April 28, 2008

HOCKEY FEVER -- well yes, and no.

Fans have the fever as the Penguins are indeed heading to the Stanley Cup Finals, but the weather in Pittsburgh is anything but feverish — it FEELS like hockey season with well-below normal temperatures for nearly the last two weeks! The Penguins’ yet-to-be-determined opponent will face the other end of the weather spectrum today in Big-D with thermometers nearing triple digits. So how do hockey venues deal with such extremes in weather? The short answer is … the best they can.

Sell-out crowds and excited fans can quickly heat up the ice in Mellon Arena, so the Allegheny County Sports & Exhibition Authority has actually rented cooling air conditioning units on a few occasions (including Sunday’s blow-out against the Flyers). However, newer hockey venues, such as Dallas’ American Airlines Center, are better equipped to handle the heat with an air conditioning capacity of 4600 tons and eight miles of pipe running under the ice to keep it frozen!

Ice maintenance itself is a science perfected over the years by a man whose last name hockey fans use routinely; Frank Zamboni. His working prototype, the Model A, was invented in 1949, but before then all ice resurfacing was done by hand! Today’s Zambonis travel three miles in an average hockey game, picking up nearly a ton of snow in between three periods of play and leaving behind 1200 pounds of water. With the preference for “fast ice” in NHL games, very hot water is used by the machines to more quickly and evenly melt the top layer of ice as the Zamboni cuts across. The average water temperature of ice resurfacers to ensure this fast ice is therefore between 140 and 145 degrees.

I didn’t realize there was two blogs’ worth of material on the “weather of hockey,” but I’ve learned a lot in the process. A “shout out” to my new friends at NHL Home Ice on XM Satellite Radio as well.

Go Pens!

Sources:
Post Gazette | Dallas Stars | Zamboni

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May 13, 2008 Games for the Pittsburgh Steelers and matchups at PNC Park can certainly be impacted (or even canceled) by the weather, but hockey?

With odds in favor of the Pittsburgh Penguins during the Eastern Conference Finals, I thought it would be interesting to look at (and do a two-part blog on) the meteorology of hockey -- and check out the picture of the rainbow over Mellon Arena, courtesy of Tim Tender at our sister station WJAC.

Those who maintain NHL arenas have to battle many of the same elements that can plague baseball and football fields, lest their players and fans end up in a fog as was the case in the 1975 Stanley Cup finals. In that series, a particularly humid day (and no air conditioning) caused a fog to form over the ice in the Buffalo arena. The game was postponed for a time as the Flyers and Sabres waved towels around to disperse the cloud over the ice!

These problems are most daunting for post-season games in warmer climates like San Jose, Tampa and Dallas, where even opening the arena doors for deliveries can bring impurities that will soften the ice surface. Air flow, humidity (which is impacted by outdoor weather) and temperature are factors that each NHL city has to monitor.

Most NHL ice surfaces are maintained between 15° and 23° F, but minimizing the chances of condensation will help to keep the ice “fast” (harder, smoother and colder). Therefore, the dew point temperature of the air immediately above the ice must be monitored to keep condensation from occurring. Pyrotechnics, the number of fans (warmer when they’re cheering) and even whether or not the pucks are kept in the refrigerator can alter the delicate balance between the arena temperature and that of the ice. Dehumidification and engineering the air flow through Mellon Arena helps to keep both the dry bulb and wet bulb temperatures in check. Go Pens!

Next up: (assuming the Pens keep winning); the science and temperature dependence of the Zamboni, so stay tuned!

Sources: exploratorium.edu/hockey, The Sporting News

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May 6, 2008 This is National Teacher Appreciation Week and I, for one, have nothing but admiration for the wonderful teachers around us. I often receive e-mails or letters from students aspiring to a career in meteorology and my advice always includes beefing up courses in math and physics, finding a job shadow experience and linking up with a mentor for support. Teachers are wonderful mentors and for many young people the single most important source of encouragement. I was fortunate to have immense parental support, but I can recall caring teachers who helped foster my interest in science throughout elementary and high school, even when that wasn’t seen as the most “natural” choice for a little girl.

If you’re a teacher, I applaud you and hope that you’ll cultivate the curiosity of the budding meteorologists in your midst. For the rest of us whose lives have been touched by a teacher (and whose hasn’t?), we might make an extra effort this week to let our appreciation for their guidance and knowledge be known.

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April 28, 2008

April showers may bring May flowers, but would you believe that April is historically one of the driest months for the Pittsburgh area? The summer months typically bring the rainiest periods to our region, with June topping the list (average of 4.12 inches) when you combine the amounts from the last 30 years.

In fact, (in order of wettest to driest) July, May, August, September, March AND November see more rain than April. April’s mean rainfall of 3.01 inches is lagged by only the snowy months of December, January and February!

We’re only a few days from the start of May which has an average rainfall of 3.8 inches, so more May blooms may indeed be on the way.

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April 15, 2008

'Tis The Time Of Year For Severe Weather … Or Is It?

You have likely heard about the rocky weather of the last few weeks, with an unusually high number of March tornadoes and serious river flooding in the central plains. Springtime can be synonymous with killer weather in many parts of the country, with most of our nation’s tornadoes occurring in the months of April and May. However, this climatology is for the region that experiences the majority of tornadoes, the southern and central plains (known as “Tornado Alley”).

The peak in severe weather moves steadily northward from the Gulf Coast in March to the Great Lakes in July and August. Although severe storms and tornadoes can happen any time of year, in western Pennsylvania they’re actually more likely in the summer months than in the spring.

You should never let down your guard though, as spring storms can quickly form damaging winds, flooding and hail. You can take a breather for the next several days though as our warmer, sunny weather will pose no threat.

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April 8, 2008

April Showers Bring … Rain OR Snow!

Even though we’re well into Spring, April is still a very transitional month in terms of weather in western PA. It’s not at all unusual to have thunderstorms and 70 degrees one day and sub-freezing temperatures the next! This week’s home-opener for the Pittsburgh Pirates was a beautifully warm and sunny day — perfect for baseball. HOWEVER ... last year’s home opener required hot cocoa. It was overcast with flurries and temperatures not climbing out of the 30s!

This can make it difficult to plan outdoor events very far in advance this time of year! Many of you have surely had unintentionally snowy garden weddings, thunderous company picnics, or the clouds literally raining on your parades. We’d love to hear how your unique Spring plans were interrupted by the weather. E-mail us your stories here.

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April 2, 2008

What Is “Normal?"

Although we often use the terms "normal" and "average" interchangeably, in the world of climatology, they actually mean different things.

As the daily low and high temperatures are computed each day, they become part of the weather record for each weather reporting station (now almost exclusively airports). Pittsburgh International Airport has been the official reporting station for Allegheny County since 1952. Both "averages" and "normals" are calculated from the resultant data, but in different ways.

Climatologically speaking, weather averages are composed using the entire weather record, whereas "normals" encompass a shorter period of time, usually 30 years.

The "average high temperature" for example in Pittsburgh on any given day is computed by taking the mean of all recorded high temperatures on that day from the period of record; for Pittsburgh International Airport, being 1952 to 2007. This value might be slightly different than the "normal high temperature" for the same date, which would be taken as the mean of all recorded high temperatures on that day from the last three decade-periods (1970-1979, 1980-1989 and 1990-1999). Beginning in the year 2010, the "normals" will be taken from the '80s, '90s and years 2000-2009. Make sense?

So, which values are you hearing/seeing in your daily forecast? Most likely, the "normals," which is what people have experienced on that day in the most recent years of record (and those that most viewers will remember). Although you’ll likely hear us use both terms to communicate the weather of the day, now you can impress (or worry) your friends at your next dinner party with the true meanings of the words.