Stories tagged weather

Jul
14
2007

In hot water: These thermal imaging maps show the difference between normal surface water temperatures and El Nino surface water temperatures in the Pacific Ocean. (Photo from the National Oceanic and Atmospheric Administraion Photo Library)
In hot water: These thermal imaging maps show the difference between normal surface water temperatures and El Nino surface water temperatures in the Pacific Ocean. (Photo from the National Oceanic and Atmospheric Administraion Photo Library)
As if our TV meteorologists didn’t have enough warnings and ratings to rattle our cages with, here come two more.

The Climate Prediction Center as announced that it has created a rating scale to measure the impacts up oncoming El Nino or La Nina weather patterns. The new ratings will likely first be issued starting this fall.

Not only will the weather patterns carry a rating on their severity, but warnings and advisories will also be issued through the new program, much like we get thunder storm or tornado warnings or watches. Here are the details:

• A watch will be issued when conditions are ripe for the creation of El Nino or La Nino patterns within the ensuing three to six months.

• An advisory will be issued when the conditions are underway.

• The rating scale will go from 1 to 5 and be done to measure the impact of the El Nino or La Nina after it’s passed, much like the F-scale used to measure tornados.

The strength of the weather conditions is determined by the warmth or coolness of the surface waters in the South Pacific. The names were given to the weather conditions by fishermen from Peru who noticed fluctuations in their catches based on the changing water temperatures.

The new scale will have a bigger impact on allowing researchers to compare weather conditions after they’ve happened, not in predicting how severe new ones will be.

Strong El Ninos and La Ninas can impact weather conditions worldwide. You can learn more about them at the Science Museum of Minnesota's Science on a Sphere display.

Jun
21
2007

Tidal surge from the 1938 hurricane: Image courtesy NOAA/NWS Historic Collection.
Tidal surge from the 1938 hurricane: Image courtesy NOAA/NWS Historic Collection.
Over on our thread about a crazy catfish skull, "brandon" recently left a rather off topic, yet still intriguing question:

hi there! i was wondering if there was a hurricane in new york in 1930???????

Why, yes, there was. Technically, it happened in 1938, and it was quite the whopper. On Friday, September 16th, 1938, a Brazilian ship reported a huge storm in the Atlantic and weather forecasters expected it to make landfall near Miami. Luckily for Miami, the storm turned north and everyone expected it to head out to sea. Remember: this was long before satellite images allowed us to track these huge storms in real-time.

Unluckily for people who lived in New York, Rhode Island, and Connecticut, though, the storm had just temporarily headed out to sea and was about to make landfall in New England. On the 21st, with no warning, one of the fastest-moving hurricanes ever recorded slammed into the New England coast. It caused massive damage in Long Island, giving the storm the name "The Long Island Express." Nearly 600 people died by the time it was all over.

Can you imagine what a storm like that would do to this area today? In 1938, Long Island was still somewhat rural and undeveloped. Today it's a densely-packed urban area full of millions of people, homes, and businesses. And, quite honestly, I hadn't ever even heard of this storm until today. I often think of New York as immune to these sorts of major storms. But it's actually very likely that a major storm will affect this region again in the next 50 years.

1938 Hurricane Links

The Great Hurricane of 1938 - a very in-depth history of the storm.
History Reveals Hurricane Threat to New York City - A modern perspective on the risks to New York city.
The regional perspective on the 1938 hurricane - Lots of great pictures of the destruction in Connecticut and Rhode Island.

Do you know anyone who remembers the 1938 hurricane? Do you live in this area and have a hurricane story? Share your stories.

Tornado trail seen from space: Tens of thousands of trees were leveled June 7, 2007 in Wisconsin.
Tornado trail seen from space: Tens of thousands of trees were leveled June 7, 2007 in Wisconsin.

A tornado left this scar in a forested region of Wisconsin on June 7, 2007. Click on the picture to get a little larger view or here is a link to the original NASA photo.

New Scientist has a great in-depth feature debunking 26 myths that regularly get in the way of discussing climate change. Its good to see a cohesive guide to this complex issue.

Apr
18
2007

Ever wanted to be a storm spotter? Now's your chance! The National Weather Service (NWS) relies on local SKYWARN storm spotters to confirm, from the ground, what meteorologists are seeing on radar. NWS storm spotters are not tornado chasers like the folks in the movie "Twister." Instead, they report wind gusts, hail size, rainfall, cloud formations, and the like to NWS and local emergency management agencies.

Tornado: This tornado, seen in its early stages of formation over Union City, Oklahoma (May 24, 1973), was the first one caught by the National Severe Storms Laboratory doppler radar and chase personnel. (Photo courtesy NOAA Photo Library, NOAA Central Library; OA
Tornado: This tornado, seen in its early stages of formation over Union City, Oklahoma (May 24, 1973), was the first one caught by the National Severe Storms Laboratory doppler radar and chase personnel. (Photo courtesy NOAA Photo Library, NOAA Central Library; OA

New radar equipment is still not sensitive enough to determine the existence of an actual tornado. It can only predict where severe weather is likely to occur. So the NWS needs trained volunteers to verify actual severe weather.

With peak storm season just around the corner (mid-June here in the Upper Midwest), free, 2.5-hour classes are being offered to train new SkyWarn volunteers.

SkyWarn class schedule, greater Minnesota
SkyWarn class schedule, Twin Cities Metro area

Here's how you get started...

Apr
03
2007

The 2007 Atlantic hurricane season officially begins June 1 and runs through November 30.

Two hurricanes: This satellite image, captured 8/30/05, shows Hurricane Iris in the central Atlantic Ocean, with Tropical Storm Karen to the southeast. (The original image, from which this is cropped, also showed Hurricane Humberto moving northeast across the Atlantic.)
Two hurricanes: This satellite image, captured 8/30/05, shows Hurricane Iris in the central Atlantic Ocean, with Tropical Storm Karen to the southeast. (The original image, from which this is cropped, also showed Hurricane Humberto moving northeast across the Atlantic.)

Check back often for the latest predictions, forecasts, and discussion.

Mar
22
2007

Super size me: With more concentrated efforts on researching the topic, scientists now believe that super snowflakes do exist. They can measure between three and six inches in width and be the size of table plates.
Super size me: With more concentrated efforts on researching the topic, scientists now believe that super snowflakes do exist. They can measure between three and six inches in width and be the size of table plates.
Spring is finally here and what better topic to bring up than snow, right?

A story in the New York Times this week is providing more evidence about “super snowflakes.”

For ages artists and writers have waxed poetically about huge flakes of snow. Hollywood movie producers and Hallmark card creators have used those images to depict winter. But they’re just figments of our imagination, right?

Hard scientific data is now being collected about the size of snowflakes, the researchers doing that work have been pleasantly surprised. They’ve found that snowflakes measuring from 2 to 6 inches wide regularly fall around the world. Some reports about the “super flakes” say that they’re so large – the size of saucers or plates – that their edges turn up and centers sag due to their weight.

A snowflake expert from the California Institute of Technology points out that there’s scientific basis that limits the size of snowflakes. But, he points out, large snowflakes may often break apart due to the pressures from high winds hitting them as they fall to the Earth.

For ages, scientists had never really measured the size of snowflakes. But on some recent research trips, researchers have seen snow falling that measured two or three inches in size. That’s spurred on more interest – and research – into the size of snowflakes.

In the future, some of that research may be done from space. NASA will be launching a global satellite in 2013 that will monitor global precipitation patterns. That technology will be able to gauge the moisture in each rain or snow fall, along with the size of the flakes falling.

Jan
16
2007

It's cold this morning. Maybe the coldest morning of the season so far? Luckily, there's also a lot of sunshine, and almost no wind.

If it were windy, you'd hear the weather forecasters talking a lot not only about the air temperature (-6 degrees when I left the house), but also about the "wind chill." Wind chill is a way to describe how quickly heat is transferred from your body to the atmosphere when it's both cold and windy outside. As wind increases, more heat is drawn from your body, decreasing your skin temperature and eventually your internal body temperature. Wind chill makes it feel much colder than it actually is.

Last year, I overheard a woman in the Science Museum parking garage elevator talking about how she parks her car in a sheltered area to protect it from wind chill. She was worried that, if she left it in a more exposed area, it wouldn't start. I can't say anything about the state of her car battery, or condensation on her distributor, but I can say that wind chill has very little impact on cars or any other inanimate objects: wind will shorten the time it takes for an object to cool to the temperature of the surrounding air, but it won't get any colder than that no matter how much wind there is.

For humans and animals, though, wind chill affects how quickly hypothermia and frostbite can occur. Hypothermia is a condition in which core body temperature has fallen to the point where normal muscle and brain functions are interrupted. (Thor did a post about hypothermia a few weeks ago.) Frostnip/frostbite are conditions in which body tissues freeze. Knowing the wind chill helps us make decisions to avoid these and other cold weather dangers.

She's got the right idea: Bundle up! (Photo by Yann Richie)
She's got the right idea: Bundle up! (Photo by Yann Richie)

The best thing to do when there's a significant wind chill is to stay inside. But you can't stay at home on the sofa all winter. So what can you do? Dress right when you go outside. That means wearing several layers of loose-fitting, lightweight, warm clothing. (Trapped air between the layers will insulate you and keep you warm.) Stay dry. (Remove layers if need be to avoid sweating and later being wet and cold.) Wear a tightly woven, water repellent, hooded top layer. Cover your mouth to protect your lungs from the cold. Mittens, which allow your fingers to share warmth, are better than gloves. And your mom was right: wear a hat! Half your body heat can be lost from your head.

Dec
19
2006


Snow chance: Using data collected over the past 30 years, here are the statistical probablities of having a white Christmas in various parts of the United States.

Will Bing Crosby be singing the blues this year?

He, along with anyone else hoping for a White Christmas, might want to check out this probability map for the chances of having a white Christmas in the United States. As you can see, Minnesota and the upper Midwest are among the prime locations to have a white Christmas.

U.S. weather records averaged over a 30-year period show that only five places with long-term weather records are practically guaranteed to have a white Christmas. They are Marquette and Sault Ste Marie in Michigan, Hibbing and International Falls in Minnesota, and Stampede Pass in Washington.

As the map shows, wide areas of northern Minnesota and Wisconsin, much of Michigan's Upper Peninsula, and western mountains including the Cascades of Washington and Oregon, California's Sierra, and the Rockies from Montana and Idaho south into southern Colorado have a better than 90% chance of snow on the ground at Christmas.

Of course, from year to year the weather varies. There’s never a guarantee of a having a white Christmas. How important is it to you to have a snow during the holidays?

Nov
28
2006

Roger Ledding, former chief of the Minnesota State Patrol, was on WCCO radio this morning, talking about the high number of traffic accidents during today's am rush hour.

No snow, no ice, so what's the problem?

Well, it's been very dry in the Twin Cities lately. A fine spray of oil from cars routinely covers road surfaces. In very dry weather, that oil can build up. When rain begins to fall, it mixes with the oil and the road surface becomes extremely slippery. It can take a few hours for additional rain to break down and wash away the mess.

Also, this morning's wasn't a gentle, soaking rain, but a downpour. That left standing water on roadways. Drivers traveling too fast found themselves hydroplaning--sliding on a thin film of water, unable to stop or steer.

It's been unseasonably warm, for sure, and I wasn't thinking about hazardous driving conditions on my way in to work this morning. But I will be on the way home...