Friday, October 3, 2014

Recap of Oct. 2 severe weather, challenges faced, and a word on siren policy

Until last night, it had been a long time since widespread severe weather (not including biblical flooding events) had affected the Memphis metro. Tornado Warnings were last issued in late April. A well-advertised, and well-forecast, squall line moved through the region during the late evening hours bringing many reports of wind damage and several areas of rotation on radar. No reports of tornado touchdowns were received in the immediate area, though possible tornado damage occurred in northeast AR.

Every county in the metro was under a Tornado Watch and Severe Thunderstorm Warning as the line moved through and several areas were also under Tornado Warnings due to radar-indicated rotation in the fast-moving line. An early recap of the night from NWS-Memphis can be found here. They also discuss areas they intend to survey for storm damage.

Severe weather reports received by NWS as of mid-morning Friday. Most were wind or wind damage, though a possible tornado struck east of Jonesboro.
There are two main issues I want to address in this blog: 1) technology challenges and 2) outdoor warning siren policy.

Technology challenges

Technology. We love it for many good reasons. It allows us to do many things quickly and more efficiently than ever before. It allows us to push specific warning information to you via your smartphone almost as soon as it is issued by the NWS. But it also has its pitfalls. Namely when it doesn't work. Fortunately our critical warnings worked flawlessly last night, but there were other issues.

MWN StormView Radar on the website and mobile apps was one such problem. Due to multiple malicious attacks on multiple weather vendors' servers yesterday, including at least one big name and ours (though not targeting MWN directly), our radar stopped updating. The timing was awful. We apologize for and sincerely regret this major inconvenience; unfortunately some idiots like to "be funny" at other's expense. We're not laughing. If they can be tracked down, they ought to be prosecuted. We will be following up with our vendor on best practices going forward, but the outage was (and remains) completely outside of our control, though we take responsibility for providing the service to you.

In addition to radar issues, MWN headquarters lost internet connectivity as the squall line was moving across the river and Tornado Warnings were being issued (it also remains down this morning). This outage hampered our ability to disseminate information (including critical social media posts and data from our Bartlett weather station), monitor incoming data (including radar), troubleshoot the ongoing issues with our web radar, and communicate with the NWS. I'm not turning this into a bash-fest on our internet provider. This is the first outage we have had in months, perhaps over a year, and the connection handles everything we throw at it on a routine basis. The point is, once again, technology is not flawless and is subject to outage.

I want to take just a minute though to recognize MWN interns Kevin Terry and William Churchill for exemplary service last night as MWN's internet feed went down. Working from Mississippi State (there are advantages to working from disparate locations during severe weather events!), Kevin and William immediately took over nowcasting responsibilities in the middle of the event and didn't miss a beat. I'm guessing that most people watching our Facebook or Twitter feeds last night didn't know a major link in the chain had failed. That is a sign of a well-oiled machine and I thank them for their awesome work and dedication to all of you! My wife loaned her laptop to the cause (thanks honey!) and, courtesy of a smartphone hotspot, I was able to re-engage on a limited basis. Sometimes it takes a team effort and I've got one of the best in #TeamMWN!

Tornado Warnings and outdoor siren policy

The other discussion that needs to be had is regarding outdoor warning siren policies. Truth be told, it's been a relatively quiet couple of years for severe weather in the metro. Sometimes that "lack of practice" results in lack of preparation and awareness. The main issue we saw last night was in Shelby County, but the general principles apply most anywhere. Recall that Tornado and Severe Thunderstorm Warnings are not issued by county. They are "storm-based polygons," meaning they are drawn to reflect the forecast path of the suspect storm. Also recall that outdoor warnings sirens are for OUTDOOR use and aren't designed to be heard inside well-insulated homes with TVs and air conditioners on and storms overhead, and definitely not while you are sleeping. That being said, we recognize that many people are close enough to a siren to hear it indoors.

Siren policy differs by county, and in Shelby County it varies by municipality. The best siren policy is one that limits the activation to times when the community in the path of the storm is the only one alerted. To review, these are the policies in place in Shelby County as of October 2:

  • Bartlett, Collierville, and Germantown sound sirens for their cities (the entire city) only if the warning polygon intersects their respective municipal boundaries.
  • Shelby County sirens (including Millington, Arlington, Lakeland, and unincorporated areas of the county) sound for the entire county when any part of the county is warned.
  • City of Memphis sirens also sound for the entire city when any part of the county is warned.
  • However, Memphis is nearing implementation of a brand new system (the change should probably occur in November) that will activate sirens in Memphis only for those areas that are within the warning polygon, plus any sirens outside the polygon that can be heard within the polygon. Details on this policy change can be found here.

A Tornado Warning was issued at 11:13pm last night (shown below) that clipped the eastern side of Collierville. No other part of Shelby County was affected. In fact, the storms had exited all but the southeast corner of the county. However, given the above-stated current policies, sirens should have sounded in Memphis, Shelby County, and Collierville.  Bartlett and Germantown were not affected.

This was a case in which, under Memphis' new policy, sirens would NOT have sounded for any part of Memphis, which is exactly the way it should be. In our opinion, Shelby County should also move to a policy that allows segmentation of the sirens. There really was no reason to warn Shelby Forest, Millington, Arlington, or Lakeland about the storm in Collierville. I checked with Bartlett officials and sirens were not sounded in their city - well done! I also heard multiple reports last night that Collierville siren activation may have been delayed, and then continued after the warning for Shelby County was cancelled at 11:23pm (10 minutes after issuance). We can't corroborate that firsthand however.

Despite the sometimes untimely pitfalls of technology and some initial setup, the best way to receive warning information specific to YOUR location is smartphone weather apps with location-based warning technology. They can be set to warn specific points, regardless of county, and provide the most pertinent information to your location. Because of potential for technology issues, we also strongly advise a secondary means of receiving warning information that will wake you. The best secondary source is NOAA Weather Radio. Despite being county-based (all radios in Shelby County would have alarmed with the Collierville warning above), it's better than nothing, especially when you're asleep and local media is turned off in your home. Outdoor sirens are not to be relied on to wake you up.

We appreciate those who have trusted MWN and our StormWatch+ technology to provide the precision warnings described above. If you're interested in checking it out, click the appropriate link below. It's a fraction of the cost of a weather radio and only alerts you when necessary - plus it will wake you up in the event of the most severe storms. The precision is best demonstrated by an individual who lives on the west side of Collierville and indicated that StormWatch+ did not sound last night. As it turns out, he was less than a mile west of the warned area and not in harm's way. The technology worked as advertised.

To conclude, we thank you for your patronage and support of MWN, we apologize for the radar issues, and we greatly appreciate the dedication of #TeamMWN! If you have any questions, comments, or issues to raise, we would love to hear from you! Comment on this blog, hit us up on social media, or drop an e-mail via our contact form.

Erik Proseus, MWN Meteorologist

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1 comment:

Kevin said...

I want to say thank you for a job well done despite all of the challenges of technology.

I am sure you've considered a secondary ISP. An expense I understand is unwelcomed addition to the overhead. I've been there and would be happy to discuss further offline if you want.