6-4.5 Weather Tools and Predictions.pptx

Weather Tools and Predictions

6.E.2B: The complex patterns of changes and movement

of water in the atmosphere determined by winds,

landforms, ocean temperatures and currents, and

convection are major determinants of local weather

patterns and climate. Technology has enhanced our

ability to measure and predict weather patterns.

6.E.2B.1: Analyze and interpret data from weather

conditions (including wind speed and direction, air

temperature, humidity, cloud types, and air pressure),

Assessment Guidelines

•

_{Analyze and interpret data about wind,}

temperature, humidity, cloud types, and air

pressure from weather maps, satellites, and

radar to make predictions related to weather.

– _{1) Using weather symbols to interpret a weather}

map, station model, or hurricane tracking map, and then predict future weather conditions

– _{2) Comparing a series of weather maps to provide}

Why Collect Weather Data?

•

_{Tracking hazardous}

conditions and storms

•

_{Advising the public for}

safety

Wind Speed

•

_{Wind speed: Indicates change in atmospheric flow}

patterns

•

_Tool:

_ANEMOMETER

•

_{SI Unit:}

_{knots, other units: mph}

– _{1 knot = 20 feet/sec = just over 1 mph}

Cup Anemometer Propeller Anemometer

Anemometer-

Wind Direction

•

_{Wind Direction: indicates the direction of}

advancing air masses.

•

_Tools:

_{WEATHER VANE, WIND SOCK}

– _{The force of the wind hits the large surface}

of the vane or sock and rotates it so that the wind has less resistance against it. The

overall effect is that it points in direction the wind originated (came from).

Air Temperature

•

_{Temperature: changes in the air masses result in}

changes in temperature

•

_Tool:

_THERMOMETER

– _{The thermal energy in the air excites fluid or metal in the}

thermometer and makes it expand, or thermal energy is given off and it contracts.

Humidity

•

_{Humidity: is the measure of the percentage of water}

vapor in the air. Increased levels of humidity can be

associated with a high probability of precipitation.

•

_Tools:

_{SLING PSYCHROMETER, HYGROMETER}

•

_{There are two main types of humidity:}

– _{Absolute Humidity-}

The total amount of water vapor in the air. – _Relative

Measuring Humidity

• _{Absolute Humidity- Measured using a Mechanical Hygrometer. It}

works by using an organic material (such as human hair, paper, or bone) connected to a needle that moves as the material expands with moisture or contracts due to lack of moisture.

• _{Relative Humidity- Measured using a Wet Bulb (Sling)}

Psychrometer (psychro- Greek for cold). It works by placing two thermometers side by side and putting a wet piece of cotton on one of them.

– _{As the device is swung around, the wet thermometer evaporates}

faster in a dry environment

– _{The dry thermometer evaporates slower in a moist environment.} – _{The difference in evaporation rates mean a difference in}

temperatures. (think sweat)

– _{Relative humidity is figured by comparing the difference between}

Humidity Cont.

Hygrometer

Sling

Psychrometer-https://www.youtube.com/watch?v=mB9VTmQ5V4o

(0:46)

Rainfall Measurement

•

_{Rain Measurement: measures the volume of}

rain collected in a 24 hour period.

•

_Tool:

_{Rain Gauge}

Air Pressure

• _{Air Pressure: pressure exerted by} the weight of air on the atmosphere • _{Tool: BAROMETER}

– _{Setting Hand (short and may be thicker) is used}

to compare with the Measuring Hand (longer,

may be thinner). The Setting Hand shows what the pressure was set to in the past, while the longer measuring hand shows the current

pressure. You can use this to predict how the weather may change with a change in air pressure.

• _{SI Unit: millibars (mb), Pascal (Pa)}

• _{Other Units: millimeters of mercury (mmHg), inches of mercury} (inHg), pounds per square inch (psi), atmosphere (atm)

• _{Hg = element symbol for Mercury}

• _{The average air pressure at sea level is considered to be}

1 atmosphere (atm).

Air Pressure

•

_{Air Pressure is measured with a barometer.}

M er cu ry B ar o m et er

• _{A barometer rises and falls inside a glass tube w/ a scale printed on it.} • _{The top of the tube is sealed and contains a vacuum.}

-(remember inverted cup demonstration)

• _{As the air pressure increases, the molecules push on the surface of}

the liquid (mercury) and push it up the tube (Higher Pressure).

• _{As the air pressure drops, the liquid becomes heavier than the air}

Setting Hand-

shorter

Combinations

•

_{Weather Stations:}

– _{Most modern weather instruments have been}

Checking for Understanding

Measured

Instrument

Unit(s)

Wind Speed a. b.

c. Barometer d.

e. f. Cardinal directions _{(N, E, S, W)}

g. h. Percent % _{Water Vapor}

i. Thermometer j.

Rainfall k. Inches/cm/mL

Weather Vane/ Windsock

Hygrometer/Sling Psychrometer Humidity

o_F, o_C

Temperature Rain Gauge Knots Anemometer Air Pressure Wind Direction

Checking for Understanding

What instrument would you most likely use to

measure the following scenarios?

1.

2.

3.

4.

5.

6.

Barometer

Rain Gauge Thermometer

Hygrometer _Anemometer

7.

8.

9.

10.

11.

12.

Anemometer Thermometer

Hygrometer/sling psychrometer Barometer

inHg inHg

•

_{Setting hand-}

blue and short

•

_Measuring

Hand-

red and long

4) How is the

weather going to

change?

(increasing/decreasing)

More clear and fair

inHg inHg

(increasing/decreasing)

4)How is the

weather going to

change?

Cloudy, higher chance of rain

What is the direction the wind is coming from

indicated by the weather vane arrow shown?

From NNE, toward SSW From West, toward

This tool is called a rain gauge/graduated cylinder that

measures ________________ in units of mL.

Measure the temperature.

3. _____ F _____ C 2. _____ F

1. _____ C

15

36

32

0

How is this significant?

Humidity

•

_Absolute

Humidity

– _{The amount}

of water

vapor in the air

•

_{Relative Humidity}

– _{Measure of the amount of moisture held in the air}

compared with the amount it can hold at a given temperature.

– _{Can range from 0%-100%}

– _{EX: relative humidity of 50% means the air contains 50%}

What is relative humidity?

A. how much actual water vapor is in the air compared to how much the air can contain at a given temperature

B. how much rainfall a certain climate experiences over a time period

C. how quickly the temperature rises during a certain time period D. how many rainy days occur compared to dry days in a region over a given time period

How is relative humidity expressed ? A. g water per m3

B. m3 _{water per g}

1. A. What is the temperature of the dry-bulb?

B. What is the temperature of the wet- bulb?

2. Using the chart, what is the relative humidity?

24⁰C

20⁰C

69%

Weather Data Collection

•

_{Direct observations and}

measurements

•

_{Weather maps}

•

_Satellites

Direct Observations and Measurements

from meteorologists at national weather data collection sites.

– Weather Balloons (unmanned) in the troposphere and stratosphere collect data

• _{In order to make weather predictions, the data should be collected on a}

regular basis over a period of time.

• _{This allows for the development of patterns in weather conditions from the} analysis of the data.

– _{For example, a hurricane’s path can be predicted using data on its} position over time (plotted on a hurricane tracking map), thereby allowing meteorologists to make predictions concerning the possible warnings to land areas in the hurricane’s path.

• _{Watches: conditions are favorable for weather event to}

happen [Be prepared]

• _{Warning: weather event is being observed or highly}

Weather Maps

• Weather maps can help predict weather patterns by indicating:

– _{High and low pressure systems}

• _{Isobars: lines with equal pressure}

– _{The closer the windier}

– _{movement of air masses and fronts} – temperature ranges

• _{Isotherms: lines of equal temperature}

• Station models from specific locations provide information that can also be used to predict weather patterns. Information found on a station model can include:

– _{cloud cover,}

– _{temperature (85⁰F),}

– _{wind direction and speed,}

– precipitation (* - snow, ● – rain), or

– _{barometric pressure (1002 mb).}

USAA weather map

•

_{Check out today!}

Satellites

•

_{Where? Thermo- and Exosphere}

•

_{Satellite images are used for}

_{seeing cloud}

patterns and movements.

– _{For example, hurricane clouds and movement can}

Hurricane Arthur

•

_{Infrared satellite}

(detects heat)

– _{Cooler colors indicate}

low-topped, warm

clouds (or the surface itself), and the

warmer colors

Radar

•

_{Radar images can be used to}

detect

cloud cover, rainfall or

storm location, intensity, and

movement, as well as the

potential for severe weather

1. If you wanted to analyze rainfall and precipitation intensity, you should use data from

_________________________________.

2. Most of Earth’s incoming ultraviolet radiation is absorbed by __.

A. clouds B. dust C. ozone

D. water vapor

Station Model

.

Anatomy of a Station Model

Temperature

Barometric

_Pressure

(1017.2 mb)

Precipitation

Type

Amount of

Cloud Cover

Wind Direction

and Speed

(points where wind is coming from)

1. _2.

3. _4.

1.______

2. ______

•

_{A knot equals}

•

_{1.85km/hr or 1.2 mph}

(half flag) (full flag)

A knot equals

1.85km/hr or 1.2 mph

Wind is blowing FROM the West at 75 knots

From NE at 25 kts

1. What is the temp in ⁰F? a. 35 b. 38 c. 52

2. What is the pressure in millibars (mb)?

a. 38 b. 52 c. 103.5 d. 1003.5 3. What kind of clouds?

4. What direction is the wind coming from?_____ going? __ 5. How fast is the wind?

6. What kind of precipitation?

overcast

E

W

25 kts

1.Cloud cover:

2.Wind Speeds (knots)

3.Wind Direction

4.Pressure (mb)

5.Temp (F)

6.Precipitation

from the S

1000.3 mb

64⁰F

2. Label the high pressure system with a large blue H and low with a large red L. 3. Color the high pressure system area yellow and low pressure system green.

H

H

1. Connect lines of constant temperature (isotherms) 2. Draw the front boundary.

1. Where are the high pressure systems are located? (A B C D) 2. Where is the low pressure system located? (A B C D)

3. What is the weather like for H? L?

C

D

A

1. Where are the high pressure systems are located? (A B C D) 2. Where is the low pressure system located? (A B C D)

3. What is the weather like for H? L?

C

D

A

1. As a cold front passes over an area, the weather is usually __.

A. cool and clear. B. overcast and stormy C. warm and clear

2. AFTER a cold front passes over an area, the weather will likely be __.

A. cool, clear, and windy. B. overcast and stormy. C. warm and humid.

3. A line of constant pressure is called a(n) __________________________. 4. A line of constant temperature is called a(n) _______________________. 5. When looking at the isobars on a weather map, which statement is

correct?

A. It is windiest when the isobars are close together. B. It is windiest when the isobars are far apart.

C. The numbers on the isobar lines tell you the wind speed in knots.

6. A combination of symbols that shows the weather conditions at a specific location on Earth’s surface is __.

A. Weather map B. Station model C. Radar

7. A device that orbits the Earth and detects cloud cover and other weather parameters is __.

A. Weather satellite B. Station model C. Radar

isobar