(KNWA/KFTA)- Well I certainly hope that this week has been informative on the subject of severe weather preparation. We covered quite a few topics. Monday thru Wednesdays topics were covered in a previous blog. If you haven’t read that yet I would encourage you to! There was a lot of important information covered in that article. https://www.nwahomepage.com/weather/weather-blog/severe-weather-awareness-week-2020/
The final three topics covered this week were severe thunderstorms, watches vs. warnings, and finally social media communication.
The two main categories of severity that are examined in a thunderstorm are the wind and the hail. In order to be labled as a severe thunderstorm by the National Weather Service the storm must be producing at least 58 mph winds and or at least quarter sized hail (1 inch) and or a tornado. All three factors could be present at once hence the use of and or. A storm really only needs one of these in order to be deemed severe. The flash flooding or lightning DOES NOT make a thunderstorm severe.
The simple question to ask to determine the difference between a severe thunderstorm watch or warning is…Is the storm occurring at this moment or moving my way soon? If the answer is yes then a warning is issued. The watch simply means that the atmosphere is ripe for severe thunderstorms to develop. More on the difference between a watch or warning to come later on in this blog.
Here are some of the numbers associated with severe thunderstorms. The first two numbers represent hailstone records. The largest hailstone of this past year was 4.6 inches in diameter and occurred on June 19th in Polk Co AR. The largest in state history was 5 inches in diameter. Over a billion dollars in damages is done in the US on average from hail alone. The next two numbers deal with the severe criterion for thunderstorms. The last fact is just impressive to think about. At any moment there are around 1800 thunderstorms occurring all over the world! That’s a lot.
Watches and Warnings
Our next topic was centered on the differences between a severe watch or warning. The image I created above I think really helps someone understand the difference between the two. I borrowed the illustration from fellow broadcast Meteorologist Brad Panovich at WCNC in Charlotte, NC. He used cupcakes, but I didn’t want to copy him exactly so it was cookies instead.
A watch is when the ingredients for severe weather are present and are coming together just like a cookie recipe. The typical ingredients we watch for create the acronym SLIM which stands for shear, lift, instability, and moisture. All of these don’t have to be present necessarily for severe weather to occur, but it is certainly more likely to occur with all four present. A warning is issued when the severe weather is imminent or occurring. To go back to our illustration, the cookies are baking or freshly out of the oven! Sorry if I made you hungry.
Here are some more differences between a watch and warning. Watches typically are issued by the storm prediction center and include several counties or states. Warnings are issued by your local national weather service offices and can be issued for multiple counties at a time. Watches are valid for about 6 hours while a warning typically lasts for an hour or less.
It used to be that the only way you could issue a warning for was the whole county. Good at warning vast amounts of people of severe weather, but it is also a good way to raise the false alarm rate as well. A tornado is not a very large circulation and can be up to a few miles wide for the largest of them. Even a few miles doesn’t span an entire county, so the NWS started issuing storm based warnings or polygon warnings instead. This is a more accurate way to track where the storms impacts might be felt, but warnings still get issued for the entire county usually. With the advent of newer technology some services like WeatherCall, do issue warnings only for those in the polygons. We have more information on WeatherCall on our website nwahomepage.com under the weather tab.
Social Media Communication
The final topic covered this week was social media communication. Social media is a great platform to use to prepare and inform you all of the details for upcoming severe weather episodes days in advance! This allows us to keep you up to date with the latest in between news casts. All of the NWA Weather Authority Team has social media accounts. You can see what they are called and on which platform they belong to on the graphic above. Our Instagram are the same as our Twitter handles. I would highly encourage you to find and follow us on them in order to stay weather aware during the upcoming severe weather season.
There are more than one way to receive weather alerts this season that we provide to you all. The first is obviously on air. We also use our apps, both the NWA Weather Authority App and the KNWA app, to share severe weather information. We also live stream during severe weather events on our website and on Facebook. Severe weather watches and warnings are also distributed on these local radio stations listed above.
Most importantly stay safe this severe weather season and lets try to keep our fatalities state-wide down to ZERO! Download our NWA Weather Authority App and stay weather aware.