CHARLOTTE, N.C. — During severe weather season, severe thunderstorm warnings and flash flood warnings are common.
The polygons look the same on the maps, but the actual report will have layers (three tiers) called impact-based warnings, that determine when we will be notified on our phones.
Severe thunderstorm warnings broken down
Severe thunderstorm warnings can happen any month of the year in the Carolinas, but they become a lot more frequent starting in March and April. As of 2021 though, a severe thunderstorm warning is broken down into three tiers.
BASE, CONSIDERABLE and DESTRUCTIVE
A severe thunderstorm warning is issued when a storm could or is producing winds at 58 mph or greater or quarter-size hail. This would be a BASE warning.
Tier 2 is CONSIDERABLE. This means this severe thunderstorm can produce winds of 70 mph and/or hail up to the size of golf balls (which is 1 3/4 inches in diameter).
The most severe tier is DESTRUCTIVE. These storms could produce hurricane-force wind gusts of 80 mph or greater and/or hail the size of baseballs (2 ¾ inches in diameter)
Only severe thunderstorms with a DESTRUCTIVE tag will notify your phone from the Wireless Emergency Alert system or WEA.
Flash flood warnings broken down
Flash flood warnings are issued when a sudden, violent flood happens most commonly after heavy rain.
Flash flood warnings are broken down into BASE, CONSIDERABLE and CATASTROPHIC.
BASE is issued most of the time when flash flood danger and damage is possible.
CONSIDERABLE is used rarely. This means flash floods are imminent and urgent action to protect lives and property.
The worst case scenario is CATASTOPHIC. At this point, floodwaters have risen to or are rising to historic levels and the flood threat is life-threatening and any damage could be devastating.
The only step above this level would be a FLASH FLOOD EMERGENCY.
The last Flash flood emergency for our area was from Hurricane Florence in 2018. Your phone will only notify you for a considerable or for a flash flood emergency. So take it seriously like all warnings when you get the alert.
Tornado warnings
Your phone will always receive a Wireless Emergency Alert for any tornado warning. In rare cases, a tornado emergency will be issued, meaning a large, deadly catastrophic tornado has been confirmed.
Knowing the degree of these warnings is important knowledge to keeping you safe this severe weather season. So take every warning seriously.
Recap: The Wireless Alert System will ping your phone for the following
- Severe thunderstorm with a destructive tag
- Flash flood warning with a considerable tag
- Flash flood emergency (catastrophic flash flood)
- Tornado warning
- Tornado emergency