severe-weather

Chicago, Detroit Face a Risk for Severe Weather on Saturday

Dennis Mersereau · 09/19/14 02:02PM

It looks like the weather over the United States will briefly get interesting again over the next few days, and as with all interesting weather, it spells danger for millions of people. Areas from Chicago to Detroit are at risk for large hail, damaging winds, and possibly an isolated tornado tomorrow.

Dangerous Severe Weather Outbreak Possible in the Midwest on Sunday

Dennis Mersereau · 08/30/14 02:17PM

After a long period without any severe weather, the atmosphere appears primed for a potentially dangerous severe weather outbreak tomorrow across areas from Kansas to Minnesota. Some areas could see tornadoes, baseball-size hail, and winds in excess of 75 MPH.

Mensch Montana Storm Ruins Rick Springfield Concert, Frees Alpacas

Dennis Mersereau · 08/19/14 01:04PM

Chaos and relief erupted at a county fair in Montana over the weekend after a severe thunderstorm tore down two crowded tents and stopped a Rick Springfield concert from happening. The storm also set free a majestic herd of alpacas, bless its heart.

Tornadoes Are Possible Today Over Areas That Rarely See Tornadoes

Dennis Mersereau · 07/27/14 01:39PM

A severe weather outbreak is ramping up over parts of the eastern United States this afternoon, with an area that doesn't typically see much severe weather bearing the brunt of today's action. The risk for EF-2 or stronger tornadoes is 1000 times higher than normal in some spots.

Dangerous Severe Weather Outbreaks Likely Today and Tomorrow

Dennis Mersereau · 07/26/14 01:06PM

A large part of the eastern United States is on track to see two distinct and very dangerous severe weather events both today and tomorrow, with the worst outbreak expected to occur tomorrow over the Ohio Valley and Mid-Atlantic regions.

Here Are Maps of All 38,728 Tornado Warnings Issued Since 2002

Dennis Mersereau · 07/23/14 01:30PM

Over the past twelve years, we've seen tens of thousands of tornado warnings across the United States. Almost every major city east of the Rocky Mountains has seen a tornado warning at some point since 2002, and the resulting maps are pretty cool looking.

Why Is a 30% Chance of Rain Different from a 30% Risk of Tornadoes?

Dennis Mersereau · 07/11/14 01:00PM

When the forecast calls for a 30% chance of rain, it's reasonable to think that the chances of seeing rain are 3 out of 10. But when the forecast calls for a 30% chance of tornadoes, the risk is much higher and much more dangerous. Why is there such a discrepancy between severe weather and rain forecasts?

Dennis Mersereau · 07/09/14 01:53PM

I wrote a piece for the Washington Post's Capital Weather Gang detailing the science and legacy behind the National Weather Service's definition of "severe weather," including why the threshold for severe wind is 58 MPH and why the size of severe hail jumped from penny to quarter size in 2010.

Dennis Mersereau · 07/08/14 10:36PM

The Storm Prediction Center's moderate risk for severe weather fell flat today, with most of the severe weather occurring all around the area at highest risk but not much inside of it. Busts happen. They're good for residents but bad for forecaster verification. When it comes to the "crying wolf effect," though, we're actually lucky this kind of bust isn't commonplace.

Widespread Damaging Winds Likely Today in Pennsylvania and New York

Dennis Mersereau · 07/08/14 01:28PM

A moderate (4 out of 5) risk for severe weather exists across parts of Pennsylvania and New York this afternoon ahead of thunderstorms that could produce widespread damaging winds in excess of 75 MPH at times. In addition to the wind risk, hail the size of ping pong balls and even a tornado or two are possible.

Washington D.C. and New York City Could See Severe Weather Today

Dennis Mersereau · 07/02/14 03:06PM

Intense thunderstorms are bubbling up along much of the East Coast this afternoon, some of which are turning severe. The worst of the storms are occurring eastern New York right now, and they may threaten New York City by rush hour.

A Derecho Is Racing Towards Chicago and Milwaukee With 60-80 MPH Winds

Dennis Mersereau · 06/30/14 04:39PM

"This is a particularly dangerous situation," says the Storm Prediction Center as a derecho is hauling eastward towards the Chicago metro area after producing 80 MPH winds across Iowa. The line should reach the Chicago metro area during rush hour, sometime between 530 and 630 Central Time this evening.

Widespread Damaging Winds Likely in the Midwest Today

Dennis Mersereau · 06/29/14 10:19AM

Parts of the Midwestern United States could see some powerful thunderstorms today, some of which could be extremely strong, producing winds in excess of 75 MPH. Due to the heightened threat, parts of Iowa, Nebraska, Missouri, and Kansas are under a moderate (4 out of 5) risk for severe weather.

This One Little Programming Tweak Will Save Thousands of Lives

Dennis Mersereau · 06/18/14 02:23PM

One of the best technological advances in the past year didn't involve any new technology at all — the advance is the result of an ingenious programming tweak developed by the National Weather Service. It will ultimately save thousands of lives over the coming years.