I know you're probably thinking it's been hot. But, this time I'm talking really hot. Actual air temperatures this week will reach between 98 and 100. The heat index or feels like temperature may reach 110. This is the kind of heat that can kill if we don't take care of ourselves. You know the drill - make sure you take plenty of breaks and drink lots of fluids - particularly water.
Why is it going to be so hot? The answer is pretty easy. The ridge of high pressure that has been dominating the central United States is migrating Eastward.
This is an incredibly strong ridge of high pressure. With this high - we can expect temperatures 10-12 degrees above average and very hazy conditions. Air quality will likely be an issue this week. There will be little chance for rain until maybe Friday.
One the most common questions I hear from viewers is why don't you talk about the humidity? You always talk about the dewpoint. Here's the reason I don't. Realitive humidity is a terrible measure of atmospheric moisture. You might be surprised that on some of the steamiest afternoons the RH or relative humidity is less than 60-percent. That's because the hotter the air the more capacity the air has to hold moisture. When air cools at night - the relative humidity actually increases quite a bit. That's because cooler air has less capacity to hold moisture. This is why it's referred to as relative humidity. It is realitive to the temperature.
So what is dewpoint and why is it so good? The dewpoint temperature is the temperature in which water will condense out of the air. If the dewpoint temperature is over 65 degrees - it starts to feel a bit sticky. If it's over 75 degree - it's downright uncomfortable. This is a much better measure of comfort factor because it's not temperature dependant.
The dewpoints have been incredibly high as of late. That's why you've noticed your car windows fogging up so easily. With the dewpoint temperature so high (mid to upper 70s) - it's very easy for your car air conditioner to drop the inside temperature and your windshielf temperature to the dewpoint. The only real good way to clear those fogged windshields is to open all of your windows to equalize the temperature inside and outside the vehicle.
Try your best to stay cool this week. It's going to be a challenge for all of us. We'll continue to monitor the tropics - Emily will be forming soon. The models continue to indicate a sharp turn to the north over the next few days. Florida and the eastern seaboard will have to pay close attention to this one.
Have a great week!
Fox 6 Chief Meteorologist