Severe Thunderstorm Warnings Today Have Three Levels. Most People Know One

If you're looking for a severe thunderstorm warning today, the fastest honest answer is the Live Emergency Map, which shows active National Weather Service warnings on one national view.

What this page does is the part the map can't: explain what the alert you're looking at actually says about the next hour, because the same three words carry three very different levels of threat.

Read the Tag Before Anything Else

Since 2021 the National Weather Service has attached a damage threat category to these warnings, and it tells you more in one word than the rest of the text does.

No tag. The baseline: 58 mph winds and/or hail an inch across. Enough to bring limbs down on cars and power lines. Go inside, stay off the road if you can.

Considerable. 70 mph winds and/or hail an inch and three quarters — golf ball. This is where cladding, windscreens and roofs start taking real damage.

Destructive. 80 mph winds and/or hail two and three quarter inches — baseball. This is the only category that triggers a wireless emergency alert on phones, and it is the one to treat like a tornado warning: interior room, away from windows, now.

The consequence of that last line is the single most useful thing on this page. If you rely on phone alerts alone, you will never be told about most severe thunderstorm warnings. They simply aren't pushed. A NOAA weather radio carries all of them — see NOAA Weather Radios.

What the Warning Text Is Telling You

The alert carries more than a headline, and three parts are worth finding.

The hazard line states the expected wind speed and hail size. That's the concrete forecast — "60 mph wind gusts and quarter size hail" — and it's what you should be reacting to rather than the word "severe".

The source line says whether this is radar-indicated or confirmed by a spotter. Both are real; a confirmed report means someone has actually seen it happen.

The expiry time tells you how long the polygon is in force. Warnings are short by design, usually well under an hour, and they get reissued for the next area downstream as the storm moves.

A tornado can be added mid-event, and a severe thunderstorm warning is sometimes upgraded. That's why "it's only a thunderstorm warning" is a bad basis for staying upstairs.

The Hour Before, and the Hour After

Before. If a watch is out, the useful work takes ten minutes: bring in furniture, bins and anything light, park away from trees, charge phones, and put shoes near the interior room. That's it — the rest of the day continues.

During. Inside, away from glass, off the road. If the tag is destructive, treat it as a tornado warning and go to the interior room you already chose in Tornado Preparedness.

After. This is where people get hurt, because the danger feels over. Downed lines stay live. Wet limbs still fall. Standing water hides road damage and carries current from anything energised.

If a tree has come down on the house, a vehicle or a line, that's a job for someone insured and equipped — not a chainsaw and a neighbour. What to do in the first hours, including who to call and what your insurer will want photographed, is in Storm Preparedness & Kits.

And if the watch-versus-warning wording is the confusing part, Severe Thunderstorm Watch vs Warning settles it in two minutes.

Learn the three tags tonight. It takes a minute and it changes how you read every alert you get from now on.

FAQ: Severe Thunderstorm Warnings Today