Reading Assignment
Moran&Morgan Ch5, Ch6 p95-106 Ch7, Ch9
Reader p296-304

Weather map

If 15z, subtract 7 =8am
If 03z, subtract 7=8pm

Cyclone : Low pressure area that is encircled by an isobar.
Trough: Low pressure area that is not completely encircled by an
isobar
Anticyclone: High pressure area that is encircled by an isobar
Ridge: High pressure area that is not completely encircled by an
isobar

Surface Pressure System

- Air flows counterclockwise and inward with respect to low pressure areas
and clockwise and outward with respect to high pressure areas.
- Air flows fastest the greater the pressure difference across an area. (
the closer the isobar)

Pressure System at all levels except the surface

- Air flows parallel to the isobars( or height contours), counterclockwise
around low pressure and clockwise around high pressure.
- Air flows fastest the greater the pressure( or height) difference across
an area ( the closer the isobars or height contours)

Dew point temperature

The temperature at which the condensation of water vapor occur is the dew
point temperature.

Severe Thunderstorm

Definition: a thunderstorm that is violent and life-threatening
(a) Hail 3/4" or larger
(b) Straight line wind of 50 knots (57mph) or greater
(c) Tornado
"Lightening is not included because all thunderstorm produce lightening"

Front

Front is a boundary between warm air and cold air

Cold front has triangles pointing toward which the cold air is moving

Warm front has semi-circles pointing toward which the warm air is moving

Wave cyclone : Cyclone with fronts

Dry line is a dashed line with unfilled semi-circles

Jet Stream: Area that high and low pressure area are close
together
Pressure force: Air moves from high pressure area to low
pressure area

Coriolis Effect

1 deflects all Frictionless moving objects to the right in the Northern
Hemisphere. Examples: air planes, ocean currents, projectiles, the winds.

2 is maximum at the poles and zero at the equator

3 is, for a given time interval and at a given latitude, greater the faster
the speed of the moving object. Example: Over 1 hour interval , a plane
moving 1000mph is deflected more than a ship moving 20 mph.

4 is, for a given speed and at a given latitude, greater the longer the time
interval an object is in motion. Example: a 5 mph ocean current acting over
a month long period is deflected more than a plane moving 400 mph for three
hours.

Coriolis Effect is important in understanding air motion for
- jet streams( circle the globe)
-extra tropical storm systems(500 to 1000 miles diameter)
-hurricanes (500 miles diameter)

Coriolis Effect
- is less important in understanding air motion for thunderstorms (10 to
100 miles diameter)
- is hardly important at all in understanding air motion for tornados (10s
of yards to 1/2 mile in diameter)
- is not important at all in understanding motion of water into a drain