Sunday PDS severe thunderstorm watch for Northern Plains warns of 100 mph gusts

The National Weather Service’s Storm Prediction Center issued a Particularly Dangerous Situation severe thunderstorm watch Sunday afternoon for parts of four Northern Plains states, warning that widespread damaging winds with localized gusts up to 100 mph could develop through 10 p.m. MDT. Large hail and a possible tornado or two were also listed among the threats.

Severe Thunderstorm Watch No. 285 was issued at 2:55 p.m. MDT Sunday and covers southeastern and eastern Montana, western and central North Dakota, western and northwestern South Dakota, and northeastern Wyoming. The watch remains in effect until 10 p.m. MDT Sunday, covering the late afternoon and evening period when forecasters expected storms to intensify.

What makes this watch stand out is the label attached to it: PDS, short for Particularly Dangerous Situation. The Storm Prediction Center uses that wording sparingly, reserving it for relatively rare, high-end setups. In this case, forecasters signaled an unusually serious wind event, writing in the watch text, “...THIS IS A PARTICULARLY DANGEROUS SITUATION...” and warning that “widespread damaging winds and scattered significant gusts to 100 mph” were likely. In SPC terminology, “significant” severe wind means 75 mph or higher, so the forecast in this watch is well above the usual severe threshold.

The agency said severe thunderstorms were expected to develop Sunday afternoon and strengthen first in the western part of the watch area. An initial storm cluster was then forecast to organize into a bow echo — a curved line of intense thunderstorms often associated with destructive straight-line winds — as it moved into the western Dakotas during the evening. That evolution, the SPC said, would likely increase the severe wind threat, with 80 to 100 mph gusts possible in localized swaths.

Other hazards listed in the watch included scattered large hail, with isolated stones up to 2 inches in diameter possible, and a tornado or two. The watch text also flagged aviation dangers including extreme turbulence, hail to 2 inches and surface wind gusts to 85 knots.

A severe thunderstorm watch does not mean severe weather is already happening everywhere in the watch area. It means conditions are favorable for severe thunderstorms in and near the region covered by the watch. As the SPC noted, “REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area.” Residents should monitor local National Weather Service forecasts and any storm-specific warnings that may be issued.

At the time reflected in the source material, the Storm Prediction Center had not yet posted a status report for Watch 285, and no verified storm-impact reports were included.