Winter Weather — Washington Palouse, Washington

2013-12-02 · Washington Palouse, Washington

Event narrative

Slushy snow accumulations and excessive speed were responsible for a two car accident along Highway 270, seven miles east of Pullman. One driver was killed and the other was injured with the driver in the westbound lane loss control and crossed into the eastbound lane. The time of the accident was 1605 PST.

Wider weather episode

A strong winter storm impacted the Inland Northwest in two phases. During the first phase, a deep trough of low pressure dropped southward from British Columbia into the region. Ahead of the trough, a warm moist conveyor belt of subtropical moisture delivered a shield of isentropically driven precipitation. Snow levels were driven upward rising above 3000 feet during the first phase of the storm. The second phase of the storm occurred on December 2nd as the trough sagged into Eastern Washington. Snow levels fell to valley floors and numerous convective snow showers developed and pivoted around a nearly stationary 700 millibar low. A majority of the lowland snow came with the second phase of the storm.

Source: NOAA Storm Events Database, event_id 482254. Narrative written by the NWS forecast office that issued the report.