Weather News: Tornado warnings delayed for public amid deadly weekend outbreak


Even as meteorologists, we rely on apps and notifications to warn us of danger.

Unfortunately, this weekend, those notifications were delayed.

As deadly tornadoes ripped through the state of Iowa on Saturday, endangered residents had no idea their warnings had been delayed.

The National Weather Service (NWS) warning system had technical problems sending warnings to the public, so the NWS office in Des Moines had to scramble to warn the public of tornadoes.

Deadly tornadoes, glitch in the warning system

The severe outbreak was in some ways unusual for the Des Moines area. It’s a state that typically gets tornadoes, but those rated as high as an EF-4 in March are the unusual part.

“We’ve only had in the history of the state, I believe, one EF-4 tornado in March and two or three EF-3s,” noted NWS Des Moines office meteorologist Jim Lee. “So it’s happened before. But it’s unusual to have them this strong so soon.”

Currently, the region has preliminary reports of six tornadoes in the state of Iowa.

The number could rise as meteorologists travel to the scene and inspect the damage.

One of the tornadoes would be an EF-0, two of them would be EF-1s, two EF-2s and the fifth a possible EF-3. The sixth tornado was an EF-4 that traveled 69.5 miles and was at times 800 meters wide according to the NWS.

In total, there were about 40 reports of tornadoes Saturday, mostly in Iowa.

This was all happening as the NWS encountered a technology glitch, affecting its warning system, sometimes causing a delay of almost 10 minutes for some warnings to be issued.

“Any delay in receiving tornado warnings is a serious matter because seconds count with a fast, violent tornado,” said Daryl Herzmann, a system analyst at Iowa State University.

He watched what was happening in real time and actively tweeted about the ordeal.

“When the local NWS office issues a tornado warning, that warning text must travel over a network to a central clearinghouse within the NWS in DC/College Park, MD for subsequent broadcast to the world,” Herzmann explained in an email to CNN. . “This network transmission to the central clearinghouse was suffering from this 3 to 10 minute latency due to a misconfigured network path, affecting nearly every NWS forecast desk.”

He was able to detect the differences by comparing the timestamps in the NWS text and when the product was actually received on his processing software.

According to a statement from the National Weather Service, the Des Moines forecast office was aware of the delay and took the precaution of issuing warnings earlier than they normally would have done under similar circumstances to compensate and save time. ensuring that warnings reached the public in a timely manner.

Their main source of alerts being insufficient, they had to compensate with any other type of communication.

“We used our helpline systems to send out advisories, phone calls and webinars with our partners. We are still engaging the public on social media. We have real-time chat to talk to the media,” pointed out Lee. “We have experts and backup systems so we can make sure we get the best quality warnings.”

The NWS noted that the NOAA Weather Radio and Emergency Alert System was activated and issued the warnings immediately, without delay.

They were still able to give about 20 minutes of time on average for people to get to safety which is impressive.

“I can confirm that the warning time averaged 20 minutes and some of the warnings were delayed in their release,” Susan Buchanan, director of public affairs for the weather service, told CNN Monday morning.

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Most broadcast weather forecasters use the instant messaging-style website to get first-hand warnings from NWS offices and then relay them to the public.

But people who relied solely on their cellphones to alert them were getting the message late due to NWS network latency, including the EF-4 wedge tornado heading directly for the town of Winterset.

A storm chaser captured footage of the tornado that hit Winterset, Iowa over the weekend.

“Yes, these delays have affected warnings for the Madison County tornado(es),” Herzmann said. “I don’t know if there’s a case where someone didn’t act because they didn’t get a delayed warning.”

According to an NWS update Monday afternoon: “The communications delay stems from a damaged fiber optic cable that serves our Dallas-Ft. Worth forecast office. The cable outage caused this office to switch from its primary terrestrial communications network to a backup satellite network that serves each NWS field office The increased number of messages flowing to the central message handler from offices in the NWS Central Region due to extreme weather conditions , combined with the performance characteristics of the satellite network used at a co-located site, slowed the queue of message transmissions and created a brief backlog in several offices.

“NWS systems engineers monitoring the networks worked to quickly trace the backlog to the Dallas-Ft. Worth office and when that office was removed from the network, warnings began to flow without delay. The office was kept offline until its mainnet is fixed.”

Read some of the other ways to get warnings other than your cell phone.

“Our primary focus now is to implement procedural changes immediately to avoid a repeat. A short-term option being considered would be to switch to the use of a back-up service by another forecast office in this type of situation, rather as satellite rescue, to prevent the accumulation of messages,” the statement said.

Herzmann said, “The NWS is plagued with computer-related crashes and outages during high-impact weather events. This particular type of latency issue has only happened once before, during of Hurricane Ida”.

Tornadoes one day, snow the next

Behind the storms this weekend, snow has begun to fall in the same areas destroyed by the tornadoes.

In fact, three to six inches fell, making cleanup and recovery efforts difficult.

“Today we’re going to have temperatures in the high 20s to 30s all day,” Lee noted. “Tuesday will see most highs in the 40s, but later this week it will get even colder. Thursday and Friday we’re probably looking at highs in the 20s.”

For much of the country over the weekend, spring was in the air.

Since it’s technically spring (according to weather forecasters), that made sense.

But now we are back to winter this week for much of the country as temperatures drop.

How cold will it be in your city this week?

There is a powerful storm system that can bring flooding and more severe storms to much of the eastern half of the country.

Nearly 50 million people are in a Level 2 out of 5 severe storm risk level today, including places like Philadelphia, Baltimore, Washington and Atlanta.

The main threat will be damaging winds, but a few tornadoes cannot be ruled out.

  • Follow the storms here.
  • Read the latest news on the storm threat.

Nearly 12 million people are now under flood watch in the Ohio Valley.

Additional precipitation will fall on already saturated places today, which could lead to flooding in places like Louisville, Cincinnati and Columbus.

Behind the front, a blast of arctic air will send temperatures nosediving.

“Washington, DC set a record 78 yesterday and will easily set another record today, topping 80,” CNN meteorologist Dave Hennen reported. “The strong cold front will drop temperatures by nearly 40 degrees with highs by Wednesday only in the mid-40s in the nation’s capital.”

The same theme will be true for much of the east, as temperatures drop dramatically behind the front.

Then a second push of cold air will set in by the end of the week.


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