Extreme Weather Exam 1

Front 1

why do we have weather?

Back 1

we have weather because of the heat from the sun and the movement of the air. The earth has large global patterns in the atmosphere caused by the interactions between solar radiation, the oceans, diverse landscapes, and motion in space. It is entirely dependent on the sun. The sun warms the atmosphere and is fundamental to atmospheric composition, and the distribution of this heat across the planet (such as the heating being most intense near the equator and the least intense at the poles) produces global wind patterns and contributes to the formation of clouds, storms and rainfall.

Front 2

What is the weather severity continuum?

Back 2

A scale describing the impact of weather.

Benign weather - gentle, mild

Nuisance weather - inconvenient, no significant problems or danger

Severe weather - any weather event with potential to cause damage or loss of human life

Extreme weather - unexpected, unusual, unpredictable weather. Weather at the extremes of historical distribution.

Front 3

Outline the extreme weather events of the spring and summer.

Back 3

Hurricane season - June 1 to November 30, peaks September 10

Generally 14-21ish named storms in a season, of which 6-11 could become hurricanes, of which 2-5 could be major ones.

Front 4

what are climate normals?

Back 4

climate normals are 30-year averages for climate variables like temperature and precipitation. They provide a baseline that allows us to compare a location’s current weather to the average weather that location would expect to see — whether a particular day is cooler or warmer than normal, if a particular month is wetter than normal, or if the growing season is longer than normal.

Front 5

what else are climate normals useful for?

Back 5

drought assessment, freeze risk for crops, snowfall prediction, travel

Front 6

how are climate normals calculated?

Back 6

NCEI (National Centers for Environmental Information) updates the official Climate Normals every ten years. The statistical calculations are taken from over 15,000 federal weather stations that observe temperature precipitation and snowfall. each update to the climate normals represent the last 30 years.

Front 7

what are creeping normals? Give examples.

Back 7

Creeping normalcy refers to the way major and often unacceptable change can be accepted as normal if it happens slowly and unnoticed increments. It is often used to explain indifference to environmental change. For example, people may tolerate excessive smog in a particular city that worsens over decades. People may get used to everyone being sick all the time from the large amounts of virus transmissions and see these as normal.

Front 8

what are wildfires and how are they caused?

Back 8

A wildfire is a fire that burns out of control in a natural area, like a forest, grassland, or prairie. They can sometimes start from natural causes, like lightning, but are most often caused by humans, such as campers who did not put out their campfire correctly. Nearly 85% of wildfires in the US are human caused. Campfires, burning of debris, equipment use and malfunctions, negligently discarded cigarettes, and arson. Wildfires recently have been majorly exasperated by the extreme heat, as well as strong winds and prolonged drought. This is true of the forest fires in Western Canada and the USA. The Canada wildfires usually start around August, this year they started in April.

Front 9

What was the cause of the smoke plumes over Buffalo this summer?

Back 9

The Canada wildfires created the smoke plumes which were brought downward by winds.

Front 10

What are high and low pressure systems?

Back 10

Air is actually super heavy. The pressure caused by all the nitrogen and oxygen and other gasses in the air stacked on top of each other equates to about 15 pounds pressing on our bodies, which we don’t notice because we are used to this. Not all areas have the same air pressure. Some have more pressure than their surroundings, and some areas have less. Areas that have less pressure are called low pressure systems. Low pressure systems suck air into them because nature wants everything to have equal pressure. By doing this they generally create winds and undesirable weather. High pressure systems have more air pressure than their surroundings. They are constantly pushing air away from them into the areas that have lower pressure. They are often associated with clear blue skies.

Front 11

What was the role of high and low pressure systems in the wildfires and smoke plumes this summer?

Back 11

The part of Canada where wildfires occur is in a high pressure system, so it is pushing air away from itself to redistribute pressure, resulting in smoke plumes flowing into the USA, where there is a lower pressure system.

Front 12

What were the effects of wildfire smoke on life in Buffalo during the summer?

Back 12

Bad quality of air, high AQI, hazy orange skies, people spending time indoors etc.

Front 13

What is the AQI?

Back 13

AQI is the Air Quality Index. It is a code that can be used to determine the amount of particle pollution in the air. Green is an index of 0-50, when air quality is acceptable and air pollution poses little risk. Yellow is 51-100 when air quality may cause issues for some people. Orange is 101-150, which is officially unhealthy for sensitive groups. Red is 151-200, which is unhealthy for all people. Purple is 201-300, meaning very unhealthy, and maroon is 301+, when conditions are hazardous for everyone.

Front 14

How did wildfires affect the view of the sun in western New York?

Back 14

On some days this summer, the air pollution settled over the skies of Buffalo New York in a way that made the sun look hazy, orange, and not very bright, sometimes even altogether “disappearing” behind the haze.

Front 15

What are fire whirls? What are fire tornados?

Back 15

Fire whirls are whirlwinds induced by fire and often composed of flame and ash. They start with a whirl of wind, often made visible by smoke, and may occur when intense rising heat and turbulent wind conditions combine to form whirling eddies of air. If the heat intensifies enough and there are stronger updrafts as well as enough dry fuel, a fire whirl can grow into a fire tornado, which is a rotating funnel that fully extends from cloud to ground, moving at incredible speeds. A real tornado made of fire and ash. Fire tornados are rare but are becoming more common due to climate change. They are almost impossible to extinguish and often have to be left to sort itself out.

Front 16

List eight causes of the Lahaina wildfire.

Back 16

1. winds flowing from high to low pressure. The Northeast trade wind blows the moist wind towards up the eastern, damper side of Maui, where it tumbles over towards the western leeward side and meets the dryer conditions of the western side which is dryer and warmer and has lower air pressure.

2) The dry air and low humidity of the western side allows perfect conditions for wildfires.

3) There was a drought already in place making everything more conducive to fires.

4) Invasive grasses take up much of the western side, and they are very dry and flammable. They are buffel grass, molasses grass, and Guinea grass.

5) There was a spark from a downed power line.

6) Hazard sirens were not played because a city official feared people would assume it meant flooding in the east side, and run straight into the fires on the dryer western side.

7) Maui has a wet, windward eastern side with high pressure, which sends air westward into the western, warm and dry leeward side, which has lower pressure.

8) Lahaina’s fire hydrants had low water pressure, impeding ability to put out the fires.

Front 17

What is a heat dome?

Back 17

Heat domes are caused when atmosphere traps hot ocean air, is if sealed in a jar. This high pressure blockage works in conjunction with a disruption in the jet stream, which undulates and creates an Omega Block, which traps the pocket of warm air in a dome.

Front 18

Expand on the causes of heat domes.

Back 18

They are caused by being in a high pressure part of the atmosphere. The air is heavy pushing air down towards the ground. Jet streams, the flowing currents of air in the atmosphere, become disrupted in these heat dome areas and start flowing in the shape of an Omega Block, creating large circles where the warm air being pushed down to the ground is then compressed by the pressure, which releases even more heat that begins to rise, and then get pushed back down by the heat seal, creating a self reinforced heat dome loop.

Basically,

when high pressure is large enough, the west to east airflow has difficulty going around the high. This interrupts the normal eastward progression of our weather. The high pressure becomes sandwiched between two low pressure systems.

Front 19

How are heat domes sustained?

Back 19

The omega block shape of the jet stream pattern paired with the hot air getting trapped from the atmosphere creates a loop effect which keeps hot air trapped in the same place and causes heat waves. In the absence of clouds, the shining a sun will further heat the air.

Front 20

What is a jet stream?

Back 20

A jet stream is a fast flowing, narrow, meandering air current in the atmosphere of the Earth. The main jet streams on Earth are located near the altitude of the tropopause and are westerly winds.

Front 21

How do jet streams contribute to extreme weather?

Back 21

Jet streams can become corrupted by warmer weather in a high pressure ridge, stalling and becoming even slower and creating wider meandering paths. This causes the weather pattern to be “stuck” and heat waves linger and longer storms happen.

Front 22

How does climate change influence Jet streams?

Back 22

The Arctic ocean is warming faster than the lower latitudes, narrowing the difference in temperature. This reduces the pressure gradient which slows the jet stream. Slower jet streams has a stronger meridianal flow and a tendency to stall, creating intense conditions.

Basically, climate change is weakening the jet stream (slower and wobbly) which leads to more extreme weather events.

When the jet stream bends into five waves across earth, this is known as the “wavenumber 5 pattern”, and leads to heatwaves across the northern hemisphere.

Front 23

What are the top 3 most severe weather types in Western NY in both winter and summer?

Back 23

Winter: 1. lake effect snow 2. heavy snow 2. high wind (tied with heavy snow) 3. freezing rain

Summer: 1. thunderstorm 2. high wind 3. heavy rain

Front 24

What are the role of polar vortexes in jet stream patterns?

Back 24

A weak polar vortex can create a weak jet stream pattern. The colder arctic air is harder to contain, which can now escape from the polar regions into the USA. Winters may experience cold outbreaks.

Front 25

What are the great lakes’ contributions to our weather? How do they impact it?

Back 25

1. the lakes moderate temperature, causing cooler springs and warmer summers.

2. there is lake effect snow and snow bands, especially in the south towns.

3. Lake Erie is said to be where thunderstorms go to die. (This is in the spring/early summer when the lake is cool)

4. The season of lake disaster (November)

5. Clear skies near shorelines in the spring

6. a cooling effect - a cooling breeze blows across lake

7. buffalo is a windy city because of the lakes

8. cooling springs and warmer falls (esp in fruit belt)

Front 26

When is the lake effect rain season?

Back 26

Late summer and early autumn + winter of each year.

Front 27

When is the lake effect snow season?

Back 27

Late autumn and winter. When the waters are warmer than the air passing over the lake this is when lake effect snow occurs. When the lake freezes over, lake effect snow happens no more. Lake Erie is not freezing over in recent years, extending the lake effect snow season.

Front 28

Why is November the season of lake disaster?

Back 28

In the transition between fall and winter, there is a strong gradient between warm, moist air to the south, and cold, dry air to the north. This produces low pressure systems that move across the country.

The lake water retains heat relative to the air.

These deep low pressure systems tracking over the Great Lakes are intensified by the lake’s relatively warm water which makes it easier for the air to lift — injecting heat and moisture and intensifying the storms.

Front 29

What is a storm surge?

Back 29

A tsunami-like phenomenon of rising water commonly associated with low pressure water systems, like cyclones. It is measured as the rise in water levels above the normal tidal level, not including waves.

Front 30

What is a seiche?

Back 30

A seiche is a temporary disturbance or oscillation in the water level of a lake or partially enclosed body of water. Seiche translates to “to sway back and forth”.

A seiche is the same as a storm surge except that the surface water in a seiche oscillates by sloshing between opposing shores within the lake basin, decreasing in height with each rocking back and forth until it reaches equilibrium.

Front 31

What are seiches caused by?

Back 31

Rapid pressure changes and strong winds blowing across a lake can push water from one end to the other — the water pileup at one end of the lake is matched by a drop in water level at the opposite end. When winds weaken or reverse, the pileup of water rushes back to its original side of the lake raising water levels there. It can continue to slosh back and forth until equilibrium is achieved.

Front 32

Talk about the seiches of Lake Erie.

Back 32

Lake Erie is known for producing the most and largest seiches of the great lakes, because it is the shallowest of the lakes and its orientation to prevailing Southwest winds.

Seiches in lake erie have been measured to move up to 8 feet in height, and it can take a full day or two for the lake to complete equilibrium.

Front 33

What are ice tsunamis (aka ice shoves)?

Back 33

An ice shove is a surge of ice from an ocean or large lake onto the shore.

Front 34

What causes the ice shoves of the Great Lakes?

Back 34

Ice shoves happen on Lake Erie after freezing temperatures, strong winds, and water combines which forms literal waves of chunky ice.

Front 35

What is a meteotsunami?

Back 35

Meteotsunamis are neither a surge nor seiche. They are tsunamis of atmospheric origin. They are triggered by weather systems instead of earthquakes like true tsunamis.

Front 36

How are meteotsunamis caused?

Back 36

As a thunderstorm moves across a lake, atmospheric pressure and gravity push up and down on the water surface in an oscillating way. That causes a wave on the leading edge of a storm. This wave moves towards the shore and can be amplified by shallow waters, inlets, bays, and other coastal features. If it moves at the same speed as the storm above it, the storm can continue to charge and amplify the wave. The wave created by the changing pressure and thunderstorm causes a sudden change in water level that can catch people off guard.

Front 37

What are atmospheric rivers?

Back 37

Atmospheric rivers are bodies of flowing water vapor in the atmosphere that carries saturated air from the tropics to higher latitudes.

Front 38

What do atmospheric rivers cause and where do they happen in the USA? Are the effects positive or negative or both?

Back 38

Lots of rain and snow for the western USA, especially California, because of the Pineapple Express leading saturated air from the tropics to the states.

The effects of atmospheric rivers can be and are beneficial, as weather from atmospheric rivers do make up to 50% of California’s water supply. However the weather caused by ARs can be devastating as well. They can create hazards and emergencies by flooding when there is too much rain falling too fast. Mudslides can also then occur which topple people and properties.

Front 39

How to atmospheric rivers form?

Back 39

Things start in tropical regions. The warm temperatures of the tropics cause ocean water to evaporate and naturally rise higher into the atmosphere. Wind aids the water vapor in spreading higher and further into the atmosphere and into higher latitudes. Once the water vapor meets land and begins moving up and over mountains, it meets cooler air and forms into water droplets which then fall as any form of precipitation.

Front 40

How much water does the average atmospheric river hold?

Back 40

The average atmospheric river contains water vapor equivalent to the the flow of water at the mouth of the Mississippi River.

Front 41

What were the impacts of atmospheric rivers on the west coast and California in 2023?

Back 41

nine back to back atmospheric rivers brought serious hazards to the west coast, specifically California, in 2023. This was the longest stretch of continuous atmospheric river conditions in the 70 years of recording. There was extreme rainfall and flooding (31 atmospheric river storms from October to March), rain-on-snow events, widespread power outages, landslides, and debris flows.

Although the onset of the atmospheric did quench California’s drought, it brought too much wetness too fast.

Then there was the Big Melt in early April, when snow water equivalent to 61 inches melted.

Front 42

How fast are winds during a tropical storm vs an all-out hurricane?

Back 42

Tropical storms start at sustained winds of 39 mph to 73 mph. According to the Saffir-Simpson hurricane scale, a Category 1 hurricane starts at 74mph sustained winds. Category 2 at 96mph, 3 at 111mph, 4 at 130mph, and 5 at 157mph or above.

Front 43

What 3 specific conditions are needed in the tropics to form tropical storms and hurricanes?

Back 43

1. warm waters (80°F or above)

2. a lifting mechanism (winds)

3. wind shear

Front 44

What are the significance of wave pouches?

Back 44

A wave pouch is the recirculating cat’s eye in the critical layer that represents a sweet spot for tropical cyclogenesis where a proto-vortex may form and grow.

Front 45

What is the significance of wind shear?

Back 45

Wind shear is a change in wind speed with height. Strong upper-level winds destroy the storms structure by displacing the warm temperatures above the eye and limiting rising air parcels. Hurricanes will not form when the upper-level winds are too strong.

Front 46

What is rapid intensification? Are they becoming more common?

Back 46

When a hurricane strengthens rapidly over a short period of time. More specifically, it is accelerated growth of at least 35 mph in 24 hours or less.

Rapid intensification is happening more often in recent years. Climate change makes the occurrence of strong hurricanes that rapidly intensify more likely. Whether or not this will increase the overall amount of hurricanes is yet to be determined.

Front 47

Describe the events of Hurricane Lee.

Back 47

At the start of September, Hurricane Lee was forecasted to rapidly intensify into a major Category 4 storm. It at one point peaked at a Category 5. Hurricane Lee eventually stalled out.

Front 48

What are the characteristics of the hurricane eye?

Back 48

The eye is characterized by light winds and clearer skies, surrounded by a towering, symmetric eye wall.

Front 49

How is the hurricane eye formed?

Back 49

Air descends from the surface to the tropopause and most air exhausts outwards away from the center. However, some air exhausts inwards, converges and then descends (high to low pressure). The descending air compresses and warms, reducing relative humidity and this prevents clouds from forming — clearing skies.

Descending air adjacent to the inner eye wall (which is dry) mixed with air in the eye wall (moist) leading to evaporative cooling, increasing the descending air’s density and reinforces the sinking.

Also consider the weak pressure gradient force (high to low) and gravity, which draws the air down.

Front 50

What are cold wakes?

Back 50

Cold wakes are trails of cooler water along hurricane tracks that are a result of wind-induced mixing and turbulence that brings cold waters at depths to the surface.

The cooler water can weaken another hurricane following behind, and the duration of the chillier water lasts less than a week.

Front 51

What is El Niño?

Back 51

El Niño is a climate pattern of unusual warm waters occurring in the East Pacific Ocean that sends rain to South America and drought to Hawaii.

Front 52

What is El Niño’s effect on the hurricane season?

Back 52

El Niño has been linked to reductions in Atlantic hurricane activity due to the enhanced Tropical Jet Stream and increased vertical wind shear.

The enhanced Tropical Jet Stream can help steer the tropical systems to the north and eventually the northeast, “curving” them before they make landfall…

Front 53

How is a hurricane structured?

Back 53

The main parts of a tropical cyclone are the rain bands, the eye, and the eye wall. Air spirals in toward the center in a counterclockwise pattern in the northern hemisphere (clockwise in the southern) and out the top in the opposite direction.

Front 54

What are the stages of a hurricane?

Back 54

1. Disturbance formation

2. Tropical disturbance

3. Tropical depression

4. tropical storm

5. hurricane

6. dissipation

Front 55

What is the “dirty side” of a hurricane?

Back 55

The dirty side of the hurricane is considered the right side, or the upper right quadrant in the direction the storm is traveling. The dirty side is the more dangerous side in terms of storm surge, winds and tornadoes.

Front 56

What is the Fujiwhara Effect?

Back 56

The Fujiwhara Effect describes the phenomenon of 2 hurricane passing close by each other — they perform an “intense dance” around the common center.

Front 57

What is a hurricane in the eastern hemisphere called?

Back 57

A typhoon.

Front 58

How do Cape Verde storms compare to home grown tropical storms?

Back 58

Cape Verde hurricanes don’t often strike the US but when they do they strike hard. Cape Verdean storms start slowly and curve up the North Atlantic before reaching maturity in August-September. Hurricanes don’t often make landfall in Cape Verde, burn turn northward beforehand.

Front 59

What is the Bermuda high and how are they formed?

Back 59

A high pressure system located over the Atlantic Ocean that borrows its name from a nearby island chain and had the ability to influence the movement of tropical systems in the Atlantic basin. Ocean waters that are cooler than land cause the Bermuda High to form.

Front 60

What do Bermuda highs do?

Back 60

A normal Bermuda High often directs hurricanes to move along the East Coast and then eventually back out over open waters.

Front 61

What is the cone of uncertainty?

Back 61

The cone of certainty refers to a graphic that projects the probable track of the center of a tropical cyclone.

Front 62

What is a spaghetti plot?

Back 62

A spaghetti plot is the nickname for the computer models that show potential tropical cyclone paths using continuous flow lines.

Front 63

What is the meaning of teleconnection?

Back 63

A teleconnection is a connection or correlation between meteorological phenomena which occur a long distance apart.