© Copyright, 2015 (PHNO)
 http://newsflash.org

PHNO SCIENCE & INFOTECH NEWS
(Mini Reads followed by Full Reports)

IT'S NOT THE HEAT, IT'S THE HUMIDEX: Seven things you may want to know about 'Humidex'


AUGUST 17 ---The Toronto skyline is seen Monday, Aug. 17, 2015. Environment Canada’s heat warning for southern Ontario is expected to end by Tuesday morning, but that doesn’t mean hot weather will be leaving with it. The heat warning first came into effect Sunday, and carried through Monday as temperatures edged past the 30 C mark for a second straight day. At the Region of Waterloo International Airport, temperatures hovered around the 30 C mark for the entire afternoon, with humidex values peaking at 38. The humidex is a Canadian creation first used in 1965, according to Environment Canada’s website. It combines the temperature and humidity levels into one value that shows the perceived temperature, or how the heat and humidity feels “to the average person.”  Ah, the humidex. The thing that can make a summer day in Toronto go from a hot 31C to feeling like a stifling 39C. The city, and most of Ontario, has been hit with heat warning after heat warning this summer, in part thanks to a value that can make what could be a pleasantly warm day feel like the Sahara instead. But what exactly is the humidex, anyway? READ MORE...

ALSO: World breaks new heat records in July—US scientists


JULY 21, 2015 ---An Indian man pours water on his face during a hot summer day in Hyderabad, India. AP Photo MIAMI, United States—The world broke new heat records in July, marking the hottest month in history and the warmest first seven months of the year since modern record-keeping began in 1880, US authorities said Thursday. The findings by the National Oceanic and Atmospheric Administration showed a troubling trend, as the planet continues to warm due to the burning of fossil fuels, and scientists expect the scorching temperatures to get worse. “The world is warming. It is continuing to warm. That is being shown time and time again in our data,” said Jake Crouch, physical scientist at NOAA’s National Centers for Environmental Information. “Now that we are fairly certain that 2015 will be the warmest year on record, it is time to start looking at what are the impacts of that? What does that mean for people on the ground?” he told reporters. The month’s average temperature across land and sea surfaces worldwide was 61.86 Fahrenheit (16.61 Celsius), marking the hottest July ever. The previous record for July was set in 1998. “This was also the all-time highest monthly temperature in the 1880 to 2015 record,” said NOAA in its monthly climate report. “The first seven months of the year (January to July) were also all-time record warm for the globe,” NOAA said. READ MORE...

ALSO: The Heat Index or Humidex


General concepts Air Concentration Density Dew Evaporation Humidity bufferingDescription English: for humidity-related template; mix images based on Cloud_forest_mount_kinabalu.jpg The heat index (HI) or humiture or humidex (not to be confused with the Canadian humidex) is an index that combines air temperature and relative humidity in an attempt to determine the human-perceived equivalent temperature—how hot it would feel if the humidity were some other value. The result is also known as the "felt air temperature" or "apparent temperature". For example, when the temperature is 32 °C (90 °F) with very high humidity, the heat index can be about 41 °C (106 °F) The human body normally cools itself by perspiration, or sweating. Heat is removed from the body by evaporation of that sweat.  However, high relative humidity reduces the evaporation rate because the higher vapor content of the surrounding air does not allow the maximum amount of evaporation from the body to occur. This results in a lower rate of heat removal from the body, hence the sensation of being overheated. This effect is subjective; its measurement has been based on subjective descriptions of how hot subjects feel for a given temperature and humidity. This results in a heat index that relates one combination of temperature and humidity to another. READ MORE... LARGER CHART VIEW BELOW........

ALSO: PHILIPPINE HEAT INDEX (FROM 'PANAHON TV' @PAG-ASA WEATHER BUREAU

PANAHON.TV is the Philippines’ dedicated content provider that delivers clear and comprehensive weather, climate change and relevant information. We are the weather information delivery experts. PANAHON.TV presents the country’s earliest weather broadcast fresh from the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) Weather and Flood Forecasting Center in Quezon City, Philippines. It broadcasts daily at 5:00 a.m., live on the People’s Television Channel 4, and on live streaming at www.ptv.ph and panahon.tv. The program also gives real time updates on social media channels such as Twitter and Facebook. Panahon is a Filipino word that means both time and weather. PANAHON.TV is produced by UBE Media, Inc., the communications arm of the Lina Group of Companies, in partnership with the Presidential Communications and Operations Office (PCOO), People’s Television (PTV) and PAGASA-DOST. MEET PANAHON-TV TEAM....VIDEO.....


READ FULL MEDIA REPORTS:

7 things you probably didn't know about the Humidex

MANILA
, AUGUST 24, 2015  
(TORONTO STAR) Mon Aug 17 2015 Posted by Jackie Hong, Staff Reporter at 04:34 PM - The humidex is a Canadian creation first used in 1965, according to Environment Canada’s website.

It combines the temperature and humidity levels into one value that shows the perceived temperature, or how the heat and humidity feels “to the average person.”


Sun seekers hit Sugar Beach Monday despite the high humidex rating. Toronto may get a break from the high readings by the end of the week.
DAVID BATEMAN/TORONTO STAR

Ah, the humidex. The thing that can make a summer day in Toronto go from a hot 31C to feeling like a stifling 39C.

The city, and most of Ontario, has been hit with heat warning after heat warning this summer, in part thanks to a value that can make what could be a pleasantly warm day feel like the Sahara instead.

But what exactly is the humidex, anyway?

READ MORE...

A Canadian creation

The humidex is a Canadian creation first used in 1965, according to Environment Canada’s website. It combines the temperature and humidity levels into one value that shows the perceived temperature, or how the heat and humidity feels “to the average person.”

“The key thing for humidex is really related to how the human body cools itself,” Environment Canada warning preparedness meteorologist Geoff Coulson explained.

“So when we exert ourselves on a warm day, we sweat. That sweat stays on our skin as water droplets and as wind flows around our skin, if the air is dry enough, then a fair amount of that sweat will be evaporated off our skin, and it’s that evaporative process that cools the body.

We start to have problems when we’re exerting ourselves to a fair amount on a day where there’s already a lot of moisture in the air.

So as the air blows over our skin, it doesn’t really evaporate all that much of the sweat that’s on our skin, it sort of stays there. And so that doesn’t let us get the relief we would normally get.”

How does it work?

The humidex is broken down into degrees of comfort:

20 to 29: No discomfort
30 to 39: Some discomfort
40 to 45: Great discomfort; avoid exertion
46 and over: Dangerous; possible heat stroke

Who does it apply to?

The humidex is based on how comfortable an adult in good health would feel in a mix of temperature and humidity.

“This is somebody who doesn’t have any underlying medical conditions that may compromise them or makes them suffering more under these high heat-humidity situations,” Coulson said.

“And it also wouldn’t include the elderly or the very young.”

In the case of someone with a health problem or the very young and elderly, they may feel more discomfort at a lower humidex value – at 35, for example, instead of 40.

It’s an eastern thing

Higher humidex values are most often seen in Manitoba, Ontario and Quebec, with the west being spared for the most part from the humidity.

“The Maritimes can get some occasions when the humidex can get into the uncomfortable range, but in terms of when it happens most frequently, that tends to be sort of southern Manitoba, Ontario and into southern Quebec,” Coulson said.

Windsor holds the dubious honour of the “humidex capital of Canada” because it gets the most days where the heat and humidity combine to give values higher than anywhere else in the country. In general, southern Ontario gets it bad: “I’d say sort of Windsor, Sarnia, London, Toronto, eastwards towards the Ottawa Valley, any of those locations can experience those stretches of high heat and humidity that could result in humidex readings of 40 or higher,” Coulson said.

So, what is it not?

“I think where a lot of the confusion comes about is, people tend to think of it as the actual temperature.

But what humidex is meant to be used for is a sort of comfort index,” Coulson said. “It really is this idea of people learning what their own tolerances are, what their own preferences are and behaving accordingly.”

Does anyone else use it?

Not really. Accuweather has a “RealFeel” value which is basically the same thing but also incorporates things like wind and cloud coverage.

In the U.S., there’s something called the heat index or heat factor.

What else you should know:

Again, the humidex doesn’t have to hit 40 for things to get uncomfortable – it varies from person to person.

And even if the humidex is below 40, children and pets should not be left in cars and people who work outside should stay hydrated, get into shade whenever possible, use sunscreen and take frequent breaks.

Toronto may get a break from the humidex by the end of the week. According to Coulson, the agency is predicting a warm and humid Tuesday and Wednesday, but a front should be moving in Thursday that could bring showers, thunderstorms and cooler temperatures.

“It’s really Friday and the weekend we get out of the humidity once and for all…

We are forecasting temperatures around seasonal values or even a little warmer than seasonal values at 26C to 27C, but the humidity value should be much more comfortable,” Coulson said.

And that cooler forecast starts tomorrow, here in Toronto, Friday August 21 all through the weekend.
 


INQUIRER

World breaks new heat records in July—US scientists @inquirerdotnet 09:20 AM August 21st, 2015


An Indian man pours water on his face during a hot summer day in Hyderabad, India. AP Photo

MIAMI, United States—The world broke new heat records in July, marking the hottest month in history and the warmest first seven months of the year since modern record-keeping began in 1880, US authorities said Thursday.

The findings by the National Oceanic and Atmospheric Administration showed a troubling trend, as the planet continues to warm due to the burning of fossil fuels, and scientists expect the scorching temperatures to get worse.

“The world is warming. It is continuing to warm. That is being shown time and time again in our data,” said Jake Crouch, physical scientist at NOAA’s National Centers for Environmental Information.

“Now that we are fairly certain that 2015 will be the warmest year on record, it is time to start looking at what are the impacts of that?

What does that mean for people on the ground?” he told reporters.

The month’s average temperature across land and sea surfaces worldwide was 61.86 Fahrenheit (16.61 Celsius), marking the hottest July ever. The previous record for July was set in 1998.

“This was also the all-time highest monthly temperature in the 1880 to 2015 record,” said NOAA in its monthly climate report.

“The first seven months of the year (January to July) were also all-time record warm for the globe,” NOAA said.

READ MORE...

When scientists looked at temperatures for the year-to-date, they found land and ocean surfaces were 1.53 F (0.85 C) above the 20th century average.

“This was the highest for January to July in the 1880 to 2015 record, surpassing the previous record set in 2010 by 0.16 F (0.09 C).”

Scientists also calculated the rate of temperature increase for July at an average of 1.17 F (0.65 C) per century.

Large parts of the Earth were much warmer than average, including Africa which saw its second hottest July on record.

“Record warmth was also observed across much of northern South America, parts of southern Europe and central Asia, and the far western United States,” said the NOAA report.

Parts of eastern Scandinavia and western Russia, eastern and southern Asia and scattered areas in central and northern North America were cooler than average.


FROM WIKIPEDIA

The Heat Index or Humidex


General concepts Air Concentration Density Dew Evaporation Humidity bufferingDescription English: for humidity-related template; mix images based on Cloud_forest_mount_kinabalu.jpg

The heat index (HI) or humiture or humidex (not to be confused with the Canadian humidex) is an index that combines air temperature and relative humidity in an attempt to determine the human-perceived equivalent temperature—how hot it would feel if the humidity were some other value.

The result is also known as the "felt air temperature" or "apparent temperature".

For example, when the temperature is 32 °C (90 °F) with very high humidity, the heat index can be about 41 °C (106 °F)

The human body normally cools itself by perspiration, or sweating. Heat is removed from the body by evaporation of that sweat.

However, high relative humidity reduces the evaporation rate because the higher vapor content of the surrounding air does not allow the maximum amount of evaporation from the body to occur.

This results in a lower rate of heat removal from the body, hence the sensation of being overheated. This effect is subjective; its measurement has been based on subjective descriptions of how hot subjects feel for a given temperature and humidity.

This results in a heat index that relates one combination of temperature and humidity to another.

READ MORE...

History

The heat index was developed in 1978 by George Winterling as the "humiture" and was adopted by the USA's National Weather Service a year later. It is derived from work carried out by Robert G. Steadman.

Like the wind chill index, the heat index contains assumptions about the human body mass and height, clothing, amount of physical activity, thickness of blood, sunlight and ultraviolet radiation exposure, and the wind speed. Significant deviations from these will result in heat index values which do not accurately reflect the perceived temperature.

In Canada, the similar humidex is used in place of the heat index.

While both the humidex and the heat index are calculated using dew point, the humidex uses a dew point of 45 °F (7 °C) as a base, whereas the heat index uses a dew point base of 57 °F (14 °C).

Further, the heat index uses heat balance equations which account for many variables other than vapor pressure, which is used exclusively in the humidex calculation. A joint committee formed by the United States and Canada to resolve differences has since been disbanded.

The heat index is defined so as to equal the actual air temperature when the partial pressure of water vapor is equal to a baseline value of 1.6 kPa. At standard atmospheric pressure (101.325 kPa), this baseline corresponds to a dew point of 14 °C (57 °F) and a mixing ratio of 0.01 (10 g of water vapor per kilogram of dry air).[2] This corresponds to an air temperature of 25 °C (77 °F) and relative humidity of 50% in the sea-level psychrometric chart.

A given value of relative humidity causes larger increases in the heat index at higher temperatures. For example, at approximately 27 °C (81 °F), the heat index will agree with the actual temperature if the relative humidity is 45%, but at about 43 °C (109 °F), any relative-humidity reading above 17% will make the heat index higher than 43 °C.

The formula described is valid only if the temperature is 27 °C (80 °F) or more, and the relative humidity is 40% or more.

The heat index and humidex figures are based on temperature measurements taken in the shade and not the sun, so extra care must be taken while in the sun. The heat index also does not factor in the effects of wind, which lowers the apparent temperature, unless the air is above body temperature.

Sometimes the heat index and the wind chill are denoted collectively by the single term "apparent temperature", "relative outdoor temperature", or "feels like".

Meteorological considerations

Outdoors in open conditions, as the relative humidity increases, first haze and ultimately a thicker cloud cover develops, reducing the amount of direct sunlight reaching the surface. Thus, there is an inverse relationship between maximum potential temperature and maximum potential relative humidity.

Because of this factor, it was once believed that the highest heat index reading actually attainable anywhere on Earth is approximately 71 °C (160 °F).

However, in Dhahran, Saudi Arabia on July 8, 2003, the dew point was 35 °C (95 °F) while the temperature was 42 °C (108 °F), resulting in a heat index of 78 °C (172 °F).

Table of Heat Index values

This table is from the U.S. National Oceanic and Atmospheric Administration.


PHILIPPINE HEAT INDEX FROM PAG-ASA



PANAHON-TV TEAM

Executive Producer: Donna May Lina-Flavier
Associate Producer- Government Relations : Dr. Gabriel David, PhD
Associate Producer: Sunshine Joy V. Mendoza
Associate Producer(OIC): Krizia Nhel Gayo
Reporters:
Jemmah Amor S. Larrosa
Jesy Lou E. Basco
Rachel Pelayo

 

VIDEO URL: https://youtu.be/wfbm8jPeCrc


Chief News Editor: Sol Jose Vanzi
© Copyright, 2014 by PHILIPPINE HEADLINE NEWS ONLINE
All rights reserved


PHILIPPINE HEADLINE NEWS ONLINE [PHNO] WEBSITE