FORECASTING

WEATHER

How do you predict the future?

8.10B identify how global patterns of atmospheric movement influence local weather using maps that show high and low pressures and fronts

WATCH THIS WEATHER FORECAST

If clicking on the picture

doesn’t launch the

video, look for the link

below these notes on

the teacher website –

called “Explaining a

weather forecast”.

Weather maps

are made

from

information

(data)

gathered from

weather tools

INTRO TO WEATHER MAPS -

Look a the map and look at

the lines around the high

and low pressure systems.

An area of high pressure

(H) is a place where cool,

dense air is falling.

An area of low pressure (L)

is a place where warm, less

dense air is rising.

Pressure differences cause

air to move.

LET’S EXAMINE WEATHER TOOLS

AND WEATHER SYMBOLS

Weather forecasting is the analysis of scientific

data to predict future weather conditions

Meteorology – the study of weather and Earth’s

atmosphere

WEATHER TOOLS

Thermometer – temperature

A barometer measures air pressure. It tells you

whether or not the pressure is rising or falling.

An anemometer measures wind speed. The

cups catch the wind, turning a dial attached

to the instrument. The dial shows the wind

speed. (you used one the other day!)

WEATHER TOOLS

A HYGROMETER measures the water

vapor content of air or the humidity.

WEATHER SATELLITES are used to

photograph and track large-scale

air movements. Then meteorologists

compile and analyze the data with

the help of computers.

WEATHER MAP SYMBOLS:FRONTS AND PRESSURES

High Pressure –

Low Pressure –

Cold Front -

Warm Front –

Stationary Front –

Occluded Front -

Make sure you

have these in your

notes!

Weather Map Symbols: Isobars1. Isobars are lines on a map that connect areas of equalatmospheric pressure – the units are in millibars (ex. 1000 mb)

2. The highest wind speeds are found where the isobars on a weather map are spaced closesttogether

Weather Map Symbols: Isobars3. The isobars show air pressure changes over an area

4. The closer the isobars = higher the wind speeds

5. The farther the isobars = slower the winds speeds

WINDS AND AIR PRESSURE

wind patterns - when

temperature increases,

pressure decreases;

when temperature

decreases, pressure

increases;

the result is convection

currents which cause wind

WHAT IS THE JET STREAM?The jet stream is a “river” of air with excessive speeds up to

200+ miles per hour. Weather systems caught in it are

steered by it.

the location and speed of the jet streams changes along

with the season.

High and low pressure systems are “pushed around” by this

stronger stream of air

THE JET STREAM -During the winter, storms are pushed south, the polar jet

stream brings cold air from the polar regions further south

During the summer, the subtropical jet stream is formed from

warm air masses and has less of an impact on the weather

STATION MODELS

A station model is a set of

meteorological symbols that

represent weather at a station.

Placing station models on a

map makes is possible to see

large weather patterns.

WEATHER MAP SYMBOLS:CLOUD COVER AND WIND

WIND DIRECTION

Winds are named for the direction that they come FROM

Wind direction is shown as the arrow extending from the circle (that shows cloud cover) toward the direction from which the wind is blowing.

Here is an example…

The symbol highlighted in

yellow (in the diagram) is

known as a "Wind Barb". The

wind barb indicates the

wind direction and wind

speed.

Wind barbs point in the

direction "from" which the

wind is blowing. In the

diagram, the orientation of

the wind barb indicates

winds from the Northeast.

Westerly Wind

WIND SPEED -

The wind speed is

plotted as feathers

(lines) and half-feathers

(half-lines) representing

10 and 5 knots, on the

barb on the wind

direction arrow.

WIND SYMBOLS: SPEED

Calm

Less than 5kts

5 kts

10 kts

50 kts

NOW YOU TRY IT…

15kts

45kts

25kts20kts

30kts

40kts

35kts

PRECIPITATION SYMBOLS

RECAP ON WEATHER

FORECASTING

Link: https://www.youtube.com/watch?v=FdaD-a53sio

Weather Forecasts

WEATHER MAP PRACTICE STATIONS

You will move from station to station to answer

the questions on your page

Behavior expectation – act with integrity to

complete the work – you have today only!

Keep these notes and stations work – you will

need them for the activity next class.

STATIONS

Station A – Air Pressure and Fronts (Parts I-III)

Station B – Weather Maps A and B (answer questions)

Station C – Weather Maps – forecast practice/weather conditions (2 different maps and questions)

Station D – videos and questions (if you don’t finish the videos, complete this one at home)

Station E – Weather Symbols (matching and chart)

Note – there are keys to these stations, IF you get finished, you may check your work against the keys ☺. You must show the completed work to the teacher first!