Humidity
The temperature that if air drops below, condensation (dew) forms on surfaces
What is air pressure?
What is temperature?
A measure of the average kinetic energy of the air.
What are the 4 ingredients for a tornado?
S.L.I.M.
Shear
Lift
Instability
Moisture
How do clouds form?
When the absolute humidity is equal to the air's capacity to hold onto moisture. The temperature of the air is at or below the dew point. Moisture condenses in the atmosphere and forms clouds.
Warmer air can hold MORE or LESS moisture than colder air? Why?
Warm air can hold more moisture than colder air because it has MORE ENERGY to hold onto moisture.
If the air is more dense, what does that mean about temperature and pressure?
How does a thermometer work?
Warmer air temperatures will cause the fluid in the thermometer to expand and rise in the tube and read higher temperature. Colder temperatures will cause the fluid in the thermometer to contract in the tube and read colder temperature.
How is freezing rain different from sleet?
Sleet freezes on the way down and falls as little ice crystals
Cirrus = wispy, Cumulus = puffy/pile, Stratus = layered
What is the relative humidity if the absolute humidity is 30g/m3 and the capacity is 42g/m3?
RH=?
AH=30g/m3
CAP=42g/m3
RH=AH/CAP x 100
RH=(30g/m3/42g/m3) x 100
RH=71.4%
On a isobar map, how can you determine where the greatest wind speeds are and why?
Where the isobar lines are closer together. It represents an area of high winds due to the change in pressure happening over a shorter distance.
Air masses that originate at the poles are called _________ and air masses that originate at the equator are called __________.
Polar air masses.
Tropical air masses
What type of pressure system is associated with storms and what direction do they rotate in the northern hemisphere?
Low pressure systems result in storms that rotate counter clockwise due to the coriolis effect.
What type of cloud is associated with thunderstorms?
Cumulonimbus
If the relative humidity is 90% and the capacity to hold moisture is 10g/m3, what is the absolute humidity?
RH=90%
AH=?
CAP=10g/m3
RH=AH/CAP x 100
AH=CAP x (RH/100)
AH=10g/m3 x (90/100)
AH=9g/m3
What type of weather is associated with high and low pressure systems?
High Pressure = Happy weather, cold air sinking, sunny, clear skies and no precipitation
Low Pressure = Lousy weather, warm air rising, cloudy skies and precipitation
What happens to weather when a warm front moves in?
The warm moist air rises gradually over the more dense colder air. It carries the moisture up to lower temperatures in the upper atmosphere where it condenses below the dew point and forms clouds and lasting precipitation. Lousy weather.
How does hail form?
Low pressure storm systems create updrafts that cause convection currents in the upper atmosphere. When moisture gets pulled upwards below the freezing line it forms a small ball of ice. As it falls below the freezing line it picks up more moisture and adds another layer of ice as it cycles back up below the freezing line again and grows.
What type of clouds are associated with drier surface conditions?
Cirrus clouds. Exist high in the atmosphere so the actual temperature at the surface is much warmer than the dew point which occurs only when conditions at the surface are dry.
How much moisture can the air hold if the relative humidity is 52% and the absolute humidity is 12.4 g/m3?
RH= 52%
AH= 12.4g/m3
CAP= ?
RH=AH/CAP x 100
CAP=AH/(RH/100)
CAP= 12.4g/m3 / (52/100)
CAP=23.8g/m3
Describe winds around a high and low pressure center?
High Pressure: Clockwise rotation, Outward directed winds (Colder air sinking = Happy weather)
Low Pressure: Counter Clockwise rotation, inward directed winds (Warmer air rising = Lousy weather)
What type of weather is the most deadly?
Extreme heat! Kills more people each year than tornados, hurricanes, extreme rainfall etc.
What is shear and how does it occur in the atmosphere?
Draw the diagram from page 646 into your notes.
eBook pg 646