1. Weather Patterns and Maps
Atmospheric Variables at Work

2. Weather Forecasting Synoptic Map:
Weather Maps that show field qualities such as:
1.)Temperature
2.)Air Pressure
3.)Precipitation
4.)Front Systems
5.)Wind Speeds
At a specific time over a large geographic area

3. Isotherms: represent lines of equal temperature on a weather map- in Fahrenheit or Celsius

4. Drawing Isotherms

5. Isobar: represent lines of equal pressure
Measured from sea level on a synoptic map
Varies from 960mb – 1050mb (normal is )

6. Drawing Isobars

7. What is the Coriolis Effect?
Results from the rotation of the Earth
Causes:
Wind
Ocean Currents
And anything traveling on or in them
*To be deflected! The path of travel is affected!
Coriolis Effect

8. The Coriolis Effect on Wind Deflection
Winds are Deflected due to the rotation of the Earth
If Earth were Stationary-Not Quite!   
Missile and Target Example.

9. Wind Deflection and Direction
Northern Hemisphere: Winds are deflected to the RIGHT (they appear to be deflected left if traveling south) Southern Hemisphere: Winds are deflected to the LEFT Weather in 2013 video

10. Travel Path and Deflection:

11. Planetary Wind and Pressure Belts

12. Page 14 ESRT

14. Convection around the globe
Air rises at equator (Low pressure) and sinks at 30˚ N & S (High Pressure)
Air again rises at 60 ˚ N & S in an area of low pressure and sinks at 90˚ N and S (H)
Because air flows from highlow pressure, this creates our typical wind patterns called PREVAILING WINDS

16. Global Perspective: How prevailing winds affect seasonal weather

18. Coriolis Effect On wind and Pressure Systems
High:
Clockwise and out(Anticyclone)
Lo+66w:
Counter-Clockwise and IN (cyclone)
Northern Hemisphere

19. Pressure Systems and Air Flow

20. Question Checkpoint
Using what you just learned, what is the typical direction (called a storm track) that a storm will travel that originates in the central U.S?

21. Cyclone: a low pressure system “L” on a synoptic map
Cyclone: a low pressure system “L” on a synoptic map. This is a zone of convergence at ground level because rising air at the center draws in air L

22. Anticylone: “H” on a synoptic map/center of a high pressure system
Anticylone: “H” on a synoptic map/center of a high pressure system. These are areas of Divergence at ground level where sinking air at the center causes winds to blow outward

23. Air Masses large bodies of air with uniform temperature, pressure and humidity Source Region: Where the air mass comes from
maritime Tropical (mT)- warm & humid air
continental Tropical (cT)- hot & dry air
maritime Polar (mP)- cold & humid air
continental Polar (cP)- cold & dry air
continental Arctic (cA)- very cold & dry air
There are no mA air masses

24. Air mass origins

25. Front Systems represents as a boundary between 2 different air masses
Fronts are named after the air mass BEHIND them and bring about temperature & other weather changes
There are 4 types of fronts: Warm, Cold, Stationary, and Occluded

26. The Cold Front 1.) They pass very quickly!
2.) Forces warmer air to rise, expand, cool & causes rapid cloud formation. This leads to intense precipitation as the front passes
Summer: Cause bad thunderstorms and lightning Winter: Snow storms
4.) Is followed by cooler, drier weather and High Pressure

27. Cold Front

28. Cold Front
warm
cold

29. The Warm Front 1.)Moves Slowly
2.)Warm air flows in to replace a retreating cold air (warmer conditions follow)
3.)Warm moist air rises over cooler air & cools by expansion, which leads toformation of high wispy clouds which thicken over time. Light to moderate precipitation, but steady as the front approaches
4.)Associated with warm, hazy weather followed by LOWER atmospheric pressure after front passes.

30. Warm Front

32. The Occluded Front
Occurs when an advancing cold air mass pushes a lighter warm air mass completely above the ground as it overtakes it mixes
1.)Associated with large areas of rainy, unsettled weather
2.)Once it’s passed the conditions are similar to a cold front

33. Formation of an Occluded Front

34. Occluded Front

35. The Stationary Front
-Occurs when winds blow in opposite directions along a cold and warm air boundary
-little or no movement (a.k.a. stationary)
-clear, partly cloudy or light precip. but nothing severe unless there is a lot of moisture in the air

36. Typical Mid latitude-low storm system Where is it warm and where is it cold?

37. How we predict weather from fronts

39. Jet Stream: upper level winds (tropopause/stratosphere that form where cold, polar air meets warmer tropical air. VERY FAST! Aid in jet travel. Are WESTERLY in U.S.

40. There are two jet streams (high altitude winds moving West East): Polar Jet and Subtropical Jet- They shift position over the year

41. Where the jet stream is positioned brings changes in weather (ex: storms)