Archive for the ‘WEATHER WORDS’ Category


Making the Call: 2014 Super Game Forecast
by Meteorologist Amy Freeze

First Ever Cold Weather Big Game takes place in East Rutherford, NJ at Metlife Stadium

10 Day Outlook for Feb. 2, 2014
High 37
Low 24
Winds NW 10-20mph
No Snow
Sunrise 7:05 am
Sunset 5:15 pm

How Weather Affects Football

I spent four seasons working with the Chicago Bears forecasting weather conditions for Soldier Field. Understanding weather changes prior to kickoff and during the game can definitely create a secret weapon on certain occasions. All opponents have to play in the same elements, but that’s not the bottom line. How athletes and even a coach approach extreme conditions in competition can make all the difference. Weather can often become a field advantage if you know what to look for and are ready to adapt. Before the game even begins, knowing the wind direction, speed and wind patterns in the stadium can help the coaches make their decision for the coin toss on which direction they want the game to begin. Knowing game time temperature and temperature changes during the game can help the home team pick a lighter jersey color in hot weather conditions allowing for cooler core body temperatures. Understanding the turf and how it might respond to incoming rain, impending freezing temperatures, etc allows equipment managers to adjust cleats and prepare for halftime adjustments. Wind direction and speed can help punters and kickers decide on angles, and understanding the wind may even affect a coach’s game strategy.

How Temperature Affects the Football

The temperature can affect how far the ball will travel, how easy it is to catch, even the impact of a punters kick. It has to do with physics.

Temperature can affect the ball in a few ways. There are a few variables to consider when looking at how a ball will be impacted in cold weather. The temperature can change the air pressure inside the ball which can make the ball seem over inflated effect if it was warmed, or and under inflated effect if it was cold. Here’s an example: A basketball that doesn’t have enough air in it won’t bounce that well. The bottom line is that the amount of air pressure for a ball is directly proportional to the temperature of the air. Colder = less inflated effect

Side note: Other types of solid core balls, like baseballs, golf balls also have temperature impact, but the mechanics are a bit different. Here the characteristics of the material inside the ball are responsible for the bounciness of the ball. For example the rubbery insides are affected by temperature, which impacts the ball’s performance.

Overall, a ball’s bounciness is dependent on the elasticity of its constructed materials. The characteristic of elasticity allows the ball to retain kinetic energy during a collision by having the ability to flex without breaking, the ball can then return to its original shape post bounce. This scientific measure of a ball and its material’s elasticity is called the coefficient of restitution. You can read about it in any high school Physics book. An object with a low coefficient of restitution will lose a great deal of its kinetic energy in a collision through breaking or deforming, or through the generation of sound or heat. Compare the kinetic energy transmission through steel balls suspended on strings as they bounce back and forth in an example of a high coefficient of restitution. Now consider a lump of clay or a piece of glass in a collision, both materials having very low restitution values – they simply do not transfer energy well because they are not as elastic.

But even materials that do can transfer energy well, like a rubber band can be affected by temperature. The colder a material gets, the less elastic it can be. Under cold conditions, the material can actually absorb energy rather than transferring it, giving it less movement or “bounce.”

Both inflated balls like footballs and solid core balls like a baseball rely on the principle of coefficient of restitution. A warmed, (over inflated) ball is more elastic and would likely be easier to grip, to catch, and to be punted farther.
While a cold, (under inflated) ball would be less easily handled and some athletes have described cold weather footballs like dealing with a brick!

There are plenty of game time examples of weather affecting football games and some are traced directly to temperatures!

New York Giants legend Y.A. Tittle played his biggest football games in cold climate weather. The Hall of Fame quarterback carried the Giants to three straight title games from 1961-63. The games were played in Green Bay, New York and Chicago. The Giants lost all three-title matchups. In the book “Tales from the New York Giants Sidelines,” Tittle told author Paul Schwartz that the Giants’ offense had meltdowns in cold inclement weather.
“Good Lord, I threw balls where the ball would come back and hit me in the face,” Tittle said of the 1962 game when winds whisked 30 to 40 mph. “It was miserable.” In 1963, Tittle’s last chance at a league championship, the Giants played the Chicago Bears in single-digit cold at Wrigley Field.
“We played on a field that Eskimos couldn’t have lived on,” Tittle told Schwartz. “It was frozen. It was just unbelievable.”
The most infamous cold weather field in the NFL The Frozen Tundra got its nickname during the Cowboys v Packers 1967 NFC Championship Game
On New Year’s Eve in 1967, Tom Landry’s Dallas Cowboys visited Vince Lombardi’s Green Bay Packers in the NFL Championship Game.

It has come to be known as The Ice Bowl and is, in fact, the coldest game in NFL history with the official game-time temperature registering at -15 F, with a wind chill at -47.2 F. As the referee blew the whistle to start the game, it froze to his lips.

The Packers came from behind in the final seconds of the game when Lombardi called for a quarterback sneak by Bart Starr to give the Packers a classic win on their own turf.

How Wind Affects Football

While wind can have a huge impact on fans, it can also affect the game at field level in some stadiums. I’ve watched at field level amazing NFL kickers like David Akers and Robbie Gould check out wind conditions. I’ve had discussions with punters and kickers about how they change the angle of their kicks based on current wind conditions. None of them claim that it gives them a mental block. But they certainly are aware of the wind and it’s role in their success.

The dominant wind over an area can sometimes result in swirling wind patterns inside some stadiums. Swirling winds at MetLife stadium and the way it is constructed has very little effect on wind affecting the game.

But even a little gust of wind at the wrong time can ruin a play. It happened during the Oakland Raiders at Cleveland Browns during 1980 AFC Divisional Playoffs. With a wind chill factor of -36 F, it was fairly clear that the Cleveland Browns would be more comfortable in the frigid winter temperatures than the Oakland Raiders as the two teams met in the 1980 playoffs. The Browns had six wins on the season already where they edged in front in the dying moments of the game.

Trying to do so once more in the AFC Divisional against the Raiders, the Browns pieced together a remarkable 79-yard drive to get in field goal range. The only problem was that it was so cold that the Browns place kicker, Don Cockroft, already botched two attempts.

Browns Coach, Sam Rutigliano, opted for a more aggressive play, calling out the famous “Red Right 88.” Just as it looked like quarterback Brian Sipe would find Ozzie Newsome open in the end zone — an unpredictable opponent— the wind held up the ball and handed the Raiders an easy interception and eventual win.

How Sky Cover and Precipitation Affect Football

While day games in full sun can really create some glare on field for players, it’s rarely a showstopper. It might result in more of a running game until the sun angle changes but its impact is usually dramatically limited. All NFL stadiums also have a North South orientation and so a sun setting in the west is not a major problem.

However, low clouds can change the game when they sink to field level, which is what happened in the Bears v Eagles
1988 NFC Championship, also know as the Fog Bowl.
Mike Ditka’s Chicago Bears hosted Buddy Ryan’s Philadelphia Eagles in the NFC Championship Game, and late in the second quarter, a mist started to set in. It didn’t stop, though, and by the fourth quarter it was a dense fog and visibility dropped to about 10 to 20 yards. Broadcasters were forced out of the press box to field level to call the game. Eagles quarterback Randall Cunningham wasn’t affected as he still managed to throw for 407 yards.
Players could barely see the sidelines or the first down markers, so referee Jim Tunney had to announce each play over the microphone. The Eagles moved the ball well but couldn’t find the end zone enough as the Bears ended up winning 20-12.

If there is a storm during the game, expect that the rain and snow will affect play. When wet weather happened during the
49ers at the Greenback Packers 1996 NFC Divisional, it was cold but not below freezing at Lambeau Field. It was just warm enough that there was the unfortunate mix of rain and snow. The result: A soggy, sloppy and muddy field that made both offenses feel like they were working in quicksand.

The 35-14 score in favor of the Packers wasn’t indicative of how badly the offenses struggled. The Packers passing game was stuck in the muck, finishing with just 79 passing yards. Meanwhile, the 49ers offense totaled just 196 yards but gave away five turnovers thanks to the muddied conditions.

There’s a classic tale of field conditions changing the game from Bears v. NY Giants 1934 NFL Championship Game
The Chicago Bears had won 18 straight games and seemed invincible heading into the 1934 NFL Championship Game. Some force of nature would have to stop them and basically it did.

A freezing rain covered the Polo Grounds, and as the Giants were slipping behind (figuratively and literally), equipment manager Abe Cohen brought in nine pairs of sneakers borrowed from the Manhattan College basketball team.

The Giants made the switch at halftime and never looked back. The sneakers put them on better footing as they outscored the Bears 27-3 in the second half en route to a 30-13 win.

Perhaps the worst weather playoff game in recent history was the Raiders v Patriots Snow Bowl during the e2001 AFC Divisional Playoff With the Oakland Raiders visiting, Tom Brady threw an incomplete forward pass late in the fourth quarter, which resulted in another opportunity for the Patriots to play in overtime and eventually win. The weather was miserable as Foxboro Stadium was covered in a sheet of snow, earning the label of the Snow Bowl from Patriots fans — or the Snow Job from Raiders fans.

Making the Call:
A look a Mother Nature’s Playbook

Climate history tells us that more often than now, the weather is chilly with scattered clouds on early February evenings. And it makes sense to expect a bit of a wind chill during the game. When temperatures drop below 40°F, any wind will cause the apparent temperature to the human skin to feel significantly colder than the actual air temperature. This is common for the NYC area in February.
The exact time of kickoff is 6:28:30 Average temperature at that time is 35 degrees. Looking at climate data over 30 years, between Jan 25 and Feb 3 there is an average of 2inches of snow. THE NJ State Climatology Researchers say over 50 years of weather the temperature range is 19 to 51 degrees.

During the last 13 years the NYC area high temp has ranged from 32 to 50 on Feb. 2nd. There have been both rain and snow showers within two weeks of February 2nd including a recent, monster snow storm of 18 inches Jan 26-27, 2011

On This DATE in NYC Weather History
Feb. 2, 2013 Snow 31 degrees
Feb. 2, 2012 Partly Cloudy 50 degrees
Feb. 2, 2011 Snow 39 degrees
Feb. 2, 2010 Snow 33 degrees
Feb. 2, 2009 Partly Cloudy 53 degrees
Feb. 2, 2008 Partly Cloudy 43 degrees
Feb. 2, 2007 Rain Snow Mix 38 degrees
Feb. 2, 2006 Partly Cloudy 52 degrees

February Overall Extremes
Biggest Blizzard 26.9” 2006
Warmest Feb. Temperature 75 1985
Coldest Feb. Temperature -15 1934
Highest Pressure ever recorded in NYC was Feb 13, 1981 31.08”
Coldest Ever Feb. 9, 1934 -15 degrees
Biggest Storm Feb 11=12 2006 26.9”
Feb 201 Greatest Snow in a month 36.9”
The highest wind gust ever recorded during game time hours on February 2nd was 38 mph in 2001

The Farmers Almanac predicted a blizzard to hit between Feb. 1-3 The Almanac used words like piercing cold and bitterly cold and biting cold to describe early 2014. The 197-year-old publication uses planetary positions, sunspots and lunar cycles to make predictions more than a year in advance. The Farmers Almanac claims its right 80 percent of the time.
NJState Police commissioned a report from David Robinson a climatologist at Rutgers University (he’s been doing this more than 20 years.) Analyzing weather faces for the 1 days leading up to Feb. 2nd. Range of possibilities is listed out on his website

Accuweather is doing a day by day update on

Interesting cold weather games in the NFL

This year the Big Game date is Feb. 2nd but here’s a look at
NYC Weather History on Past Big Game Dates (even though all these games were played in other fair weather cities!)

Feb. 3, 2013 30 degrees Snow
Feb. 5, 2012 40 degrees
Feb. 6, 2011 45 degrees
Feb. 7, 2010 34 degrees
Feb. 1, 2009 51 degrees
Feb. 3, 2008 50 degrees
Feb. 4, 2007 25 degrees
Feb. 5, 2006 55 degrees
Feb. 6 2005 53 degrees

Weather Discussion

Many blogs, websites, forecasters, and hobbyists will be talking weather and stats leading up to game day. But based on forecasting experience, climate data and current weather models it looks like the game will be cold and windy.

Average wind speeds hover around 10 mph in early February, which can create a considerable wind chill with low temperatures. Winds do tend to lessen in early evening which is game time.

Also keep in mind, the weather from NYC to Rutherford NJ can vary, after all they are two different states– even though the two spots are admittedly geographically close. When looking at the official reporting stations in NYC – the game is still actually being played over in NJ! This is an important consideration. For example, when eight inches of snow fell on Philadelphia’s Lincoln Financial Field during the Dec. 8 NFL game between the Eagles and Detroit Lions, “the Meadowlands just got a dusting.” These two locations are also in the same region. Different spots get different weather!

So even though the media is referring to the game location as NYC, consider that it does actually take place across the river in East Rutherford. Here is a breakdown of the record climate data for the two spots where records are kept Central Park and LaGuardia Airport.

Feb.2nd Records NYC
Record High 59 1988
Record Low -3 1881
Record Rain 2.98” 1973
Record Snow 5.0” 1874

Feb 2nd Records LaGuardia 1948-2013
Record High 59 1988
Record Low -1 1955
Record Rain 1.75” 1973
Record Snow 4.3” 1955

The National Football League settled its last championship in New York, on Dec. 30, 1962 which took place at Yankee Stadium. The temperature at kickoff was 13 degrees and TV crews used bonfires to keep warm. More notable, was the game in 1934, the coldest New York winter ever, the title tilt at the Polo Grounds was played after a freezing rain made the field more ice rink than gridiron. But since 1967, winter weather during a Super Bowl has been as rare as snow in San Diego — which actually did see snow that year.

Looking at Climate Data to make a Prediction.

Looking at kickoff time temperature (observation closest to 6:30pm for each February 2nd at Newark Airport) Here’s what we know:
Warmest kickoff time temperature on record was 61° in 1973.
Coldest kickoff temperature recorded was 13° in 1976.
Average temperature at kickoff time on February 2nd is 34°.
90% of the time the historical data shows that kickoff time temperatures fall between 19° and 51° according to the NJ State Climatology Office. They have collected data with interesting statistical information.
From 1931 to 2013 57% of the time the temp was at or below freezing at the time the game would be played.
In years with below freezing temperatures, the average hourly temperature was 25°.
In years when temperatures stayed above freezing the average hourly temperature was 41°.
During those years, 26% of the time there was precipitation. If precipitation falls, there is a 29% climatologically, the probability is that it will be snow
54% of the time the winds are 10-20mph for the average of 1931 to 2013

Looking at Model Data for Predictions

Another forecasting reference is current model data. The National Weather Service long term trend outlooks, updated daily.
8-14 day weather outlook for temps Meteorologist Amy Freeze

Meteorologist Amy Freeze

Meteorologist Amy Freeze

Amy Freeze at Soldier Field
Amy Freeze at Soldier Field

Partly Sunny or Partly Cloudy 

Talking about the weather is not about how you look at life – the cup half empty or the cup half full?   It’s not an optimistic or a pessimistic view of how many clouds are out there… describing details of cloud is not about the forecaster’s mood!  There is a way to be clear when using Partly Sunny versus Partly Cloudy.  For current conditions, I use the terms “Partly Sunny” during the day, and “Partly Cloudy” at night… obviously it will never be Partly Sunny when describing night conditions.  The way sky conditions are described  in the National Weather Service are defined according to specific parameters.

From the National Weather Service Operations Manual, Chapter C-11 under Zone Forecast Guidelines and Procedures:
DAY                         NIGHT/DAY                       SKY                                                                                                                                                                         Cloudy                      Cloudy                                  8/8 opaque clouds
Mostly Cloudy      Mostly Cloudy                   6/8 – 7/8 opaque clouds
Partly Sunny          Partly Cloudy                    3/8 – 5/8 opaque clouds
Mostly Sunny         Mostly Clear                      1/8 – 2/8 opaque clouds
Sunny                         Clear                                     0/8 opaque* clouds* opaque means that an observer can not see through the clouds; the sun, moon , stars, and blue sky are hidden. NWS official observations make these measurements.When talking about “Partly Sunny” and “Partly Cloudy” in future or forecast terms, the definitions can be even more specific.  Instead of the sky description for “right now,” the forecast looks ahead.  To describe how long sky conditions will remain a certain way, certain definitions are used.  Partly Sunny means only part (less than half) of the time period will be sunny. In that same respect, Partly Cloudy means only part of the period will be cloudy. From least cloud cover to most cloud cover when talking about the future sky conditions, the scale is: sunny, mostly sunny, partly cloudy, partly sunny, mostly cloudy, cloudy. Mostly sunny means more sun than clouds, partly sunny means more clouds than sun, and partly cloudy generally means an equal amount of clouds and sun.Because of their “close call” definitions, “Partly Cloudy and Partly Sunny are essentially the same thing,” said David Wert, meteorologist-in-chief at the National Weather Service Office (Blacksburg.) “Both are used for conditions when the average amount of opaque cloud cover ranges from 45 percent to 75 percent. We usually use ‘partly sunny’ for daytime conditions, and ‘partly cloudy’ for nighttime conditions under these situations. It wouldn’t make too much sense to use ‘partly sunny’ for a nighttime condition.”Amy Freeze at Addison Elementary

Amy Freeze at Addison Elementary

Rain or Showers?

Posted: November 30, 2009 in ALL TOPICS, WEATHER WORDS

Rain, Showers, and Precipitation

A question that viewers ask a lot is about the words used for a wet forecast…  When there’s a chance for rain or showers – what’s the difference?  Believe it or not –  a lot!

Rain is precipitation that forms from stratus clouds.  Rain is a condition that is more widespread than showers.  Rain is steady, and is less intense than showers.  Showers form from cumulus clouds, more isolated, short-lived.  Showers affect a smaller area and are often more intense than rain.

Rain can occur in different durations changing the description. 

Brief rain – short, sudden showers or periods of rain.

Intermittent – on and off intervals, not continuous. 

Occasional – irregular, infrequent intervals of precipitation.

Frequent – persistent short intervals, happening regularly and often. 

Periods of precipitation – rain or snow falling most of the time with breaks.

The area or distribution of the rain is also describable in a forecast. 

Isolated – showers separated during a given period of time. 

Few showers – indicated in time, not over an area. 

Local – restricted to a smaller area. 

Patchy – irregularly occurring in an area.

Scattered – not widespread but of greater occurrence than isolated showers.

Amy Freeze Doing the Coin Toss for Chicago Fire

Amy Freeze Doing the Coin Toss for Chicago Fire

50% Chance of Anything

Posted: November 30, 2009 in ALL TOPICS, WEATHER WORDS

Chance,  Possible, and Probability:   Will it rain or Not!?!?

What does it mean if a forecast calls for a 50% chance of rain?   I have always maintained this is a confusing concept and it’s the main reason that I will rarely if ever use a percent chance in a forecast.  Instead I will use terms like slight chance, showers possible, or rain likely to give the viewer better guidance on what to expect.   However, when 50% chance is used it is not describing a flip of the coin probability.  Instead,  it means there is a 50% chance that a given location within a forecast area will receive measurable rain. Technically, this “probability of precipitation” is defined as the likelihood (expressed as a percent) of a measurable amount (at least 0.01 inch) of liquid precipitation during a specified time period at any given point in the forecast area.   

Amy Freeze in Norman, OK

Amy Freeze in Norman, OK by the Dual Pole Research Radar

A 20% chance of showers?  This means that of the last one hundred times that these conditions existed in this area, it rained twenty times.  A 20% chance that part of the area will receive rain.  According to The National Weather Service, Probability of Precipitation, or POP, is defined as the likelihood of occurrence (expressed as a percent) of a precipitation event at any given point in the forecast area.  The equation used to arrive at POP contains a value for “Percent of Areal Coverage,” so the result of the equation produces a number that also expresses the percent of areal coverage.

Here’s a bit more about how % chances calculated:    Computer models also forecast the probability of precipitation (also known as “POP”) for 6 and 12-hour periods, which some forecasters will blindly pass along to the viewer without explanation and can be very confusing to viewers.  While the math behind the POP is complex, the computer model takes into account the amount of moisture at different levels of the atmosphere, whether air is expected to be rising or sinking, and other meteorological factors. 

The National Weather Service says, “The probability of precipitation is the likelihood of measurable precipitation (0.01 inches or greater) for a specified forecast time period, and occurring at any point for which the forecast is valid.  The probability gives the odds of any one place in the area covered by the forecast getting wet, whether it’s from rain or snow.  The 0.01 inches or greater comes from the fact that any less rain or water from melted snow or ice can’t be measured. If the bottom of the rain gauge is wet, but the water isn’t deep enough to measure, that’s called a “trace’ and really doesn’t count.”

When the NWS forecasters assign a precipitation probability, it  shows their confidence in the forecast, how much of the forecast area is likely to have precipitation, and low long the precipitation is expected to last.  The important point is that the odds are for the rain or snow to fall on any place in the area covered by the forecast.  This means, that the probability could be low as 30% but you have hard rain for a few hours. In this case, the forecast isn’t wrong, you’re just one of the unlucky people who happened to be in the small part of the region that got wet that day. Or, if your lawn and garden needed the rain, you were one of the lucky ones. And, your friend a couple of miles away who needs the rain can’t complain about the forecast not working out. Rain did fall on at least one place in the area. 

Regardless of its accuracy, a weather forecast fails if the user does not understand the forecaster’s words!!  The proper interpretation of a 30 percent chance of rain (assuming the forecast verifies perfectly) is that you will have rain on your head three out of ten times that you hear such a forecast.  A couple of scenarios could play out:   the weather forecaster may believe rain will cover 100 percent of the area if the rain arrives, but his/her confidence that it will arrive is only 30 percent. Alternatively, the forecaster might have great confidence that rain will occur, but he/she believes it will be scattered showers affecting only 30 percent of the area. Regardless of the forecaster’s rationale, the meaning for you is always the same: The chance of rain on your head is 30 percent.
Chief Meteorologist Amy Freeze

The Percentage of Probabiliy (POP) can be described in words by forecasters by following these guidelines, if you can see the percentages the definitions might also clear the air:

    10% probability: Slight chance, isolated or none.
    20% probability: Slight chance, isolated
    30-50% probability: Chance,scattered
    60-70% probability:Likely, numerous

If the probability is 80% or above the forecast will be categorical, such as “Rain this afternoon.”

Amy Freeze at Soldier Field

Amy Freeze at Soldier Field Forecasting for the Chicago Bears

Chief Meteorologist Amy Freeze