Term
|
Definition
| An extremely large body of air whose properties of temperature and humidity are fairly similar in any horizontal direction at any given altitude. |
|
|
Term
| How is an airmass formed? |
|
Definition
| They form when air tesides over a flat region with homogeneous characteristics for an extended period of time. |
|
|
Term
| What are the classifications for airmasses? |
|
Definition
Continental Polar (cP)
Continental Tropical (cT)
Maritime Polar (mP)
Maritime Tropical (mT)
Continental Arctice (cA) |
|
|
Term
| What are the characteristics of Continental Polar? |
|
Definition
|
|
Term
| What are the characteristics of Continental Tropical? |
|
Definition
|
|
Term
| What are the characteristics of Maritime Polar? |
|
Definition
|
|
Term
| What are the characteristics of Maitime Tropical? |
|
Definition
|
|
Term
| What are the characteristics of Continental Arctic? |
|
Definition
|
|
Term
|
Definition
| The mass of air in the air column that increases with time. |
|
|
Term
|
Definition
| The mass of air in the air column that decreases with time. |
|
|
Term
| What are the resulting pressures and vertical motions of surface convergence? |
|
Definition
| Convergence at the surface and divergence aloft leads to upward vertical motion and low pressure. |
|
|
Term
| What are the resulting pressures and vertical motions of surface divergence? |
|
Definition
| Divergence at the surface and convergence aloft lead to downward vertical motion and hig pressure. |
|
|
Term
| In an upper air wave pattern, where would there be areas of convergence and divergence? |
|
Definition
| Convergence occurs when going into the pressure trough and divergence occurs when leaving the pressure trough. |
|
|
Term
|
Definition
| Regions where locally strong pressure gradients produce exceptoinally strong winds. |
|
|
Term
| Where are areas of convergence and divergence in straight jet streaks? |
|
Definition
Convergence Divergence
Divergence Convergence |
|
|
Term
| Where are areas of convergence and divergence in curved jet streaks? |
|
Definition
|
|
Term
| What are the impacts of certain alignments of multiple jet streaks? |
|
Definition
| When maximum divergence is aligned, a strong surface low develops. |
|
|
Term
| What is the role of friction into the life or death of a high or low pressure sytem? |
|
Definition
| The role of friction is to slow the wind whch causes the wind to flow into lows and out of highs. The lows fill and the highs evacuate. If there was friction aloft, systems would quickly die. |
|
|
Term
| What happens in stage 1 of the cyclone model? |
|
Definition
| This is the developmental stage. Two airmasses are bounded by a stationary front. Low pressure develops and fronts are formed. Cyclone counter clockwise flow begins. |
|
|
Term
| What happens in stage 2 of the cyclone model? |
|
Definition
| This is the mature clone stage. Fronts continue to move cyclonically around the low pressure. The cold front eventually catches the warm front. |
|
|
Term
| What happens in stage 3 of the cyclone model? |
|
Definition
| This is the dying cyclone stage. Occlusion takes place. The cyclone separates and is no longer associated with fronts. |
|
|
Term
|
Definition
| The collision of the cold front into the warm front. |
|
|
Term
|
Definition
| The transition zone between 2 airmasses of different densities. |
|
|
Term
| What are the four types of fronts? |
|
Definition
| Cold, warm, stationary, and occluded. |
|
|
Term
| What are the characteristics of a cold front? |
|
Definition
| Fast moving, sharp temperature drop, dramatic wind shift, narrow but strong precipitation, and isobar kinks. |
|
|
Term
| What are the characteristics of a warm front? |
|
Definition
| Slower moving, temperature increase, wind shift, wide spread precipitation, more gradual isobar kinks. |
|
|
Term
| What is a stationary front? |
|
Definition
| It's the boundary between warm and cold airmasses. Can be the results of a warm or cold front stalling out and becoming stationary. Can remain in one location for several days. |
|
|
Term
| What thermal processes are occuring during an occlusion? |
|
Definition
| As a cyclone evolves, the cold front will move faster than the warm front and eventually the two will collide and form an occluded front. |
|
|
Term
|
Definition
| It is NOT a front!! It's definced by a change in moisture characteristics. They're usually very narrow and may or may not have a wind shift. They are important to the study of thunderstorms. |
|
|
Term
| Explain the basic thermal circulation model. |
|
Definition
| Differntial heating creates a thermal low. Through PGF and convergence and divergence, a localized thermal circulation occurs. Examples are seabreezes, lake effect snow, and urban circulations. |
|
|
Term
| What are sea and land breezes results of? |
|
Definition
|
|
Term
| Explain how a sea breeze occurs. |
|
Definition
| During the day, the land heats more resulting in a sea breeze. |
|
|
Term
| Explain how a land breeze occurs. |
|
Definition
| At night, the land cools faster than the water resulting in a land breeze. |
|
|
Term
| What are the impacts of freezing parcipitation? |
|
Definition
| It can close cities, there are aircraft complications, and ice can bring down power lines and trees. |
|
|
Term
| What is supercooled water? |
|
Definition
| Ice nuclei are needed to promote freezing at temperatures below -15 degrees Celsius. If there are no ice nuclei, then supercooled water droplets form. |
|
|
Term
| How is supercooled water potentially damaging? |
|
Definition
| Supercolled water droplets will freeze on contact with a surface that is colder than 0 degrees Celsius. |
|
|
Term
| What types of vertical temperature profiles are needed for various forms of liquid and frozen precipitaion? |
|
Definition
SNOW: It comes really close to the line but does not touche it.
SLEET: Barely crosses the line.
FREEZING RAIN: Crosses the line big time but comes back across the line to the left.
RAIN: It's a diagonal from left to right. |
|
|
Term
|
Definition
| Precipitatin that starts as snow and falls through a deep warm layer melting it to rain. |
|
|
Term
| What is freezing drizzle? |
|
Definition
| It is similar to freezing rain but has smaller drops (.2-.5 mm) about the size of mist. |
|
|
Term
| Where do freezing rain and freezing drizzle typically occur in North America? |
|
Definition
| Just NW of the Great Lakes and a band from the N down and around and back up to the N. |
|
|
Term
| What is a lake effect snowstorm? |
|
Definition
| It is a winter strom that produces heavy snow falls on the down wind shores of inland bodies water. |
|
|
Term
| Where are lake effect snowstorm typically found in North America? |
|
Definition
| Mainly in the Great Lakes region but also from the Great Salt Lake in Salt Lake City, Utah. |
|
|
Term
| What is a typical synoptic setup for LES? |
|
Definition
| Low pressure to the East and high pressure to the West results in a funneling of cold air down across the Great Lakes causing heavy snowfalls on the downward side of the lakes. |
|
|
Term
| What conditions are needed to get LES? |
|
Definition
| Air temperatures must be sufficient for snow with temperatures between -5 degress Celsius and -25 degrees Celsius. The lake temps must be "warm" compared to air over the lake, a temp diff. from 10 degrees and 13 degrees Celsius between air and water. The lake cannot be frozen. |
|
|
Term
| What is the typical formation pattern of LES? |
|
Definition
| Divergence->moistening, warming, destabilization->convergence. |
|
|
Term
| What aspects can impact the strength of LES? |
|
Definition
| The longer time the air spends over the lake, the heavier the snowfall amounts. This is due to more evaporation of the water into the air. |
|
|
Term
| Under what conditions would you get wind parallel bands? |
|
Definition
| A result of strong winds coming across the short axis of a lake. |
|
|
Term
| Under what conditions would you get shore parallel bands? |
|
Definition
| Weak winds, heat from the lake causes air to rise and draw in air from both shores. |
|
|
Term
|
Definition
| An influx of unusually cold air into middle or low latitudes. |
|
|
Term
| What are the human impacts of cold waves? |
|
Definition
| Approximately 30-35 deaths a year, the elderly and males are more prone to cold related deaths. Nearly 75% of cold related deaths in the US are males. |
|
|
Term
| What are the economic impacts of cold waves? |
|
Definition
| They're greatest in the south. The Florida Citurs Crop is esp. prone to cold wave damages. In 83' $3.6 billion dollar loss and in 85" $2.9 billion dollar loss. |
|
|
Term
| How is the intensity of a cold wave determined? |
|
Definition
| Analysis of the departure from the normal temp. is used to determine the severity of the cold wave. |
|
|
Term
| What is the record low temperature in Oklahoma? |
|
Definition
|
|
Term
| What is the record low temperature in the US? |
|
Definition
|
|
Term
| What is the record low temperature in the Coontinental US? |
|
Definition
|
|
Term
| What aspects enhance the development of a polar or arctic air mass? |
|
Definition
| A high pressure is formed from the cooling of air in the lower troposphere. Light winds, long polar hights, and cloud free skies all enhance the lowering of the surface temperature. |
|
|
Term
| What are the characteristics of a polar or arctic air mass? |
|
Definition
| Temps reach -50F to -70F, but are relatively shallow (only 1-2 km deep). The air mass must move the air quickly in order to not modify to a warmer state. Upper-Level ridge on the W. Coast allows cold air to funnel down east side of Rocky Mountain. |
|
|
Term
| What is the cold wave synoptic pattern? |
|
Definition
| Strong low pressure system funnels cold air southward from Canada. As cold air moves southward, and upper level ridge begins toset in as the low pressure system occludes. The upper level ridge sets in place to trap the cold air in its place. |
|
|
Term
|
Definition
| The wind chill factors both temperatures and wind speed into the rate at which exposed flesh will cool. |
|
|
Term
| What is the 30-30-30 rule? |
|
Definition
| 30 mph wind and -30F temp will freeze flesh after 30 seconds. |
|
|
Term
| How do you convert Celsius to Farenhiet? |
|
Definition
| Take C temp and * by 1.8. + 32 degrees. |
|
|
Term
| How do you convert knots to mph? |
|
Definition
|
|
Term
| What is the NWS definition of a blizzard? |
|
Definition
Winds > 30 knots.
Falling or blowing snow w/visibility < 1/4 mi for at least 3 hours. |
|
|
Term
| What are the hazards associated with blizzards? |
|
Definition
| White out conditions, heavy snow falls or drifts, hypothermia. |
|
|
Term
| Where do blizzards typically occur in North America?? |
|
Definition
| The Northern part of the US. Just West of Wisconsin. |
|
|
Term
| What are the Rocky Mountain Cyclone Blizzard steps? |
|
Definition
A low pressure system develops near front range of the Rocky Mountain.
The low strengthens, drawing cold air down from Canada.
A blizzard develops on the back side of the low pressure system.
Typically more sever. |
|
|
Term
| What are the Alberta Cyclone Blizzard steps? |
|
Definition
It involves much colder air from Canada.
There is usually less falling snow and more blowing snow involved.
Similar to the Rocy Mtn. Cyclone Blizzard, there are blizzard conditions on the back side of the low pressure system. |
|
|
Term
| What are some blizzard survival safety tips? |
|
Definition
Have a winter storm survival kit.
Carry sand and shovel in your car.
Stay with your vehicle.
Carry a cell phone. |
|
|
Term
| What is the global circulation? |
|
Definition
| Global circulation is an average, large-scale flow of air around the world. Winds at a given time and place will vary locally. |
|
|
Term
| What is the single cell global circulation model and why is it inaccurate? |
|
Definition
| Warm air rises above the equator and cold air sinks over the poles. Flow generated from the rising and sinking air creates the circulation. Since the Earth is rotating, this circulation breaks up. Air flow aloft does not make it from the equator to the poles and air at the surface does not flow from polt to equator. |
|
|
Term
| What are the three cells in the revised global circulation model? |
|
Definition
| Hadley cell, ferrel cell, polar cell. Flow converges near the equator in the Intertropical Convergence Zone. |
|
|
Term
| What are the general pressure, precipitation, and wind flow patterns as a result of the three cell model? |
|
Definition
| The ITCZ and mid-latitudes are the wet regions while the polar regions and subtropical highs are dry. |
|
|
Term
| Why is global circulation important? |
|
Definition
| Global circulation acts to redistribute the uneven heating of the Earth. There is always weather due to the un-even heating of the surface of the Earth. |
|
|
Term
| What is the Rossby flow pattern? |
|
Definition
| The "wavy" pattern in the atmosphere shows 3-6 centers of highs and lows are present around the globe with a spacing of approx. 4000-6000 km. |
|
|
Term
| How do you determine the number of global waves in the Rossby flow pattern? |
|
Definition
| By counting the # of lows. |
|
|
Term
| What are the general surface and upper air weather patterns in January and July? |
|
Definition
JAN: High pressure system
JULY: More of a low pressure system. |
|
|
Term
| What global ocean currents impace North America? What are their names? and do they bring cold or warm water? |
|
Definition
Canary Current: Cold.
North Pacific Drift: Warm.
Alaskan Current: Cold.
N. Equatoril Current: Warm.
Equatorial Countercurrent: Warm.
Labrador Current: Cold.
W. Greenlad Drift: Cold. |
|
|
Term
|
Definition
| El Nino Southern Oscillation. |
|
|
Term
| What is the definition of ENSO? |
|
Definition
| The warming of the Sea Surface Temps (SST) along the equator from S. America out 5000 mi. |
|
|
Term
| What values constitute a weak or strong ENSO? |
|
Definition
| Weak events +1C; Strong events +4C. |
|
|
Term
|
Definition
| By buoys installed in the late 1980's to probide surface wind, air temp, and sea temp and currents of upper several hundred feet of the ocean. |
|
|
Term
| What is the Walker Circulation? |
|
Definition
| Process where normally surface wind blows from E-W along the equator as a result of low pressure in the westerm Pacific (near Australia) and high pressure in the eastern Pacific Ocean (near S. America). |
|
|
Term
|
Definition
A change in the sea surface temp results in a change in the pressure pattern across the equatorial Pacific. Thus the Walker circulation changes.
The trade winds weaken or revers, thus, normal easterly winds weaken or become westerly.
with weaker trade winds, warm water that "piled up" in the western Pacific sloshes eastward.
Low and hih pressure areas move creating differnt temp, and precip patterns. |
|
|
Term
|
Definition
It typically follows an el nino as the atmosphere tries to correct, but it "over does it" a bit.
The walker circulation strengthens once again.
Unusually cold water in the E. Pacific Ocean.
Opposite to El Nino in terms of SST and Pressure Patterns across equatorial Pacific, but not quite opposite in changes in gobal patterns.
Cold air outbreaks occur in NW and N US, but it can lead to drought conditions across the S and W US. |
|
|
Term
| What are the consequences of El Nino? |
|
Definition
| Coastal storms, typically warmer than normal, drought conditions in the Pacific NW, wet along Gulf Coast, more hurricanes. |
|
|
Term
|
Definition
Southern Oscillation Index-- Pressure at Tahiti-Pressure at Darwin.
Where pressure is expressed as departure from normal. |
|
|
Term
| What is the Mutivariate ENSO index? |
|
Definition
| Factors sea-level pressure, the e-w, and n-s components of the surface winds, SST, surface air temp, and total amount of cloudiness into the index. |
|
|
Term
| What are the variables used to calculate the ENSO? |
|
Definition
El Nino- + numbers (red)
La Nina- - numbers (blue) |
|
|
