meteorology 2 Flashcards
how is the data measured
surface measurements
weather balloons
how often do they gather weather data
every 6 hours
taken in degrees and dew point
taken in the shade
no wind
6feet above grass
temp and dew point
usually in millibars pressure is abbreviated 1013.2 on the model becomes 132 998.2 on the model becomes 982can also be in inches of mercury 29.92 is sea level
pressure
large chunk of air that acquires characteristics of location
temp
moisture
air masses
warm
tropical
cold
polar
dry
continental
moist
maritime
boundary between 2 different air masses
air masses collide and the weather can change dramatically
fronts are always attached to low pressure, never high pressure
front
types of fronts
cold fronts
warm fronts
stationary
pressure rises temp drops winds shift to the north rain cumulonimbus clouds
cold fronts
pressure drops temp increases winds shift to the south rain is produced Stratiform clouds cirrus, altostratus, stratus and nimbostratus
warm front
neither cold nor warm air is advancing
soaking rains produced
nimbostratus clouds
stationary front
show the pressures across the country by using isobars
show the pressure
usually in inches or millibars
every point along isobars the exact same pressure
pressure maps
the change in pressure between isobar lines
common interval is 4 or 5 millibars or .10 inches
isobars never cross or touch
isobars interval
clear skies above the high pressure
winds move in a clockwise direction
cool air is sinking from upper atmosphere
pressure values decrease away from pressure center
no fronts
high pressure
an educated prediction of the future weather
based on observation
climate
General trends
our weather systems move from west to east
move about 1/3 of US in 24 hours
forecast
cloudy skies
warmer temps
lower pressures
winds rotate counter-clockwise
low pressure
clear skies
lower temps
higher pressure
winds rotate clockwise
high pressure
rain cloudy skies warmer temps lower pressure higher dew points south winds
warm fronts
typical cyclone
area of very Low pressure
winds rotate in a counter clockwise direction
originate off the west coast of Africa as thunderstorms
hurricane
over warm water - typical 80° high humidity low wind shear rain bands eye wall eye
formation
wind moving in different directions
wind shear
when is storm season in the Atlantic
June 1st- November 30th
produce rain during hurricane
rain bands
the fastest winds, surrounds eye
eye wall
2 types of cyclones
tropical depression
tropical storm
74-95 mph
category 1
96-110 mph
category 2
111-130 mph
category 3
131-155 mph
category 4
156 and up
category 5
how wide across can hurricanes be
1000 miles
where do the US hurricanes start
the west coast of Africa
why are there no hurricanes in California
water is too cold
thunderstorms off the coast of Africa tropical wave disturbance in the atmosphere intensify over warm water rising air condenses producing additional winds
hurricane origin
low pressure is pushed by south east trade winds
move east to west
can intensify or weaken
depends upon surface water temp
hurricane path
main components of hurricane
eye wall
rain bands
fastest sustained winds
eye wall
flood of water on land
caused by low pressure
enhanced by high winds
right side of hurricane produces highest amount
Storm surge
trees, buildings and cars can be damaged)
high winds
Storm surge
rain
the most damaging component of the hurricane
wide spread
flooding
watches and warnings
evacuation
walls that prevent flooding
levees
cumulonimbus clouds
must have lightning and thunder
severe/ strong storms have hail, high wind speeds, tornadoes
thunderstorms
form when a cold air mass collides with a warm air mass
cold front
cold air causes the warm air to rise quickly forming cumulonimbus clouds
can last for several hours
frontal storms
single storm and no fronts
air parcel rises because it is warmer than the surrounding air
air mass thunderstorms
water falling to earth
condensation nuclei “dust”
precipitation
super cooled water evaporates
deposited onto ice crystals
cold cloud/ ice process
discharge of electricity
balances out the large difference in charges that forms during a thunderstorm
lightning
cloud to cloud
most common
cloud to ground
common
ground to cloud
least common
what do weather maps show
temp dew point Sky/clouds wind speed and direction pressure current weather
strong low pressure system
cold front and warm front
strong thunderstorms
wall cloud
tornado formation
area which has the right conditions to create tornadoes
located between cold front and warm front
larkos triangle
based on damage assessment
correlates to wind speed
EF0-EF5
EF6 is theoretically possible
enhanced Fujita scale
EF0
light
EF1
moderate
EF2
considerable
EF3
severe
EF4
devastating
EF5
incredible
what percent of tornadoes are weak
74%
what percent of deaths are caused by F4 and F5 tornadoes
67%
tornadoes that form on water
water spout
not a tornado
damage is not in a circular motion glide a tornado might be
microburst
conditions are right for a tornado
people are warned that they are in the path of a storm
larkos triangle
start preparing to take shelter
tornado watch
a wall cloud has been spotted
a tornado has been seek
seek immediate shelter
tornado warning