As an outbreak of severe weather moved through the central part of the United States overnight into Tuesday, a key part of the nation’s weather tracking system experienced an outage, potentially affecting forecasters’ ability to warn people of dangerous weather.

Radar data sites for the National Weather Service experienced “an intermittent network outage” over the course of four hours, according to Michael Musher, a meteorologist and spokesman for the service. “During this outage,” he said, “some warning services were impacted.”

Preliminary storm reports compiled by the Weather Service’s Storm Prediction Center suggested hail and winds had swept through the center of the country on Monday night into Tuesday. Tornadoes were reported in Oklahoma.

In Pueblo, Colo., the network went down at about 11:40 p.m. local time, said Makoto Moore, a meteorologist there. The National Weather Service in Boulder, Colo., covered Pueblo’s duties until the network was restored at about 3 a.m., said Mr. Moore, adding that he couldn’t remember the last time something similar had happened.

“That was basically it,” he said. “We were fortunate enough that we did not have any severe weather.”

By 6:30 a.m. Eastern time on Tuesday, service had returned to normal, Mr. Musher said. “Our Weather Service IT team mitigated the issue by moving network services from our data center in College Park, Md., to Boulder, Colo.”

“We’re working with the vendor right now to identify the root cause of the outage,” he added.

Such an outage is “very, very rare,” said Mark Taylor, a weather technology consultant, but could be dangerous during extreme weather. “During severe outbreaks, things can develop very quickly. Time is of the essence when it comes to alerting, especially for tornadoes,” he added.

This is a developing story.