Heat Waves Hot Weather and … HIGH PRESHA!!! ~ WATHER 101 with AL

kaprielianBy: Al KaprielianSept., 2015

It is hard to believe that September is here. The summer seemed to fly by. We are starting September this year on a sunny note. We can still get hot and humid weather in September, and this year is no exception. What causes hot weather and what is a heat wave?

Hot weather is caused by the jet stream, which are winds 20-40,000 feet above the earth’s surface, tracking north of our region. When we are located south of the jet stream, this is known as being on the hot side of the jet stream. What causes the jet stream to track north of our region?

The answer is an upper level ridge of HIGH PRESSURE.

This upper level ridge of high pressure located off the east coast of the United States is referred to as the Bermuda high pressure. It’s position is close to Bermuda, and that is the reason it is given the name Bermuda high. Air circulates clockwise around high pressure. This causes the winds to come out of the south and southwest. A south to southwest wind brings hot, humid air from the southern states of the US and the tropical regions. This is why it is warmer/hotter on the west side of the high-pressure system. To the east of the high is the cooler side because the winds are coming out of the north and northwest. This brings cooler/colder air out of Canada and the northern regions.

However, with the Bermuda high, this gives us hot and humid weather. The upper level high, the Bermuda high this month is quite strong, so we could see the hot & humid weather last for a while.

Also, there may be a lack of clouds with the Bermuda high or high-pressure in general. The reason is that high pressure is caused by sinking air. When the air sinks, this causes the air to compress. That compression of air causes it to heat up. When the air sinks (compresses), we call this subsidence. When subsidence occurs the air is not only warming, but also the air is drying. Clouds have difficulty forming in dry air. As a result you can have a day or days with no clouds at all due to … HIGH PRESSURE!


A heat wave is defined as three or more consecutive days of 90 degrees or higher. The word consecutive is key to getting a heat wave. When a heat wave is in progress, you should drink plenty of water. Also try and refrain from strenuous outdoor activities. Wait until after the sun goes down. Also, wear lightweight clothing (shorts). You should also wear light colored clothing, because light colors absorb less heat from the sun. When there is a heatwave you should always check in on the elderly, especially if they do not have air conditioning.

Lastly, it’s very important that you NOT LEAVE PETS OR CHILDREN IN A VEHICLE WITH THE WINDOWS CLOSED!!! This can be fatal!!!