Tag Archives: summer

Western Wildfires and Climate Change

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Summer is wildfire season in the American West, and it is off to a raging start. Fueled by prolonged drought and extreme heat, many experts agree that climate change is a significant contributing factor to this year’s widespread fires.

According to NOAA, the past eleven years have all ranked among the warmest on record in terms of global average temperatures. This warming trend, scientists report, is causing an increase in both the frequency and intensity of many dangerous weather phenomena, including forest fires.

This year, hot and dry conditions have dominated much of the United States.  In fact, this summer’s excessive heat follows our country’s warmest spring ever and fourth warmest winter to date.  In the West, these unusually mild conditions did not allow a sizeable snow pack to accumulate in the mountains, reducing spring run-off.  As a result, the region is parched and susceptible to any type of spark.

Warmer winters have also allowed the Rocky Mountain Pine Beetle population to explode and spread to higher elevations.  Feeding on various types of pines, the beetles leave large stands of dead trees in their wake when they move through an area. These ghost forests then essentially act as kindling for potential wildfires.

As of today, nearly forty large fires are burning in ten western states. Despite the arrival of the region’s monsoon season, many of these destructive flames are expected to continue blazing throughout the summer.

Intense wildfires burn across the American West.

Image Credit: KSTP

The Dog Days of Summer

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The “Dog Days” of summer have arrived. This popular saying refers to the hottest and most oppressive days of the season. Varying by latitude around the globe, they traditionally run from July 3rd to August 11th in the United States.

Rooted in astronomy, this non-technical weather phrase is linked to Sirius – the Dog Star.  During most of July and August, Sirius rises and sets with our Sun.  As one of the brightest stars in the night sky, ancient Greeks and Romans believed its conjunction with the Sun added extra heat to the summer months, causing temperatures to soar.  Today, we know that light from this distant star does not affect our weather, but the name has endured.

Aphelion

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The Earth will reach its aphelion today at 11 P.M. Eastern Daylight Time.  This is the point in the planet’s elliptical orbit where it is farthest from the Sun.

Today, the Earth is about 152 million kilometers away from its nearest star.  That is approximately 5 million kilometers further than during the perihelion in early January. The exact date of the aphelion differs from year to year, but it’s usually in early July.

The planet’s distance from the Sun does not cause the seasons, but it does influence their length.  As a function of gravity, the closer the planet is to the Sun, the faster it moves. So, at the aphelion, the Earth will move more slowly along its orbital path than at any other time of the year. As a result, summer is elongated by a few days in the northern hemisphere.

The word, aphelion, is Greek for “away from sun”.

Image Credit: astronomy.edu.au

Weather and Health: Extreme Heat

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An oppressive heat wave is currently scorching the central region of the United States and is forecast to expand eastward this weekend.  As temperatures soar, it is important to remember that intense heat can cause serious health problems.

According to the CDC, extreme heat – temperatures that are significantly hotter than the average local summertime high – is one of the leading causes of weather related deaths in this country.   Claiming hundreds of lives every year, excessive heat kills more people across the U.S. than hurricanes, tornadoes, floods, and earthquakes combined.

Extreme heat is deadly, because it forces the human body beyond its capacity to cool itself. Linked to overheating and dehydration, heat related illnesses range in severity from mild to life threatening.  Symptoms for each stage include:

Heat Cramps:  painful muscle spasms in the legs and/or abdomen

Heat Exhaustion:  fatigue, weakness, clammy skin, and nausea

Heat Stroke:  rapid pulse, hot and dry skin, no sweating, victim could possibly be
unconscious;  a medical emergency

To beat the heat, the American Red Cross suggests:

  • Avoid strenuous activity
  • Dress lightly
  • Eat lightly
  • Drink plenty of water
  • Replenish salts and minerals lost to perspiration
  • Limit caffeine and alcohol
  • Stay out of the sun
  • Cool off in an air-conditioned building, when possible

Early Summer Heat Wave in NYC

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Summer is off to a sizzling start in the eastern United States this year. The season only officially began on Wednesday and extreme heat is already gripping the region.

In New York City, we experienced our first heat wave of the year with three consecutive days of temperatures rising to the mid-90s. The average high for the city at this time of year is 81°F.  In addition to the searing temperatures, the city also had very high humidity levels, creating oppressive conditions.  According to the National Weather Service’s Heat Index, which combines temperature and humidity readings, it felt like we hit the triple digits in the Big Apple this week.

The dramatic increase in heat and humidity in the region is the result of a dominant Bermuda High. This is a subtropical area of high pressure that ushers in hot, humid air from the Gulf of Mexico to the northeast. This sweltering weather pattern, however, is about to change. A cold front is forecast to arrive this weekend, bringing cooler, less humid conditions to the area.