Exam 4 Flashcards
In the Summer, in the northern hemisphere, pressure is _______ over ocean Areas.
Higher
In the Summer in the Northern Hemisphere, pressure is ______ over land.
Lower
In the Winter, in the northern hemisphere, pressure is _______ over land.
Higher
In the winter, in the northern hemisphere, Pressure is ___ over ocean areas.
Lower
Jet Streams
Strong Mainly upper level tropospheric steering winds
River of wind
Stronger in the middle; couple hundred miles wide and only a few thousand feet thick
Polar Jet stream
Steers cold air away from poles
Polar Jet Strams are most active in the _____ and absent in the ____.
Winter; Summer
Polar Jet streams are best found at _______.
300 mb height / 30,000ASL
Subtropical Jet Streams are best found at _______.
200 mb height / 38,500 ASL
Subtropical Jet Strams
get heat out of subtropical regions and shifts it towards polar regions
Low Level jet streams
can break up low level clouds
Low Level jet streams are best found at
850-700 mb height/ 4,000-9,800 ASL
Upwelling
When parallel winds blow surface water off of coast causing colder, nutrient water to come up and replace original surface water
La Nina
Colder than average equatorial pacific ocean water temperature
El Nino
Warmer than average equatorial pacific ocean water temperature
Sea Breeze (daytime)
Upper convection over land
Cloud développement over land
Land Breeze ( Night time)
warmer air over water/cooler over land
clouds over water
Mountain/valley breeze are important when…
fighting fires.
Valley Breeze (daytime)
clouds over peaks/sinks in middle
Mountain Breeze (night time)
clouds over valley/ clear over peaks
Monsoon
a seasonal wind shift in India/southeastern Asia
thermal lows
a low pressure circulation created by changes in air temperature (strong destine) heating over the southwestern USA during the summer months
Katabatic Winds
Cold, downslope winds
Chinook Winds
warm, downslope winds
Katabatic winds are found in …
GReenland, antartica
Chinook Winds are found in …
Eastern Slopes Rockies in USA /Canada
Santa ana Winds
warm, dry downslope winds in California
Santan Ana winds are most common in _____ months
fall
Eddy
localized gusts of wind
EX: wind blowing around the UT tower
Winds Sheer
A rapid change in wind speed and/or direction in a short period of time
(EX: thunderstorm)
Haboob
sandstorm in North Africa/ Inda
Air mass
a mass of air characterized by homogeneous physical properties
(temperature, humidity, moisture)
a or cA / continental Arctic
comes from Antarctica
cP / continental Polar
comes from Canada
-Most predominant in fall because the lakes freeze int he winter
mP / Maritime Polar
Originates over water
-Fog, chilly, wet
mT / Maritime Tropical
warm and humid air mass
- present most of the year
Front
a boundary between two air masses
frontolysis
how front dies
Frontegenesis
how a front develops
overrunning
a less dense air mass overruns a more dense one
When does overrunning happen
when air close to the ground is dense and cold
to be called a front, you need a forward motion of
4-5 mph
cold fronts
when cold air actively advances into a region formerly occupied by warmer air
Blue arrows on a cold front always point…
in the direction they’re going
cold fronts produce _____ weather
more sever
Warm Front
when the surface position of a front moves such that warmer air occupies territory formerly occupied by colder air
warm front slope
1:150
cold front slope
1:50
stationary front
little forward movement oh wither air mass
stationary fronts have been correlated to ….
flash floods
Occuleded Front
when a cold front overruns a warm front in the vicinity of a surface low
the dry line
a boundary between CT (hot dry air and mT (warm moist air) air mass
Whether forecasting is ….
predicting how the state of the atmosphere will change with time
Geostationary satellite imagery
1) visible imagery
- not available in nighttime hours
2) infrared imagery
- able to decipher cloud top temperatures
3) water vapor imagery
- shows atmospheric pressure
Radars show_____
Precipitation
- the larger/ heavier the rain, the redder it gets
Radar reflectivity
how much energy you send out and how much you get returned
Radial Velocity
motion toward/ away form you
Surface weather observations are taken…
at thousands of locations around the world on an hourly basis
observations can be
1) automated
2) automated with manual augmentation
3) manual
Cooperative Climate Data
people keeping track of weather for the government
the world meteorological organization
Responsible for the international exchange of weather data and certifies that the observation process does not vary between nations
Who is the sole source of weather watches/advisories/ warnings
National Weather Service
Weather watch
atmospheric a conditions are favorable for the type of weather specified
Weather watches generally have a
Larger geographic area and a longer life span
Weather advisory
the type of weather specified is immanent or is occurring and is a public inconvenience
Weather advisories generally have a
mid sized geographic area and are in effect for 6-24 hours
Weather warnings
the type of weather specified is imminent or is occurring and an immediate threat to life and/or property
Weather warnings generally have a
smaller geographic area with a time span of 1/2 to 1 hour
analogue method forecasting
comparing storm characteristics to one in past
climatological forecasting
a general prediction based on what most days are like during the current climate
short term forecasting (today, tonight) are _____% accurate
85-90%
Medium term forecasting (2-3) days out are ____% accurate.
80-85%
Longer range forecast (4-8 days out) are _______% accurate
close to 80%
there are _____ thunderstorms in progress at any given moment worldwide
2,000
thunderstorms are more common in
warmer, equatorial climates
what produces a line of storms?
cold fronts
Cumulous thunderstorms stage
1) updraft dominate
2) no rain/lightening
3) clouds getting darker and darker
Mature thunderstorm Stage
1) lightning/thunder/heavy rain
2) down drafts begin to dominate at some point
Dissipation thunderstorm stage
storm begins to die
sever thunderstorms produce hail that is ______ in diameter.
1” or larger
Straight lined sever thunderstorm winds produce winds of
50 knots 58 mph
how to crate a sever thunderstorm
increase winds aloft, get more tilt, separate updraft/downdrafts
Squaline
line of thunderstorms that take on a linear appearance
A bolt of lightning is about the diameter of a
Pencil
lighting can strike up to ____ miles away from the parent thunderstorm
10-20
thunderstorms are officially observed when thunder is first heard and end _____ minutes after last thunder is heard
15
tornadoes
a violently rotating column of air extending from the base of a cumulonimbus cloud and reaching the earths surface
summer heat is the number one_____
killer in the US
Ingredients for a tornados
1) mT air mass (warm moist air)
2) extremely unstable air mass
3) strong lifting mechanism
EF Scale
enhanced Fujita Scale: Measures Tornados damages
EF0 damage
Light damage (65-85mph)
EF1 damage
moderate damage (86-110 mph)
EF2 damage
considerable damage (111-135 mph)
EF3 damage
sever damage (136-165mph)
EF4 damage
Devastating damage (166-200mph)
EF5 damage
Incredible damage (201-318mph)
Ingredients for a tropical cyclone
1) form over the tropical oceans of the world
2) surface temperature of 81 degrees or higher
3) weak upper level winds with a anticyclone in upper levels above
Less than _____ % of Meso cyclones will make a tornadoe
20%
TRUE/FALSE: Spinning of air does NOT mean tornado
TRUE
cloud to ground lightning makes up ____ % of lightning strikes
20%
Heat Lightning
Lightning you can see in the distance
Hail occurs because _________
updraft/downdraft of a storm
large hail will often fall _____ of a tornado
Northeast
Baseball sized hail falls at a terminal velocity of _______
85 mph
Veering Wind
Winds which shift in a clockwise direction with time at a given location
Backing Winds
Winds which shift in a counter-clockwise direction with time at a given location
