NWS issues 'Particularly Dangerous Situation' severe thunderstorm watch for central and eastern South Dakota

The National Weather Service’s Storm Prediction Center has issued a particularly dangerous situation severe thunderstorm watch for parts of central and eastern South Dakota, warning that a developing line of storms could bring widespread destructive winds through 11 p.m. CDT Saturday. The watch, Severe Thunderstorm Watch No. 513, was issued at 3:35 p.m. CDT by the Storm Prediction Center in Norman, Oklahoma. In the watch text, forecasters wrote, “...THIS IS A PARTICULARLY DANGEROUS SITUATION..."

The center said the main threat is extreme straight-line wind. Its watch text warned of “Widespread damaging winds and scattered significant gusts to 100 mph likely,” with isolated hail up to 1.5 inches in diameter also possible. Forecasters said thunderstorms were expected to strengthen during the afternoon, with an initial risk of isolated large hail and severe wind gusts before organizing into a linear cluster — essentially a squall line — over central and eastern South Dakota by early evening. In its forecast summary, the center said peak gusts of 85 to 100 mph are likely. The watch text also noted that severe thunderstorms can occasionally produce tornadoes, though tornadoes were not listed as the primary threat.

A watch does not mean severe weather is already happening everywhere in the outlined area. It means atmospheric conditions are favorable for severe thunderstorms to develop in and near the region covered by the watch, and that later warnings may be issued for specific communities if storms intensify or move in. As the Storm Prediction Center put it: “REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area.” Residents in central and eastern South Dakota were being urged to monitor forecasts and be ready to act if warnings are issued later Saturday.

The particularly dangerous situation, or PDS, label is uncommon in severe thunderstorm watches. The Storm Prediction Center uses it when forecasters believe an outbreak could produce especially significant, high-impact severe weather, including extreme wind events. That makes Saturday’s watch stand out even before any local warnings are posted.

Forecasters’ concern also comes against a backdrop of recent severe-wind weather in South Dakota. On June 29, a separate storm event in the state produced preliminary measured gusts as high as 131 mph near Highmore and Holabird, according to local National Weather Service summaries and regional reporting. That earlier event is not connected to Saturday’s storms, but it underscores why officials take setups capable of widespread extreme wind seriously.

As of about 3:42 p.m. CDT, the event was still unfolding, and no authoritative Storm Prediction Center storm-reports summary or National Weather Service damage survey had yet confirmed the forecast wind speeds or any resulting damage in the watch area.