About that "P-D-S" Weather Abbreviation

     If you have not heard a forecast including the abbreviation P-D-S....standing for Particularly Dangerous Situation...there's a good reason: It is only rarely used by the National Weather service.
     It is not something a TV forecaster made up...it's part of the official National Weather Service lexicon. 

     The NWS used it today for the storms rolling across Alabama tonight. 
     Though as I write this post just before 10:00 PM, the storms are yet to hit Montgomery, West and North Alabama have been hammered.

Here's the Wikipedia explanation for the use of PDS:  

The short history of the origin of the option of issuing a tornado watch with the enhanced Particularly Dangerous Situation (PDS) wording occurred during the winter of 1981-82 when the Severe Local Storms (SELS) unit transitioned to a more flexible method of issuing weather products. Ed Ferguson, Deputy Director of the National Severe Storms Forecast Center (NSSFC), suggested to Lead Forecaster Jack Hales that the guidance center could provide an opportunity to give more resolution to the tornado watch product. Hales suggested the PDS option to identify areas where, a few times each year, conditions are most likely to aid in the development of large and intense tornadoes. The first PDS tornado watch was issued by Robert H. Johns for the April 2, 1982 tornado outbreak across the southern and central Great Plains.^[4]