Download Weather vs. Climate

Let’s get something straight around here.
Weather
 Weather is the sum of all physical properties such as:
temperature, atmospheric pressure, humidity,
precipitation, sunshine, cloud cover, and wind
direction and speed.
 These factors can change from moment to moment
and are more easily identifiable by the general public.
Climate
 Climate is the average long-term weather of an area.
 This includes the general pattern of atmospheric or
weather conditions, seasonal variations, and weather
extremes averaged over a long period (at least 30
years).
 The two main contributing factors include
temperature and precipitation.
Climatic Regions
 Tropical – between 23.5o North and 23.5o South.
 Temperate – from Tropical region to approximately 55o
North and 550 South.
 Polar – from Temperate region to 90o North and 90o
South.
 Climate changes from Equator to Pole is mimicked as
one moves from sea level up in elevation.
Climatic Regions
Air Circulation
Pressure Systems
 High Pressure generally indicates stable, clear weather.
 Low Pressure generally indicates unstable, stormy
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weather.
Winds flow from areas of high to low pressure.
The greater the pressure difference, the stronger the
winds.
Cold air is more dense and will “dive under” warm air.
Moist warm air forced upward will form thunderheads.
Baltimore Climate
 Baltimore, located at 39.2833oN in the mid-Atlantic coastal
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region of North America enjoys a maritime temperate
climate.
Winters are cool, but not frigid. Precipitation the Winter
falls at a steady pace.
Summers are very warm. Precipitation in the Summer is
less frequent than Winter.
Spring and Fall are mild. Precipitation falls mostly in the
Spring.
The proximity of the Atlantic Ocean offers a stabilizing
effect on average annual temperatures.
Why/How?
In a word: Specific Heat
Baltimore Weather
 Who can predict? Certainly not the meteorologists.
 Weather is influenced by many factors (the Great Lakes,
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the western Maryland mountains, the Chesapeake Bay)
but, the Atlantic Ocean drives the weather.
What type of weather would you expect to enjoy on March
17th in Baltimore?
Record High – 85oF
Record Low – 15oF
Average High – 54oF
Average Low – 34oF
Yesterday’s High - 45oF
Yesterdays Low - 38oF
Baltimore Weather
 We are expected to receive a “wintry mix” this
afternoon/evening.
 Why is it unlikely that we will be have a delayed
opening or “snow day” tomorrow?
 Warm periods in recent days have kept the
temperature of the ground above freezing.
 The increasing angle of the Sun means that more solar
radiation is reaching the Northern Hemisphere.