Friday, July 30, 2010

Heat Advisories, Watches and Warnings

Another day, another heat advisory. As of Friday, it was the eighth day in a row a heat advisory was issued for most of Central Georgia. Also on Friday, an "Excessive Heat Watch" was issued for Southern parts of Central Georgia. We've been throwing these advisories and watches and warnings out for a while now, but I can't remember if we've ever explained the differences between the heat related ones. So here we go!

The most common one we've seen this summer is the "Heat Advisory" which is issued within 12 hours of the onset of the following conditions: heat index of at least 105°F but less than 115°F for less than 3 hours per day, or nighttime lows above 80°F for 2 consecutive days. Pretty simple.

The newest one is the "Excessive Heat Watch". It is issued by the National Weather Service when heat indices in excess of 105ºF (41ºC) during the day combined with nighttime low temperatures of 80ºF (27ºC) or higher are forecast to occur for two consecutive days. So it basically means that nighttime temperatures and dew points aren't going to drop enough to provide adequate cooling overnight to those of us without the luxury of an air-conditioner. This can create a dangerous situation because the body isn't able to recoup and recover before the heat of the day kicks in again.

Just like a Tornado Watch and Warning, a watch means it's possible for this type of weather to occur while a warning indicates that the event is already occurring or imminent.

The "Excessive Heat Warning" has one caveat... Even if nighttime temperatures dip below 80, the warning will be issued if the heat index goes over 115. This is because the guidance for an "Excessive Heat Warning" is: An Excessive Heat Warning is issued within 12 hours of the onset of the following criteria: heat index of at least 105°F for more than 3 hours per day for 2 consecutive days, or heat index more than 115°F for any period of time.

Hope this clears up a little confusion for you. Stay safe out there this summer!

Meteorologist Jason Disharoon

Wednesday, July 21, 2010

Dog Days of Summer

Everyone has heard of the "dog days of summer", right?

Blondie & Abbie

This picture describes what we think of the know days of sweltering temperatures where it is so hot that even dogs don't want to be outside! While this description makes perfect sense, the "dog days" actually have nothing to do with hot weather or dogs. Surprising, huh?

The dog days of summer are July 3rd through August 11th, when the Dog Star, Sirius, rises along with or closely with the sun. Some people believe that the combination of the sun and the brightest star is to blame for the scorching temperatures in the middle of the summer, but really it's just the result of the earth's tilt toward the sun.

The Dog Star & Its Tiny Companion

Some proof of this? Here are average highs during the summer months:
June – 89.5°, July – 91.8°, August – 90.5°, September – 85.4°

So you see, July and August are supposed to the hottest part of the summer and that's why it's no big surprise that the "dog days" stuck! Being such a dog lover, I love the term and may just have to use it later this week as temperatures heat up to above normal values!

Tuesday, July 13, 2010

It's Sooooooo Hot...

Well, to say it's been hot lately would be quite an understatement! But, how hot is it? Here are a few of my favorites!

  • Birds have to use potholders to pull worms out of the ground.
  • Potatoes cook underground, so just pull one out and add butter, salt and pepper.
  • It's so hot that I saw two trees fighting over a dog. : )
  • It's so hot, today I saw a chicken lay a fried egg.
  • It's so hot that it makes me want to take off my skin and sit in my bones.
  • Farmers are feeding their chickens crushed ice to keep them from laying hard-boiled eggs.
  • Cows are giving evaporated milk.
  • You discover that it takes only 2 fingers to drive your car.
  • The best parking place is determined by shade instead of distance.
  • Hot water now comes out of both taps.
  • You actually burn your hand opening the car door.
  • You break a sweat the instant you step outside at 7:30 a.m.
Hope you beat the heat...

Chief Meteorologist Ben Jones

Wednesday, July 7, 2010

Pests & Prime Numbers?

Summer brings around lots of fun memories: time at the pool, hanging out with friends, going to the beach. But every thirteen years here in Central Georgia, you can add one more thing to that list. The incessant buzzing of the cicada, a small insect that rears its head in large masses every 13 years. At least we have one more year before the fun begins. The cicadas aren't due to arrive until July and August 2011.

The Day After Tomorrow

But why is it exactly 13 years in-between outbreaks? And why 17 years for their cousins up in New England? While scientists aren't 100% sure, it appears to relate to math. Yes, math. See, both 13 and 17 are prime numbers, numbers that are only divisible by one and itself. It's believed that cicadas only arrive in prime number patterns to avoid predators. Cicadas are small insects that are very low on the food chain and have many natural predators. By appearing so sporadically, they can avoid most of them. Think about it, if cicadas appeared every 12 years instead of 13, they would also have to deal with predators who come around either every 2, 3, 4 or 6 years. There's a high probability that the cicadas would be wiped out. Add just one year and the probability plummets. The odds of running into a predator that comes around every 4 years is 1 in 52, or less than 2%.

So the next time you're sitting in math class (or listening to your child complain about math class) and you wonder, "Why would I ever need to know this?", remember that even the smallest parts of our world, like cicadas, rely on math and its applications to survive.

Thursday, July 1, 2010

July? Already?

Yes, that's right June has come and gone! And there is no denying that it was a hot fact, I'm sweating just thinking about it! Here's a look back at some of the numbers...

  • 24 days with highs in the 90's
  • Only 5 days with highs in the 80's

You are thinking that's not 30 days...but don't forget we hit the century mark for the first time this year on June 15th. We set a new record high for that day beating the old record of 99 set back in 1963. Fortunately the mercury didn't climb up to 100 any other day during the month; however, it did feel like it was in the triple digits most days...gotta love the humidity!

We've had some scorching days...

As far as rain goes, we have gotten 5.73 inches this month. The normal monthly rainfall amount is 3.54 inches, which means we did pretty well with a surplus of 2.19 inches. For the year, we are just over a half inch below normal.

So, what does July hold? Well I'm not a psychic, I'm just a meteorologist, but here is what the long term models are hinting at as we roll through the next 30 days. Temperatures are expected to be above lower 90's plus the humidity isn’t hot enough? It is fair game as to whether we'll have below normal precipitation or above normal precipitation. And as we head through hurricane season, we'll continue to monitor the tropics for any systems that may head toward the Georgia coast.

Meteorologist Sonya Stevens