It’s really important that anyone who is in charge of the safety of an institution — a university campus, for example — maintain an updated, working knowledge of how weather warnings work. Tweets sent today by Indiana University today could lead one to believe that its campus safety staff could benefit from some education in that area.
At 1:19 p.m. EST, the Indianapolis office of the National Weather Service (NWS) issued a tornado warning that included a portion of southern Monroe County, Indiana. The warning came with a polygon that clearly showed that the IU campus was not included.
Polygon associated with Nov. 5 tornado warning near Bloomington, IN. The National Weather Service issued the warning only for the area inside the red polygon.
In addition, the text of the warning indicated that “a severe thunderstorm capable of producing a tornado was located 12 miles northwest of Bedford, moving east at 30 mph.” In other words, the storm was not moving toward Bloomington or the IU campus (which is why NWS meteorologists drew the polygon as they did).
Six minutes after the NWS issued the warning, IU sent a tweet at 1:25 regarding what it called a “tornado warning for Bloomington.”
Update: National Weather Service has issued a Tornado Warning for Bloomington. Seek shelter immediately. Avoid windows and doors.
There is no tornado warning for Bloomington. The possible tornado is 12 miles south of town, and moving east. No tornado threat to campus. https://t.co/LDpHQed8nT
Dr. Kirkpatrick knew what he was talking about. Those sending tweets on behalf of IU demonstrated ignorance of the National Weather Service’s “storm-based warning” system. When the NWS implemented that system a decade ago, it replaced the county-wide warnings to which IU’s tweet refers, with warnings based on polygons that indicate where the actual risk is.
In subsequent tweets, Dr. Kirkpatrick attempted to point that out, as well as the fact that IU’s original tweet was ambiguous. IU’s response:
We act based on information from the emergency alert system. Better safe than sorry.
But is warning people who are not at risk really better than warning only people who are truly at risk? Is doing so truly “safe,” or does it exacerbate existing challenges with getting people to respond appropriately to warnings?
The people at any institution like IU, who are in charge of disseminating public safety information, would do well to take full advantage of the informational resources that exist among their own faculty. Doing so could lead to better weather safety communications in the future.
I was surprised and honored that this blog was chosen by the northern Indiana office of the National Weather as a 2017 Weather-Ready Nation Ambassador of Excellence.
If your organization is interested in helping the National Weather Service spread important weather safety messages, check out the WRN Ambassador program.
Blogger’s note: Below is an article I submitted to the “The Waynedale News,” a neighborhood newspaper in Fort Wayne, Indiana. If refers to the installation of an outdoor warning siren in a neighborhood that had been without one for years. The newspaper published the article July 7, 2017.
The new outdoor warning siren that’s coming to Waynedale brings with it some true risks that area residents might not have considered. Chief among those risks are over reliance and desensitization. Continue reading →
Today is the fifth anniversary of a “derecho” thunderstorm that did widespread damage in northern Indiana and locations to the southeast.
“At the peak of the event,” writes the northern Indiana office of the National Weather Service, “the Fort Wayne International Airport observing equipment observed a peak wind gust of 91 mph.”
“Winds were as strong as an EF-1 tornado over a widespread area,” the NWS web page continues, “which resulted in immense damage along the storm’s entire path.” (Emphasis added by W9LW.)
One of the best lessons of that storm should be that we can have massive damage without a tornado. This was a particularly dangerous severe thunderstorm, but there’s no such thing as a “particularly dangerous situation” thunderstorm warning, so we need to pay attention to all severe thunderstorm warnings, even though such warnings are not uncommon.
College of DuPage meteorology professor Dr. Paul Sirvatka presents at the DuPage County Severe Weather Seminar, March 11, 2017
The title of this post is one of the main points of a presentation I heard at the DuPage County (Ill.) Severe Weather Seminar March 11. College of DuPage meteorology professor Paul Sirvatka reminded spotters that the key to spotting a tornado in a classic supercell is knowing where the updraft is. As Dr. Sirvatka put it, a tornado is a “big sucky thing” that forms under an updraft.
Unfortunately, updrafts are not always easy to find. Depending on your location, important storm features can be obscured, making spotting difficult. And the closer you get to a storm, the more difficult it becomes to identify the important features.
It’s hard to protect yourself and your family from tornados, damaging straight-line severe thunderstorm winds, or large hail, if you don’t know that the National Weather Service has issued a tornado or severe thunderstorm warning for your location.
So, here’s my list of the best ways to get tornado, severe thunderstorm and flash flood warnings.
For 11 years, Alabama broadcast meteorologist James Spann (ABC 33/40, Birmingham) and several of his friends in the weather enterprise have produced a weekly podcast (internet talk show) called WeatherBrains. It was the first in what has become a group of weather-related podcasts that are jointly celebrating the first-annual National Weather Podcast Month in March.
The weather brains normally record WeatherBrains on Monday evenings. Audience members can watch the discussion live on YouTube, watch it later on YouTube or download the program as an audio recording for listening at their convenience.
W9LW’s Ramblings had chance to talk to Spann about the show that started the weather podcast genre and now has an audience in the tens of thousands. Watch the 14-minute interview on YouTube or read it below. The transcript includes a few helpful notes and hyperlinks.
W9LW’s Ramblings: What prompted you to get into the podcast business?Continue reading →
Widely shared snowfall forecast map from the European numerical weather prediction model run on Dec. 16, 2013 for the forecast period Dec. 22-23. What actually happened Dec. 22 and 23 wasn’t even close to this!
Winter weather is just around the corner in Indiana, which means so are authentic-looking but bogus long-range snowstorm forecasts on social media.
It won’t be long before we see claims that a storm a week or more away will bring huge snow accumulations. Many will have official-looking forecast maps, like the one above (which turned out to be wrong, by the way).
But these posts won’t be the work of professional meteorologists. Many will be the creations of school kids, passing themselves off as weather experts.
This is Winter Weather Preparedness Week in Indiana, so it seems like a good time to prepare readers for the ominous-looking but unreliable snow forecasts they’ll soon see.
To understand what amateur weather enthusiasts put on social media, it helps to know something about the computer programs that professional meteorologists use to guide their forecasts. These programs are called numerical weather prediction models. They simulate Earth’s atmosphere by describing it in a complex series of very complicated mathematical formulas.
The programs built on these formulas run several times a day on supercomputers around the world. Much of the output of these programs is available on the Web, in both numeric and graphical form.
The output of computerized atmosphere models is inherently inaccurate for several reasons, including:
It’s not yet possible to completely describe our chaotic atmosphere in mathematical equations and
The programs don’t have access to enough data about what our atmosphere is doing at the time they run (e.g. what the temperature, wind speed and wind direction are 10,000 feet over any given part of the planet).
Nonetheless, these programs kick out predictions of what the weather might be at any location at any time, as far in the future as 16 days, despite that fact that no computer or human can reliably forecast the weather that far in advance.
Now, imagine a young weather enthusiast who craves attention and loves snowstorms (because they get him out of school). When he sees an indication of heavy accumulations in the output of a single computer model, he might paste that model’s map into a Facebook post in which he writes a dire forecast of impending doom. Such an amateur forecaster might not be aware of (or care about) the model limitations described above. But she’ll love all the “likes” and shares her post receives!
So how do I know what to believe? First, I’m automatically suspicious of any social media post that forecasts specific snowfall amounts more than a couple days in advance. Second, I ignore any forecast that doesn’t come directly from professional sources I trust, such as:
For some time, I’ve looked at amateur storm chasers with some disdain. I believed that too many were putting themselves into too much danger, just to see, photograph and/or video record tornados. I doubted that many chasers were truly motivated by improving public safety and even fewer were doing real science, no matter what they said. I was concerned that many chasers set poor examples for the general public and that their “antics” encouraged lesser informed people to take uneducated and unwise risks.
I’ve been a SKYWARN storm spotter for more than a quarter century. When talking to friends, family members and even journalists about my volunteer service to the National Weather Service (NWS), I was careful to make sure they understood that I’m not a chaser, like the people they’ve seen on TV or on the Web. My ultimate goal, I’d explain, isn’t to see tornadoes, it’s to help protect my community from possible storms by staying close to home and relaying valuable information to the NWS.
So it was with some trepidation that I attended an event in November, 2015 called INChaserCon, a one-day convention in the Indianapolis area for storm chasers. I’m glad I went. Some of the people I met there changed my thinking. They are admittedly driven by a desire to see tornadoes. But my experience with them demonstrated that they’re also very passionate about getting reports to the NWS.
After the chasers learned that I have access to NWSChat – a private, internet-based text chatroom run by the NWS – they invited me to join them on Zello, a smartphone app with which they communicate with each other—so I could relay their reports to the NWS via NWSChat.
That’s exactly what happened during the August, 2016 tornado outbreak in Indiana and Ohio. As a tornadic storm moved east from Kokomo into the county warning area of my local NWS office, storm chasers John Tinney, Eric Lawson and David Buell reported wall clouds, funnel clouds, etc. via Zello. I relayed those reports via NWSChat.
Then, a storm over my own home in Fort Wayne, Indiana received a tornado warning. Storm chaser Michael Enfield immediately headed toward that storm. Via Zello, he promptly reported a wall cloud, then funnel clouds and then a tornado for me to relay via NWSChat. The NWS survey report recorded the time of the tornado’s initial touchdown as 5:27 p.m. – the same time as Enfield’s report, confirming that he saw and reported the tornado when it first touched down. That storm eventually did EF-3 damage to a rural part of Allen County, Indiana.
Throughout the event, any time the chasers had something to report, if I wasn’t immediately available on Zello, they’d keep trying until I acknowledged their reports. Getting reports through to the NWS was clearly very important to them. By the end of the event, I had typed 50 reports into NWSchat. All but about 15 of those came from storm chasers on Zello. The rest came from storm spotters via ham radio.
By aggressively chasing storms, my new friends put themselves in positions to immediately report weather that was not near any traditional SKYWARN spotters at the time. By religiously reporting, they played significant roles in protecting people in the paths of the storms.
A Facebook post by Lawson sums up pretty well how this particular group of storm chasers sees things:
“I noticed a developing supercell heading towards Kokomo was looking really strong and rushed out the door. By the time I was on interstate 69 southbound the strong EF3 was already in progress and heading towards the town in which I have spent many days of my youth, and is home to many great friends and their families. Hearing reports of the devastation in progress on the radio made my heart sink. I was rushing south in horror wondering if anyone I knew had been hurt. This is the moment that things really changed for me, I felt less excited about seeing tornadoes, and much more concerned with providing accurate information to keep people informed.”
I have no doubt there are other storm chasers out there who rarely report their observations to the NWS. There are likely some that don’t care about anything but the excitement of seeing a tornado.
But I’m convinced that the storm chasers I know are not among these. They’ve changed my attitude about chasers.
Tornado damage in northeastern Allen County Indiana. NWS photo.
When the National Weather Service issued a tornado warning for northeastern Allen County, Indiana at 5:14 p.m. Aug. 24, 2016, more people in the county got their initial alerts from mobile phones than any other information source, according to an informal, online survey conducted by the publisher of this blog.
Of people who indicated they were anywhere in Allen County at the time of the warning, slightly more than 32 percent said they first learned of the warning via their mobile phones (including “Wireless Emergency Alerts,” alerts from apps, text messages, social media, etc.). Television was the second-most-frequently cited initial warning source, at nearly 21 percent. Outdoor warning sirens, commonly referred to as “tornado sirens,” came in third, at 17 percent. Just under eight percent of respondents credited NOAA Weather Radio as their initial warning source.
Methods by which respondents indicated they first learned of the tornado warning. With this and all images in this blog, clicking the image will display a larger, clearer version.
The warned storm created a tornado in northeastern Allen County at approximately 5:27, according to a report from the northern Indiana weather forecast office of the National Weather Service. That was about 13 minutes after the NWS issued the warning. The tornado stayed on the ground until approximately 5:39, cutting a five-and-a-quarter-mile path to the northeast and doing damage consistent with the EF-3 rating on the enhanced Fujita scale.
Warned immediately
Nearly 62 percent of the survey’s 167 respondents indicated that they received the warning “immediately.” Another 19 percent said they received the warning with 10 minutes of its issuance, which would still have been a few minutes before the tornado touched down. Nearly 20 percent of respondents did not learn of the warning any sooner than 30 minutes after the NWS issued it, well after the tornado had lifted.
Above: how soon people reported learning of the tornado warning.
The red, five-sided polygon encloses the part of Allen County to which the tornado warning applied. The dark yellow line within the polygon depicts the tornado’s path.
The NWS drew a five-sided polygon that enclosed 144 square miles to indicate the portion of northeastern Allen County to which the tornado warning applied. As a whole, Allen County encompasses approximately 660 square miles, so the warning polygon included less than a fourth of the county’s total area. The tornado’s entire path remained within the warning polygon, so people outside the polygon were not in danger.
Nearly half of all respondents indicated that they knew immediately whether they were within the warning polygon. Another quarter of respondents knew within five minutes whether they were in the warned part of the county. Nearly 18 percent, however, never knew with certainty before the storm passed whether they were in danger.
How soon respondents knew if they were in the warned area.
Best sources for location information
Among respondents who knew immediately whether they were within the warned area, nearly a third received their initial warning via their mobile phones, 24 percent via TV, 11 percent via NOAA Weather Radio and eight percent each via broadcast radio, amateur “ham” radio or outdoor warning sirens.
Among those who never knew with certainty before the storm passed whether they were in the danger area, there was a tie for the top response on how they first learned of the warning; 26 percent each reported TV and outdoor warning siren. A fifth received initial word of the warning from someone they know and 17 percent received it via their mobile phones.
Performance of outdoor warning sirens
Locations of outdoor warning sirens in Allen County, Indiana, from map provided by the website of the Allen County Office of Homeland Security. Yellow symbols indicate intermittently operating sirens. Red indicates a siren known to be inoperative.
Every operating outdoor warning siren in Allen County, including sirens miles southwest of the warning polygon, sounded shortly after the NWS issued the tornado warning.
Slightly more than 59 percent of respondents reported hearing an outdoor warning siren sometime during the hour of the warning, even if it wasn’t their initial warning source. Nearly 41 percent of respondents never heard an outdoor warning siren. The survey did not ask respondents whether they were outdoors at the time of the warning.
Respondents whose initial warning came from outdoor warning sirens were nearly evenly split with regard to their awareness of whether they were actually in the warned area. Slightly more than 24 percent reported knowing immediately, nearly 28 percent reported knowing within five minutes, nearly 21 percent said they knew within 10 minutes and nearly 28 percent indicated that they never knew with certainty before the storm passed whether they were in the warned area.
How soon respondents whose first waning came from an outdoor warning siren knew whether they were in the warned area.
Of respondents who got their first notifications of the warning from outdoor warning sirens, more than three fourths were within the city limits of Fort Wayne at the time. Seven percent were in the city of New Haven and no more than four percent reported being in any other location within Allen County. The vast majority of the county’s outdoor warning sirens are located within Fort Wayne and New Haven. Approximately 71 percent of Allen County’s population resides in Fort Wayne and probably even more are employed in Fort Wayne.
People close to the warning
Only seven percent of respondents reported that at the time of the warning, they were in the city of Woodburn, the town of Leo-Cedarville or rural northeastern Allen County (in other words, in or near the warning polygon) at the time of the warning. Of those, the initial warning source was more evenly divided, with 25 percent each reporting mobile phone or television and nearly 17 percent each reporting NOAA Weather Radio, outdoor warning siren or amateur “ham” radio.
Only a third of these respondents reported ever hearing an outdoor warning siren, even if it wasn’t their initial warning source. Eight percent never knew with certainty before the storm passed whether they were in the warned area.
Conclusions
Readers should use caution drawing conclusions from these data, because the survey that generated them was informal, not scientific, and the number of respondents fell far short of the number required for a representative sample of people who were in Allen County at the time of the warning.
In terms of improving the tornado warning system, it would appear that steps to increase awareness of warned locations could be helpful. Outdoor warning sirens, of course, do not provide location information. For that reason, it’s surprising that some respondents who reported initially receiving the warning via outdoor warning sirens also reported knowing immediately whether they were in the warned area. Because Allen County activates all of its sirens for every warning, citizens cannot assume that their ability to hear a siren indicates that they are near the warning polygon, but it’s possible that some people do not realize this and that additional public education might be helpful.
Readers might be surprised that a number of respondents who initially received the warning via television were not immediately aware of whether they were in the warned area. If we assume the TV meteorologists who were on the air live at the time described the warned area, it is possible that those respondents initially learned of the warning not from live meteorologists, but from on-screen textual information.
Finally, it appears that a significant portion of people initially learned of the warning via their mobile phones. The time of day might have skewed those results, because many people were likely commuting at the time, and therefore away from TVs and weather radios. Also, commuters would have been more likely to hear outdoor warning sirens than would be people inside workplaces or homes. Still, it’s possible that the Wireless Emergency Alert system that’s enabled by default on all modern smartphones proved itself to be a valuable source of warning information.
