CHARLESTON, S.C. (WCBD) – With severe weather expected across the Lowcountry on Thursday, it’s a good time to make sure you know life-saving weather terms.
One of the most common questions we receive during severe weather: what is the difference between a watch and a warning?
A WATCH mean conditions are favorable for severe weather to develop, whether it is a tornado watch or severe thunderstorms watch.
When a watch is issued, make sure your family’s severe weather plan is in place, just in case a warning is issued for your area.
WARNINGS are issued when severe weather is seen by a weather spotter or is Doppler radar indicated, like a severe thunderstorm or a tornado.
When your county or area is under a warning, that is when you need to enact your severe weather plan.
If a severe thunderstorm warning is issued for the area, you need to move indoors and away from walls and windows. If a tornado warning is issued for your area, you need to move into your safe place; this would be the lowest level of your home, in an interior room, away from any windows. You should stay in your safe place until the warning is lifted.
A MOMENT OF SCIENCE: Watches vs Warnings – an explanation with cookies
Storm Team 2 Meteorologist David Dickson recently explained the difference between a watch and a warning using a cookie-baking method.
The oven is preheated, I’ve got all the ingredients and components to make cookies right here, we just haven’t done it. This is our watch – the atmosphere is all set for severe storms to form, but they haven’t yet, so we must be prepared. This does not mean that severe storms WILL occur- I could just as easily turn off the oven and put the dough in the fridge for another day, but it is likely- why would we stop if we came this far?
Once they’re in, and we can observe the cookies forming, we got our warning– which means we have to immediately take action as we can observe cookies (or severe storms via radar).
According to Ron Morales, with the National Weather Service in Charleston, these warnings come with at least an 80% confidence that severe weather is occurring. It doesn’t get to 100% until they get confirmation from damage reports. For our cookies, the confirmation comes when we can finally try them.
That’s enough food analogies for now as there is a difference in how watches and warnings are issued.
Watches, both severe thunderstorms and tornados, are not issued by your local National Weather Service office, rather by the Storm Prediction Center in Norman, Oklahoma. The SPC watches areas for severe storm development on a national level, days before the event, and the day of.
“They’ll propose a watch area. They will contact the local NWS offices in that area, a coordination will occur via a conference call, of which counties to keep in or add or take out,” Morales says.
Once that is finalized, the watch will go out. The NWS office is then able to adjust that watch as the day goes on, removing areas early as storms clear the area, or by canceling the watch early.
Until then, the local NWS office has their work cut out for them- determining which storms are or will become severe. This is not an easy task as they monitor storms, sometimes many, minute by minute- watching for signs and signals from radar. Once a decision is made, a rapid process begins to draw the warning polygon, include what hazards are in those storms- whether it’s severe wind gusts, large damaging hail, or a tornado, and push that out to everyone via the emergency alert service or EAS.
I hope this trip behind the scenes helped clear up any confusion with where these alerts come from and what they entail. However this is just the start, have some way to receive these alerts no matter where you are and have a plan in place to act quickly.
DOWNLOAD THE APP! Now is a good time to download the Storm Team 2 Weather App, search for WCBD WX in your phone’s app store (click here for the Apple App Store | click here for the Google Play Store.) Make sure you have location settings and alerts turned on – the app will alert you if a watch or warning is issued for your area.