Weather FAQ
Big weather words, explained simply. This page is made so families can understand what the alerts mean and what to do next.
First Rule
If you see a Warning, move to your safe place right away. If you see a Watch, get your plan ready and stay close to weather updates.
Watches And Warnings
What is a Severe Thunderstorm Watch or Tornado Watch?
A Severe Thunderstorm Watch means storms could organize and produce large hail (1 inch or bigger) or damaging wind in the next few hours (often 2 to 8 hours).
A Tornado Watch includes those threats and also means tornadoes are possible in that watch area.
What is the difference between a watch and a warning?
Watch: severe weather is possible soon.
Warning: severe weather is happening now or expected very soon, usually within about an hour.
Why are watches not issued for every severe storm?
Some severe storms are small and short-lived. Watches are mainly used when the severe threat is more organized and likely to last for hours across a larger area.
What does “Particularly Dangerous Situation (PDS)” mean?
PDS wording is used for rare, very serious setups. In tornado cases, it usually means forecasters think strong, long-lived tornadoes are more likely than usual.
It can also be used in severe thunderstorm watches for major damaging wind events. PDS is uncommon and should be taken very seriously.
Convective Outlook Questions
What do Marginal, Slight, Enhanced, Moderate, and High mean?
These are risk levels for organized severe storms. They step up in danger from Marginal to High.
On this site, brighter and stronger colors mean stronger storm danger.
What do the probability percentages mean?
They show the chance of severe weather within about 25 miles of a point (roughly metro-area size), not for one exact house.
Why can percentages look low but still matter?
Severe weather is uncommon at one exact spot. So even a number like 10% can be a big signal compared to a normal day and should be treated seriously.
What is the light green area on Day 1 to Day 3 maps?
That area means regular thunderstorms are possible (non-severe). Even then, lightning can still be dangerous.
Severe Weather Basics
How is severe thunderstorm weather defined?
A severe thunderstorm can include hail at least 1 inch wide, wind gusts of 58 mph or more, or a tornado.
What is a “significant severe” thunderstorm?
This is a stronger level: hail at least 2 inches, wind gusts of 75 mph or more, or tornado damage at EF2 or stronger.
What is a tornado?
A tornado is a violently rotating column of air connected to both the ground and a thunderstorm cloud. It may have a visible funnel, but not always.
Tornado Questions?
Go To Tornado Basics Read evergreen tornado facts, myths, and safety actions in one simple page.Fire Weather Words
What is a Critical Fire Weather Area?
It means weather conditions can help wildfires start or spread quickly, such as very dry air plus strong wind, or dry thunderstorms with little rain.
What is an Extremely Critical Fire Weather Area?
This is a rare, higher-danger fire setup with very strong wind and very low humidity over very dry fuels. Fire spread can become extreme.