The Effect of Large Bodies of Water on Weather and Climate

• Large bodies of water like the Great Lakes have a huge influence on weather and climate

• WHY?• Water is a known as a sink• Heats up and cools down

slower than land• In the fall they keep us

warm• In the spring they keep us

cooler

Lake Huron Ice Cover - March 28/15

The Great Lakes effect our weather and climate in FOUR main ways:

1) Temperature2) Wind3) Convectional Precipitation4) Lake Effect Snow

In Spring the Sun warms land faster than water.Warm air rises over land (called thermals) and coolAir sitting over the Lake races in to replace it.This creates cool/cold onshore winds

In late summer and fall, the Lake is still warmer compared the surrounding land. Warm air over the lake rises and air from land races in to replace it. This creates offshore wind

On Shore wind can lead to convectional precipitation (Thunderstorms) in the summer

• Cool moist air is blown off the Lake and onto to land• The moist air then warms over

land• The warm moist air rises, cools

and water vapour condenses forming clouds and precipitation• Cumulonimbus clouds

Lake Effect Snow can be one of the biggest problems/benefits caused by lakes:• In late fall and early winter the

Lakes are still warm (compared to the air)

• Cold fronts crossing the lake pick up moisture easily and it is turned into snow

• The snow can be very heavy and be concentrated in small area

Why is this a problem?What are the benefits of this?

Also known as snow squalls or streamers

Average Annual snowfall in S. Ontario• Barrie 223 cm• Hamilton 118 cm• Huntsville 282 cm• Toronto 121 cm• Kingston 150 cm• Chatham 80 cm• London 194 cm• Sarnia 112cm• Collingwood 275 cm

• Windsor 129 cm• Wiarton 426 cm• Tobermory 410 cm• Orangeville 160 cm• Minden 248 cm• Kincardine 390 cm• Port Stanley 103 cm• Strathroy 180 cm• Guelph 165 cm• Sudbury 263 cm

Lake Effect Snow is influenced by wind direction. Based on the map, what is the prevailing wind directions for the Great Lakes Region?

In order for Sarnia to receive Lake Effect snow, what direction would the wind have to travel?

What would impact the amount of Lake Effect Snow?

ICE!!!!!!

March 2009 March 2014