Grade Level: 3-4 Summary:
Students will forecast the weather using a variety of techniques and instru-
Teaching Methods: Data Collection, ments.
Discovery, Discussion, Graphing, Observation,
Problem Solving, Writing
Preparation Time: 1.5 hours Students will demonstrate weather forecasting skills.
Activity Time: 1.5 hours Students will collect and record weather data.
Students will question the validity of weather folklore.
Clipboards PA Science & Technology Standards:
Pencils 3.1.4. Unifying Themes
Writing paper C. Illustrate patterns that regularly occur and reoccur in nature.
Weather Forecasting Data worksheet E. Recognize change in natural and physical systems.
Thermometers 3.2.4. Inquiry and Design
Barometer (dial face) A. Identify and use the nature of scientific and technological
Daily Journal of Barometer Readings knowledge.
Compass B. Describe objects in the world using the five senses.
Weather vanes 3.5.4 Earth Sciences
Beaufort Wind Scale C. Know basic weather elements.
Heavy stock paper Other PA Standards:
Paper fasteners Mathematics
Weather Forecasting Guide worksheet Reading, Writing, Speaking and Listening
My Weather Forecast worksheet
Activity II Background:
Index cards Weather can be described as the overall effect of what is happening in the
1 copy of Weather Folklore Cards air around us. Weather includes rain, snow, and other types of precipita-
tion, plus humidity, temperature, wind direction, wind speed, cloudiness,
Park Location: Inland, away from beach. and air pressure. All of these factors added together give us the term
“weather.” Weather is constantly changing in all parts of the world. This
Pre/Post Lessons: is due to the earth’s rotation, position of the sun, land formations, and air
Pre-visit: Weather Predictions masses.
Post-visit: Weather Reporters
Over the years, weather forecasting has gone from simple observation to
a modern form that uses technology, science, and advanced math to accu-
rately predict the weather. The gathering of information is always the first
step needed in weather forecasting.
Some of the tools used today to gather information include computers,
radar, satellites, and weather balloons. Twice a day weather balloons are
launched all over the world. These balloons record data such as tempera-
ture, pressure, humidity, and wind speed at different heights in the atmos-
Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, Bureau of State Parks 1
phere. Satellites allow meteorologists to see what the Cirrus clouds are found at the highest level and are
earth and clouds look like from space. Doppler radar formed by ice crystals. They are often referred to as
looks into clouds with radio waves to see how rain or “Mare’s Tails” because of their thin, wispy look. Cirrus
snow is acting and how it might change. All of this infor- clouds are a sign of warm moist air rising up over cold air.
mation is then loaded into computers. The computers put They are sometimes an early signal that thickening clouds
the information on maps, then meteorologists read the could bring light rain or snow within one or two days.
maps and make a weather forecast according to the data
presented. Air Pressure
Barometric pressure, otherwise known as air pressure, is
Many different people forecast the weather such as local directly involved with weather changes. Air pressure is
television meteorologists and scientists at the National the weight of air in our atmosphere pressing down upon
Oceanic Atmospheric Administration (NOAA). Anyone the earth. It can be compared to the weight of water
can be a weather forecaster even if they don’t have techni- pressing down on a person as they dive deep into a pool
cal monitoring equipment available. of water. The weight of the atmosphere decreases as you
go up in the atmosphere. People can feel the effect of air
Clouds pressure as they hike up and down mountains or fly up
One of the easiest ways to forecast the weather is by ob- and down in airplanes.
serving clouds. Clouds give clues about what is happening
in the atmosphere and how the weather might change in A barometer is used to measure air pressure. It indicates
the hours or even days to come. Each type of cloud whether the pressure is rising or falling. A rising barome-
forms in a different way, and each brings its own kind of ter indicates increasing (or high) air pressure and means
weather. sunny and dry conditions. A falling barometer indicates
decreasing (or low) air pressure and means stormy or wet
Clouds are formed when particles of dust, dirt, or salt are conditions.
in the air. Water vapor condenses onto these particles
and rises into the air to make clouds. When air is warmed by the sun, it expands, gets lighter
and rises. In a low pressure center warm, moist air rises
There are three basic types of clouds: Cumulus, Stratus, and favors the development of clouds and precipitation.
and Cirrus. Clouds form at different levels in the atmos- A high pressure center suppresses the upward movement
phere and have a prefix attached to their name that identi- of air that is needed to support the development of clouds
fies the level. High clouds have the prefix “cirro”, middle and precipitation. This is why fair weather is commonly
clouds have the prefix “alto” and low clouds do not have a associated with an area of high pressure.
prefix. If a cloud produces rain or snow it has either
“nimbo” added at the beginning or “nimbus” at the end. Since cold air weighs more than warm air, the pressure of
cold air is greater. Cooler, heavier air blows to where the
Cumulus clouds are the large, billowy clouds that look like warmer and lighter air was, or in other words, wind usu-
heaps of cotton balls. They are as tall as they are wide ally blows from areas of high pressure to areas of low
and are considered low level clouds. They form on sunny pressure. If the high pressure center is very close to the
days from rising pockets of air. Cumulus clouds usually low pressure center, or if the pressure difference (or tem-
signal fair weather, but if they rise to the middle or high perature difference) is very great, the wind can blow very
levels of the atmosphere they become cumulonimbus fast.
clouds. The clouds usually bring severe weather that in-
cludes lightening, thunder, damaging winds, and even tor- Wind Speed
nadoes. Depending on the speed of wind, air masses can frequently
be pushed together causing warm and cold fronts. When
Stratus clouds are layered and cover the sky. They are two fronts collide it can cause severe storms. From Oc-
much wider than they are tall. If the clouds are in puffy or tober through May different air masses often come in con-
broken layers, they are stratocumulus clouds. If they are tact over Lake Erie causing storms. During this period
in high layers that turn the sky solid white, they are cirro- storms can occur one out of every four days. The most
stratus clouds. Cirrostratus clouds are formed by ice violent storms occur in the fall and spring when winds
crystals high in the atmosphere. When stratus clouds are have been measured at over 62 miles per hour. In July,
very thick, they become dark nimbostratus clouds, which average wind speeds at Lake Erie vary from 9 to 14 miles
can produce rain, drizzle, or snow. per hour. In the other three seasons the wind speeds are
higher, averaging 11 to 16 miles per hour. The most com-
Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, Bureau of State Parks 2
mon wind direction is from the south/southwest with the source of the continental polar air mass, you can expect
most severe winds moving from the west at speeds up to temperatures to remain somewhat constant ranging from
45 miles per hour. cool to cold temperatures. Erie is subject to a greater
variation in temperature because it is in a zone that ex-
Wind Direction periences several different air masses.
Wind direction can also predict if there will be a change in
the weather. Wind moving from the south usually brings During winter months, cold air masses moving south from
warm, moist air and wind from the north brings cold, dry Canada are changed by the warm unfrozen waters of the
air. lake. The temperature differences between the water and
the air produce excess moisture in the way of cloudiness
Winds moving from the west are called “westerlies” and and frequent snow from November through March.
these are the winds that move across North America.
Winds from the northwest, west, and southwest tend to During warmer months breezes are produced over the
bring good weather. Winds from the east, southeast, and lake due to the cooler temperature of the water. These
south often bring stormy weather. breezes blow towards land cooling areas 48 to 64 miles
inland. At night the reverse happens and the breezes blow
Temperature from land out over the water, because the land tempera-
Temperature is a measure of heat content. The air tem- ture is cooler than the water.
perature at any place is determined by 1) radiation and
heat transfers between the surface and the air above, 2) In the summer Presque Isle State Park has an average day
the location relative to a large body of water, and 3) the time temperature of 70°F while Lake Erie’s water tem-
movement of vast pools of air called air masses. perature often reaches 77°F. During July and August clear
skies prevail almost 40% of the time and each day averages
The immediate source of energy that heats the air is the more than ten hours of sunshine.
surface of the earth. The sun heats the land and the land
gives off radiation that warms the air. In contrast, during the winter 70% of the lake is frozen
and the average temperature on land is 25°F. Cloudy win-
Clouds have an impact on the radiation balance and air ter skies are present 70% of the time with less than three
temperature of a place. Clouds can block incoming solar hours of sunshine per day.
radiation by reflection off their tops. Clouds also act to
spread out the light as it penetrates towards the surface. In general, accurate weather predictions are not always
Both of these would act to cool the air. In reverse, clouds possible because of the large number of variables involved.
and water vapor absorb the radiation given off by the land No one is ever certain what the exact weather will be at a
and send it back down to the earth, warming the air. The particular time, but careful observation of the environ-
coldest evenings occur during cloudless conditions. When ment can provide clues as to what may happen in the near
days and nights are both cloudless, the earth warms signifi- future.
cantly during the day raising the air temperature but at
night the heat radiation escapes into space dropping the Wacky Weather Facts
temperature significantly. During Fourth of July celebrations in 1918, black
storm clouds covered the sun in the Midwest.
Air temperature is also greatly affected if it is close to a Cold winds and rain forced people inside. The
large body of water such as Lake Erie. Air temperature rain turned to hail, then snow, and didn’t stop for
near or over bodies of water are much different from that three days.
over land due to differences in the way water and land In South Dakota on January 22, 1943, people
cools. Water is transparent and land is not. Water allows probably peeled their extra coats off fast when
light to penetrate deep, leaving the surface layers cooler the temperature jumped almost 50° in 2 minutes!
than they would be if the surface was not transparent. A At 7:30 a.m. the temperature was -2°F, but by
cooler water temperature results in cooler air tempera- 7:32 a.m. it was 44°F.
tures above. Much of the heat on land is transferred into On January 28, 1887, people on the Coleman
the air but on water most of the heat is used for evapora- Ranch at Fort Keogh, Montana saw Frisbee-sized
tion. With little energy used for heat transfer into the air, snowflakes – 15 inches across and 8 inches thick.
the air over water remains cooler than that over land. Dinner for the cats fell from the sky over Aber-
Air masses influence temperature depending on the dare, Glamorgan, Wales, the morning of February
source of the air mass. If you live in Canada which is the 9, 1859. Two kinds of small fish littered the
Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, Bureau of State Parks 3
ground after a shower.
Little Miss Muffet would still be running if she had
been in Hungary in 1922. A rainstorm dropped
On October 5, 1968, inch-long maggots fell from
the sky during a storm in Acapulco, Mexico.
Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, Bureau of State Parks 4