for thunderstorms producing destructive tornadoes. Hail and strong winds are also possible. Typically, this is issued when there is a likelihood of multiple strong (damage of EF2 or EF3) or violent (damage of EF4 or EF5) tornadoes. Note: "PDS" does not appear in the watch headline, but as a special line within the initial watch product.

The local NWS office issues a county list of counties included in each watch.  See "Watch County Notification" below.

A Tornado Warning is issued when a tornado is detected on radar or a reliable report of a tornado is received.  Persons in the warning area should take immediate action to protect their lives and the lives of others.  Warnings are issued by based on the path of a particular storm, and are listed by county or parts of the county. Warnings usually last for less than one hour, but a particular location may be under multiple warnings during a severe weather event. 

A Tornado Emergency is an enhanced Tornado Warning that will be issued by NWS Jackson when there is a heightened risk for a killer or violent tornado of EF3 rating or greater. In these very rare cases, we have to be very confident that extreme danger exists to the public based on: a) radar showing strong indications of a strong/violent tornado, b) reliable reports of significant damage or spotters reporting a large tornado, c) environmental conditions supporting violent tornadoes, especially when a Particularly Dangerous Tornado Watch is in effect. In most cases, the Tornado Emergency will be instituted after an initial Tornado Warning is already in effect. 

A Severe Thunderstorm Watch means that conditions are favorable for the formation of severe thunderstorms in and close to the watch area.  Severe thunderstorms produce winds in excess of 58 mph (50 knots) and/or hail 1 inch (quarter size) or larger. Watches usually last around 6 hours and can cover areas of about 25,000 square miles(many counties). The Storm Prediction Center in Norman, OK coordinates with the local NWS Weather Forecast Office to issue the watches, and the local office can expand the watch if the potential for hazardous weather looks to continue into additional counties or cancels the watch when the threat for severe weather has ended. 

A particularly dangerous situation (PDS) severe thunderstorm watch may be issued when conditions are favorable for thunderstorms containing 1 inch or larger hail and/or wind gusts of at least 80 mph (64 knots). Typically issued for widespread, significant non-tornadic severe weather events. Note: "PDS" does not appear in the watch headline, but as a special line within the initial watch product.

The local NWS office issues a county list of counties included in each watch.  See "Watch County Notification " below