How does a lake breeze form?

WEATHER: Like It or Not!

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Monday, August 19, 2019
How Does a Lake Breeze Form?
Many times you will hear the meteorologists on ABC 7 talk about the lake breeze and how it is impacting our weather. But do you know how the lake breeze forms?

CHICAGO (WLS) -- Many times you will hear the meteorologist on ABC 7 talk about the lake breeze and how it is impacting our weather. But do you know how the lake breeze forms?

It all comes down to a difference in temperatures between the land and the water.

The sun heats the ground. The ground warms up faster than water. This means that the air just above the land will warm more than the air over the water. This temperature difference between the warmer air over the land and the cooler air over the water, sets up the contrast needed to generate the lake breeze.

Warm air wants to rise. As that warm air rises, the cooler, more dense air over the water moves inland to replace the rising warm air. This generates the lake breeze. The cooler air will then continue to move inland, providing cooler temperatures along the lakefront.

Under certain conditions the lake breeze can initiate thunderstorms. This is most likely in the summer.

There are certain conditions that make lake breezes more favorable.

Spring through early fall is usually the time frame when Lake Breezes become most prevalent.

Days with light winds allow the lake breeze to develop. If there is a strong southwest wind here in Chicago, there will be no lake breeze. The southwest winds will keep the cooler air over the water and not allow it to move inland.

Days with lots of sunshine help enhance the temperature difference between the land and water.

Temperatures differences of 20 degrees or more, along with calm winds, really create a good environment for a strong lake breeze.

In the early spring, water temperatures can be in the 30s and temperatures on the land can be in the 40s. This can lead to a lake breeze too. And in April you've felt impacts like that when sitting at a Cubs or White Sox game.

In the summer, air temperatures can be in the 80s but water temperatures only in the 60s. That can create a good lake breeze, helping cool the city and areas along the lake.