1. Weather Ms. Susinno Part 2: Air pressure Weather station model Winds
Air masses and Fronts
Cyclogenesis
Weather maps
Ms. Susinno

2. Air Pressure
EXPLAIN!

4. can be measured in millibars
Air Pressure
can be measured in millibars
Or inches...
Torricelli

5. Air Pressure Centers

6. PRESSURE CENTERS IN THE NORTHERN HEMISPHERE:
Cool
Dense
Diverging
Sinking
Clockwise
igh and dry L
Warm
Less Dense
Converging
Rising
Counter-Clockwise
ow and lousy

7. WIND Most US weather maps use millibars L
ISOBARS – connect points of equal air pressure. L
Where the isobars are close together, there is a great air pressure gradient.
This results in faster/stronger energy flow from High to Low air pressure or
WIND H

8. Find the pressure centers.
Are they H or L? Evidence?

9. Weather Station Model Encoding Air Pressure
Air pressure is normally between 950 and 1050 mb

10. Describe the weather variables at this station:
Draw the Weather Station Model for the station below
Which station (A or B) has the likeliest chance for precipitation?
Provide evidence.

11. How does energy flow? Planetary Winds and Moisture Belts
Jet streams are fast flowing, narrow air currents found in the upper troposphere.
In meteorology, the polar front is the boundary between the polar cell and the Ferrel cell in each hemisphere. At this boundary a sharp gradient in temperature occurs between these two air masses, each at very different temperatures. The polar front arises as a result of cold polar air meeting warm tropical air.
Polar Front Jet Stream H L H L H L H
How does energy flow?

12. Planetary Winds L Winds are named after where they come FROM
The wind system of the Earth’s troposphere exists because of the unequal intensity of solar radiation (because of Earth’s curved surface) and direction to the rotation of the Earth. Coriolis deflects winds to the right in Northern Hemisphere and to the left in the southern Hemisphere.
Winds are named after where they come FROM L
You are here
We live in the Prevailing Southwesterlies
Weather systems and pressure centers are usually pushed from the Southwest to the North East because they are driven by the prevailing southwesterlies

13. US weather systems generally travel from West to East – driven by the Jet streams and the South Westerlies.

14. Local Wind How does energy flow? Warm Less Dense Rising Cool Dense
Sinking
How does energy flow?
Cool
Dense
Sinking
Warm
Less Dense
Rising

15. Local Wind
Winds around High pressure centers and Low pressure centers, and the locations of fronts can change the way local winds blow from day to day L

16. An Air Mass is large volume of air in the troposphere that is mostly uniform in temperature and moisture. Air masses can extend thousands of kilometers across the surface of the Earth, and can reach from ground level to the stratosphere—16 kilometers (10 miles) into the atmosphere.

17. Front the leading edge of an air mass.

18. Air mass = army behind the front Warm Air mass
FRONT= Drummer and Flag people
Warm Front

19. cP mT

20. Warm Front A

21. Cold Front B

22. Describe each front:

23. CYCLOGENISIS-
The development of a mid-latitude cyclone (Low pressure center -storm)

26. 4

27. NEXT UP: WICKED WEATHER Thunderstorms, Hurricanes Tornadoes
And Storm Safety!