NATS 101 Lecture 3 Climate and Weather 1

NATS 101 Lecture 3 Climate and Weather 1

Climate and Weather “Climate is what you expect. Weather is what you get. ” -Robert A. Heinlein 7

Weather – The state of the atmosphere: for a specific place at a particular time Weather Elements 1) Temperature 2) Pressure 3) Humidity 4) Wind 5) Visibility 6) Clouds 7) Significant Weather 8

Surface Station Model Responsible for boxed parameters Ahrens, p 431 Temperatures Plotted F in U. S. Sea Level Pressure Leading 10 or 9 is not plotted Examples: 1013. 8 plotted as 138 998. 7 plotted as 987 1036. 0 plotted as 360 9

Sky Cover and Weather Symbols Ahrens, p 431 10

Wind Barbs Direction Wind is going towards 65 kts from west Westerly from the West Speed (accumulated) Each flag is 50 knots Each full barb is 10 knots Each half barb is 5 knots Ahrens, p 432 12

SLP pressure Ohio State website temperature dew point cloud cover wind 13

Practice Surface Station 72 58 111 Decimal point What are Temp, Dew Point, SLP, Cloud Cover, Wind Speed and Direction? Ahrens, p 431 Temperate (o. F) Pressure (mb) Last Three Digits (tens, ones, tenths) Dew Point (later) Moisture Wind Barb Direction and Speed Cloud Cover Tenths total coverage 14

Practice Surface Station 42 18 998 Decimal point What are Temp, Dew Point, SLP, Cloud Cover, Wind Speed and Direction? Sea Level Pressure Leading 10 or 9 is not plotted Examples: 1013. 8 plotted as 138 998. 7 plotted as 987 1036. 0 plotted as 360 Ahrens, p 431 15

Surface Map Symbols • Fronts Mark the boundary between different air masses…later Significant weather occurs near fronts Current US Map Ahrens, p 432 16

Upper-Air Model Responsible for boxed parameters Ahrens, p 431 Ahrens, p 427 Conditions at specific pressure level • Wind • Temperature ( C) • Moisture (Later) • Height above MSL • UA 500 mb Analysis 21

Climate - Average weather and range of weather, computed over many years. Whole year (mean annual precipitation for Tucson, 1970 -present) Season (Winter: Dec-Jan-Feb) Month (January rainfall in Tucson) Date (Average, record high and low temperatures for Jan 1 in Tucson) 23

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Climate of Tucson Monthly Averages Individual months can show significant deviations from long-term, monthly means. 26

Average and Record MAX and MIN Temperatures for Date 27

Climate of Tucson Probability of Rain Cool Site: Western Region Climate Center 29

Climate of Tucson Extreme Rainfall Cool Site: Western Region Climate Center 30

Climate of Tucson Snow! Cool Site: Western Region Climate Center 31

Summary • Weather - atmospheric conditions at specific time and place Weather Maps Instantaneous Values • Climate - average weather and the range of extremes compiled over many years Statistical Quantities Expected Values 32

Reading Assignment • Ahrens Pages 25 -30 Problems 2. 1 -2. 4 (2. 1 Chapter 2, Problem 1) • Don’t Forgot the 4”x 6” Index Cards… I’m getting antsy for a pop quiz. You must be lusting for one too! 33