METEO 3 Lesson 8 Images

Lesson 8: The Role of Stability in Thunderstorm Formation

 

The Ups and Downs of Air Parcels

large burners

Interior view of a hot air balloon with a bright flame and colorful canopy.
large burners
Text description of the large burners image.

The image depicts the interior view of a hot air balloon as it ascends. A bright, intense flame is centrally visible, shooting upward from a metal burner to heat the balloon. The burner is surrounded by a network of metallic and rubber tubes. Above, the balloon canopy is highlighted, showcasing vibrant colors arranged in a pattern of adjacent chevrons. These colors include shades of orange, yellow, red, and green, transitioning into a deep purple at the upper sections. There is a partially visible person in the lower part of the image, which is mostly focused on the balloon components and the flame itself. The sky in the background is clear, contributing to the visibility of the flame's brightness.

 

Testing the Stability of the Atmosphere

condensation is a warming process

Diagram showing water phase transitions with energy values between ice, liquid, and vapor.
condensation is a warming process
Text description of the condensation is a warming process image.

The image depicts the phase transitions of water in three states: ice, liquid, and vapor, along with the energy changes associated with each transition. The diagram is divided horizontally into three sections labeled "Ice," "Liquid," and "Vapor." Each section represents a different state of water with a colored gradient background showing increasing energy from left to right.

The phase transitions are illustrated with arrows: "sublimation" and "deposition" between Ice and Vapor, "melting" and "freezing" between Ice and Liquid, and "evaporation" and "condensation" between Liquid and Vapor. Energy values in calories per gram are indicated beside the arrows. The diagram shows "80 cal/g" for melting and freezing, "600 cal/g" for evaporation and condensation, and "680 cal/g" for sublimation and deposition. A vertical arrow on the right indicates the direction of increasing energy.

Credit: David Babb@ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

 

Stability, Clouds, and Precipitation

fair-weather cumulus

A building with antennas and trees under a blue sky with scattered white fair-weather cumulus clouds.
fair-weather cumulus
Text description of the fair-weather cumulus image.

The image depicts a bright blue sky dotted with scattered white fair-weather cumulus clouds. In the lower section, a building with several antennas and satellite dishes is visible, partially obscured by a line of green trees. The building is light-colored with some rooftop equipment visible. A tall, slender chimney or pole stands to the left of the building, partially framed by the tops of the trees.

Credit: David Babb@ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

cumulus congestus

Large cumulus cloud over a landscape with houses and trees.
cumulus congestus
Text description of the cumulus congestus image.

The image depicts a large, billowing cumulus cloud dominating the sky, with a bright white upper portion and a darker gray base. The cloud contrasts sharply against a deep blue sky, with scattered wisps of lighter clouds surrounding it. Below this towering cloud formation is a landscape featuring a row of houses with a few trees, silhouetted against the foreground. A gently sloping, tree-covered hill rises in the background, while two tall pine trees frame the right side of the image.

Credit: Steve Seman@ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

cumulonimbus clouds

Boats docked at a marina with blue sky and cumulus clouds.
cumulonimbus clouds
Text description of the cumulonimbus clouds image.

The image shows a tranquil marina scene under a clear blue sky. Several boats and sailboats are docked at a pier, with a couple sailing on the calm water. The foreground features a gravelly shore with scattered stones and two wooden posts standing on the edge. In the background, puffy cumulus clouds rise against the blue sky, creating a serene and picturesque atmosphere. A line of buildings and trees can be seen further in the distance along the right side of the image.

Credit: Steve Seman@ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

1745Z mosaic of composite radar reflectivity

Radar map showing precipitation over the southeastern United States with varying colors indicating intensity.
1745Z mosaic of composite radar reflectivity
Text description of the 1745Z mosaic of composite radar reflectivity image.

This image is a radar map displaying weather patterns over the southeastern United States. The map features the outlines of several states, including parts of Louisiana, Mississippi, Alabama, Georgia, South Carolina, and Florida. The background is black, with various colors representing different intensities of precipitation. The colors range from blue and green, indicating light precipitation, to yellow, orange, and red, representing heavier precipitation. The map includes a color scale on the left side, labeled "DBZ," with increments from 5 to 75, indicating the strength of the precipitation detected by the radar. The heaviest precipitation is concentrated in Mississippi and Alabama, with scattered patches throughout the region.

Credit: WSI Corporation

entire layer of air glides upward

Diagram showing a warm front with labeled “Surface warm front,” “Frontal Zone,” and slope measurements.
entire layer of air glides upward
Text description of the entire layer of air glides upward image.

The image is a cross-sectional diagram illustrating the dynamics of a warm front. At the bottom, there is a green horizontal strip labeled "Surface warm front," representing the Earth's surface. Above this strip, a large purple triangular region is labeled "Frontal Zone," highlighting the area where two air masses meet. A black arrow originates from the left side, labeled "Air glides up the frontal zone," indicating the movement of air upwards along the frontal boundary. A purple arrow also points towards the slope with the label "Frontal Zone." To the right, the slope is noted with a vertical distance of "1 km" and a horizontal distance of "300 km," with the slope ratio written as "Slope = 1/300." The background gradient transitions from blue at the bottom to pink at the top, suggesting changes in temperature or air mass composition.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

12Z surface analysis on December 16, 2010

Weather map of southeastern United States showing fronts, temperatures, and pressure systems.
12Z surface analysis on December 16, 2010
Text description of the 12Z surface analysis on December 16, 2010 image.

The image is a weather map of the southeastern United States, showing various weather patterns, symbols, and data points. The map features several states outlined with lines of latitude and longitude, with a focus on Tennessee, Georgia, Alabama, and surrounding areas. A blue line with triangular symbols represents a cold front moving across the map from the southwest to the northeast, passing through Arkansas and into Kentucky. A red dashed line indicates a warm front or low-pressure trough, curving from eastern Tennessee into South Carolina. Colored numbers and symbols are scattered across the map, representing temperature, wind direction, and atmospheric pressure at various weather stations. Areas of high (H) and low (L) pressure are marked with their respective symbols. The map's background is predominantly white, with colored lines and symbols providing a detailed overview of the current weather conditions.

Credit: Weather Prediction Center

mosaic of composite reflectivity at 12Z on December 16, 2010

Weather radar map showing precipitation across central and eastern U.S. with blue, green, and yellow colors indicating varying rainfall intensity.
mosaic of composite reflectivity at 12Z on December 16, 2010
Text description of the mosaic of composite reflectivity at 12Z on December 16, 2010 image.

The image is a weather radar map displaying a wide area of precipitation across several states in the central and eastern United States. The map has a black background with state boundaries outlined in thin yellow lines. The precipitation is depicted in various colors: blue indicates lighter precipitation, while green and yellow show moderate levels, and a hint of red suggests heavier rainfall. The system stretches from the western parts of the depicted region to the east, covering states including Missouri, Illinois, and Kentucky, reaching as far east as Virginia. The gradient of colors indicates intensities of rainfall, with the heaviest concentrated in the central area of the system.

Credit: WSI Corporation

 

Lightning

nearly 80 percent are male

A pie chart showing lightning fatalities: 79% Male and 21% Female.
nearly 80 percent are male
Text description of the nearly 80 percent are male image.

The image is an infographic showing lightning fatalities by gender in a pie chart format. The chart is situated on a dark blue background with two circular logos in the top corners. The left logo belongs to NOAA, featuring a seagull and waves, while the right logo is for the National Weather Service, showing a cloud and lightning bolt. The pie chart is divided into two sections: a larger light blue segment covering 79% labeled "Male," and a smaller pink segment representing 21% labeled "Female." Below the chart, the text states the data is based on 352 cases from 2006 through 2016.

Credit: National Weather Service

another slow-motion video of a lightning strike (0:13)

another slow-motion video of a lightning strike
Text description of the another slow-motion video of a lightning strike video (0:13)

The image depicts a bright lightning bolt against a dark sky. The lightning is jagged and runs vertically from the top to the bottom of the image, creating an intense contrast with the surrounding darkness. In the lower left corner, a silhouetted outline of trees is visible, adding depth to the composition. The image is in black and white, enhancing the starkness of the lightning against the background.

Credit: NOAA

same video slowed down even more (0:07)

same video slowed down even more
Text description of the same video slowed down even more video (0:07)

The image captures a vivid lightning bolt streaking across the sky. The lightning is bright and jagged, with sharp edges creating a pronounced zigzag pattern. The background is dark, possibly indicating nighttime, which contrasts sharply with the intense white glow of the lightning. In the foreground, there is a silhouette of treetops at the bottom of the image, adding depth to the composition.

Credit: NOAA

graupel

Small white hailstones on brown wood chips.
graupel
Text description of the graupel image.

The image depicts a close-up view of small white hailstones scattered across a layer of brown wood chips. The hailstones are spherical and vary slightly in size, creating a speckled pattern against the dark, textured background of the wood chips. The wood chips are of various sizes and shapes, adding a rough texture to the scene. There are a few thin sticks and pieces of debris interspersed among the hailstones, contributing to the natural setting.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

they become electrically charged (0:04)

they become electrically charged
Text description of the they become electrically charged video (0:04)

The image features a gray background with several white snowflake shapes evenly scattered throughout. Among the snowflakes are red cross symbols with a white outline and small circular icons that contain horizontal yellow bars, suggesting a pause or stop sign. In the top right corner, there is a small blue and white logo.

Credit: NOAA

animation about lightning casualties (0:22)

animation about lightning casualties
Text description of the animation about lightning casualties video (0:22)

The image is a graphic illustrating the "Threat of Lightning Casualties" and is designed as a chart with three main phases: "Thunderstorm Approaching," "Thunderstorm Overhead," and "Thunderstorm Departing." A blue background encompasses the chart, with a small NOAA logo in the upper left corner. A thick yellow line represents "Lightning Risk," starting high as the thunderstorm approaches, peaking as the thunderstorm is overhead, and declining as the storm departs. Another yellow line indicates "Exposure To Risk," which has a similar pattern but peaks slightly lower. The bottom section of the chart is shaded red, labeled "Lightning Casualties," indicating a higher risk area mainly when the storm is overhead.

Credit: NOAA

 

Thunderstorm Climatology

map from NASA showing worldwide lightning strikes

Color-coded global map indicating data values, with a scale from 0.1 to 70.
map from NASA showing worldwide lightning strikes
Text description of the map from NASA showing worldwide lightning strikes image.

The image is a global geographic map showcasing a color-coded data visualization. It displays various regions in hues that range from black, red, orange, yellow, green, cyan, blue, purple, to gray, representing a scale from 0.1 to 70, indicated on a vertical legend at the right. Purple and black dominate the equatorial region of Africa, with high values shown in black. The orange and red colors are prevalent in regions such as South America, Central Africa, and Southeast Asia, indicating mid-range values. The blue and greens are visible in North America, Europe, and parts of Asia, suggesting lower values. The map includes latitude and longitude markers across the top and sides, providing geographic reference points.

Credit: NASA

sea breeze is actually a three-dimensional circulation

Diagram of sea-breeze circulation showing warm land with rising clouds and cool sea with airflow patterns.
sea breeze is actually a three-dimensional circulation
Text description of the sea breeze is actually a three-dimensional circulation image.

The image illustrates the concept of sea-breeze circulation. On the left side, cumuliform clouds are depicted rising over a warm land surface, with red arrows showing updrafts labeled "Typical updraft Speed: 2 - 5 m/s." The warm land is colored brown and labeled "WARM." A blue body of water on the right is labeled "COOL." Arrows over the water indicate the airflow recirculating with speeds labeled "~5 - 10 m/s." The depth of the maritime air is indicated as "~1 km" with a vertical arrow. A horizontal arrow stretching from the land to the sea shows a distance of "on the order of 10 - 100 km," illustrating the extent of the breeze. Yellow text on the land reads, "Sea-breeze front advances inland at speeds between 0 and 10 m/s."

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

Lake Okeechobee

Map of Florida showing the location of Lake Okeechobee with a red pin.
Lake Okeechobee
Text description of the Lake Okeechobee image.

The image is a map illustrating the state of Florida in the United States. The map highlights main highways and cities, with a focus on showing the location of Lake Okeechobee. The map features a blue body of water representing the Gulf of Mexico on the left and the Atlantic Ocean on the right. Major cities such as Miami, Tampa, and Orlando are labeled, along with smaller cities, highways, and geographic landmarks. A red pin marks Lake Okeechobee, located in the southern central part of the state. The Everglades National Park is indicated in the lower part of the map.

Credit: Google Maps

annotated visible satellite image from May 5, 2007

Satellite image of Florida with labeled sea and lake breeze fronts.
annotated visible satellite image from May 5, 2007
Text description of the annotated visible satellite image from May 5, 2007 image.

The image is a satellite view of Florida and its surrounding regions, capturing sea and lake breeze fronts. It is in grayscale, showing cloud formations against the dark expanse of the ocean and land. Two prominent fronts are labeled as "Sea-Breeze Front." One stretches across the western coastline of Florida, and another is visible along the eastern coastline. A "Lake-Breeze Front" is labeled over central Florida, crossing the peninsula. The clouds appear as lighter, textured areas against the darker background, indicating variations in weather patterns.

Credit: NCAR

loop of visible satellite images from May 30, 2002 (0:14)

loop of visible satellite images from May 30, 2002
Text description of the loop of visible satellite images from May 30, 2002 video (0:14)

The image is a satellite view of a landmass surrounded by water, likely captured in grayscale. The landmass has an elongated shape, resembling a peninsula, with a narrow part at the north and expanding towards the south. Puffy, white clouds spread across the surface of the land, mostly concentrated along the center. The water surrounding the land appears dark, contrasting with the lighter clouds. The image appears to depict weather patterns over this geographic region.

Credit: NCAR

corresponding radar loop (0:12)

corresponding radar loop
Text description of the corresponding radar loop video (0:12)

The image is a radar map of Florida, displaying weather patterns. It shows a detailed outline of Florida with state borders drawn in orange. Various colors represent different levels of precipitation intensity, with patches of green, yellow, red, and blue scattered across the state. Green and yellow areas indicate lighter precipitation, primarily located in the northwestern parts of the state and along the northern border. Clusters of red, indicative of heavier rainfall, are concentrated in the central and southern regions of Florida. Blue areas show the least intense precipitation scattered throughout the map.

Credit: WSI Corporation

photo in Rocky Mountain National Park

Mountain landscape with rocky foreground and cloudy sky.
photo in Rocky Mountain National Park
Text description of the photo in Rocky Mountain National Park image.

The image depicts a mountainous landscape under a cloudy sky. In the foreground, there is a rocky terrain with sparse patches of grass. The midground features a series of ridges and peaks, varying in height. The mountains in the background are partially covered by a dense layer of white and gray clouds, suggesting an overcast day. The overall color palette consists of muted earth tones and shades of gray and blue, creating a calm and serene atmosphere.

Credit: Steve Seman @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

sequence of visible satellite images (0:03)

Text description of the sequence of visible satellite images video
Text description of the Text description of the sequence of visible satellite images (0:03)

The image is a satellite view of a geographical region showing parts of the western United States, including areas of clouds spread across several states. The clouds appear as white and gray patches against a darker background representing the land. State boundaries are outlined with thin white lines forming a grid-like pattern across the image. The clouds are more concentrated in the central area, thinning out towards the edges. In the lower right corner, a black box contains the white text "17Z."

Credit: NOAA

relief map cropped to the same view

Colorful topographic map with elevations in green, purple, and blue tones, including a blue patch suggesting water.
relief map cropped to the same view
Text description of the relief map cropped to the same view image.

The image is a colorful topographic map showing varying elevations and terrain features. The map predominantly features shades of green, purple, and blue to depict different terrain elevations. Some areas show rugged textures, indicating mountainous regions, while others are smoother and more uniform, representing plains or lower elevations. A distinct blue patch, possibly a water body, is visible on the left side. The top right and bottom corners gradually fade into red and pink hues, suggesting lower elevations. The overall orientation of the map appears to be diagonal, with geographical features casting intricate shadow patterns.

Credit: Johns Hopkins University

relatively few thunderstorms occur west of the Rockies

Map showing the number of thunderstorm days per year in the U.S. ranging from 5 to 100.
relatively few thunderstorms occur west of the Rockies
Text description of the relatively few thunderstorms occur west of the Rockies image.

The image is a color-coded map of the United States, illustrating the number of thunderstorm days per year across different regions. The main map covers the contiguous United States with two inserts displaying Alaska and Hawaii. The shades range from blue, indicating fewer thunderstorm days, to red, representing more frequent storms. The western U.S. features primarily blue tones with values from 5 to 30. Central regions transition through greens and yellows, indicating 20 to 50 days. The Southeast, especially Florida, is shaded in brown and red, suggesting up to 100 thunderstorm days. Alaska's inset shows mostly dark blue, while Hawaii has varying shades of blue and gray.

Credit: National Weather Service

 

Single-Cell Thunderstorms

image of radar reflectivity from 2055Z on June 14, 2015

A weather radar map depicting southeastern U.S. cloud coverage and precipitation.
image of radar reflectivity from 2055Z on June 14, 2015
Text description of the image of radar reflectivity from 2055Z on June 14, 2015.

The image is a weather radar map showing parts of the southeastern United States. It displays cloud coverage and precipitation levels using color-coded intensity scales. The states of Kentucky, Tennessee, North Carolina, South Carolina, Georgia, and parts of surrounding states are visible, outlined with blue lines. Cloud formations are shown as clusters of small white and light blue spots. Intense weather activity is depicted by bright colors such as yellow, green, and red scattered throughout the map, indicating areas of precipitation. The map has a gradient scale on the right side indicating precipitation intensity levels, with colors ranging from black (lowest) to white and bright colors (highest).

Credit: College of DuPage

entrainment

Diagram of airflow over cumulus clouds showing upward arrows and labeled
entrainment
Text description of the entrainment image.

The image shows a series of schematic arrows overlaid on a background of white cumulus clouds against a blue sky. At the bottom, a single orange and red upward arrow is contained within a dashed semicircle. Progressing upwards, each horizontal section includes an additional pair of blue arrows curving inwards toward the central upward arrow, indicating airflow. At the top section, the central arrow splits into three directions, inside a dashed semicircle, with the label "Entraiment" in blue text to the right. Each section is connected by dotted lines, forming a vertical, stepwise progression illustrating a concept related to cloud formation or airflow dynamics.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

depth of about one and a half times its diameter at the lifting condensation level

Diagram of a cumulus cloud with labels “Lifting Condensation Level,” “D,” and “1.5D,” showing upward air movement.
depth of about one and a half times its diameter at the lifting condensation level
Text description of the depth of about one and a half times its diameter at the lifting condensation level image.

The image shows a conceptual diagram of a cloud forming above a flat horizon. The cloud is large and white, resembling a cumulus cloud with a billowy texture. It has a wide base and narrows towards the top, tapering into a rounded peak. Below the cloud, there is a horizontal dashed line labeled "Lifting Condensation Level." Three orange arrows point upward from this line to the base of the cloud, indicating upward air movement. The base width of the cloud is marked "D," while the height from the dashed line to the top of the cloud is labeled "1.5D." The background is a gradient sky transitioning from light blue at the horizon to a deeper blue higher up. A strip of green at the bottom represents the ground.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

dominated by updrafts

Illustration of a towering cumulus cloud with upward orange arrows indicating updrafts.
dominated by updrafts
Text description of the dominated by updrafts image.

The image depicts a cumulonimbus cloud during its towering cumulus stage against a gradient blue-purple sky. The cloud is large, fluffy, and white, with a broad base and a rounded top, illustrating a vertically developing cloud. Several orange arrows are shown directing upwards from the bottom and through the cloud, indicating the presence of updrafts. The bottom of the image shows a horizontal green-brown line representing the ground.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

take on a slightly fuzzy or fibrous appearance

Cumulonimbus cloud with a distinctive glaciated top over a cityscape.
take on a slightly fuzzy or fibrous appearance
Text description of the take on a slightly fuzzy or fibrous appearance image.

The image depicts a large cumulonimbus cloud formation against a deep blue sky. The cloud rises dramatically from the horizon and culminates in a broad, flat top, characteristic of a glaciated cloud formation. The top of the cloud has a wispy, anvil-shaped appearance. A label "Glaciated Cloud Top" points to the upper part of the cloud. Below the cloud, a shadowed cityscape can be seen with a prominent tower in silhouette.

Credit: flickr.com / Pitero 86 / CC BY-SA 4.0

flat, spreading top of a cumulonimbus cloud

Harbor with boats and clouds labeled Anvil in the sky.
flat, spreading top of a cumulonimbus cloud
Text description of the flat, spreading top of a cumulonimbus cloud image.

The image shows a calm harbor scene under a clear blue sky with a few cumulus clouds labeled "Anvil" near the top of the image. Two groups of boats are docked on the left and right sides of the image. On the left, a large blue and white fishing boat is partially visible with its rigging extending upward. On the right, several smaller boats, including a sailboat with a tall mast, are docked close together. The foreground consists of a gravel shoreline with sparse greenery. In the distant background, a low, tree-lined horizon is visible. The water in the harbor is tranquil, reflecting some of the sky and boats.

Credit: Steve Seman @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

wind profile with weak shear

Vertical pressure scale with labels at different levels from 400 to 1000 mb.
wind profile with weak shear
Text description of the wind profile with weak shear image.

The image features a vertical pressure scale indicating atmospheric pressure levels against altitude, depicted in millibars (mb). A bold black vertical line runs from top to bottom with horizontal tick marks labeled at 400, 500, 700, 850, 925, and 1000 mb. To the left, a label reads "~6 km" near the 500 mb mark. On the right, the word "PRESSURE" is written vertically, followed by "(mb)" in smaller text. Several angled black lines extend from the vertical scale, aligned with each pressure level, illustrating changes or relationships at each point.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

gust front to race outward far from the storm

Illustration of storm cloud development with two stages: Mature and Dissipating, showing cloud structure, rain, and wind direction.
gust front to race outward far from the storm
Text description of the gust front to race outward far from the storm image.

This image is divided into two panels, labeled a) and b). The left panel illustrates the "Mature Stage" of a storm, featuring a large, towering cumulonimbus cloud with a flat top extending from the bottom to the top of the panel against a gradient blue sky. Beneath this cloud, there is heavy vertical rain depicted with blue lines, and a green, flat landscape with a subtle brown area below. Black arrows indicate weak, low-level winds moving towards the right of the image, while a blue arrow shows the movement of the storm. Text within this panel reads, "Weak, low-level winds relative to the moving storm allow the gust front to propagate unrestrained."

The right panel illustrates the "Dissipating Stage" of a storm. The cumulonimbus cloud appears smaller and less defined, with reduced rain shown. A new, smaller cumulus cloud is developing on the right side with upward orange arrows below it, indicating updrafts. The ground and sky colors are consistent with the left panel. A white arrow shows the movement of the storm towards the right. Text reads, "Developing new cumulus cloud."

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

 

Multicell and Supercell Thunderstorms

vertical wind profile typical of an environment with weak vertical wind shear

Vertical graph showing pressure levels from 400 mb to 1000 mb with a zigzag pattern.
vertical wind profile typical of an environment with weak vertical wind shear
Text description of the vertical wind profile typical of an environment with weak vertical wind shear image.

The image depicts a vertical linear graph representing atmospheric pressure and altitude. A thick vertical line on the right marks pressure levels, labeled at specific intervals: 400 mb, 500 mb, 700 mb, 850 mb, 925 mb, and 1000 mb. The labels are aligned vertically to the right of the line. On the left, another label marks an approximate altitude of 6 km. Short horizontal and angled lines extend to the left from each pressure mark, illustrating a zigzag pattern.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

wind profile typical of an environment with strong vertical wind shear

Vertical pressure scale from 400 to 1000 mb with wind barbs indicating speed.
wind profile typical of an environment with strong vertical wind shear
Text description of the wind profile typical of an environment with strong vertical wind shear image.

The image displays a vertical pressure scale diagram with a range from 400 to 1000 millibars (mb), marked along a vertical axis on the right side. Adjacent to each pressure level, various wind barbs indicate wind speed and direction. The topmost barb at 400 mb shows a single long line, while the subsequent levels display increasingly complex barbs, indicating changes in wind conditions. The 850 mb level has multiple barbs, reflecting higher wind speeds. On the left side, the height is marked as approximately 6 km alongside the 500 mb level. The word "PRESSURE" is written vertically next to the scale, with units labeled as (mb).

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

annotated image of regional radar reflectivity from 2225Z

Weather radar map showing multicell thunderstorms over the eastern United States.
annotated image of regional radar reflectivity from 2225Z
Text description of the annotated image of regional radar reflectivity from 2225Z image.

The image is a weather radar map showing parts of the eastern United States. The map outlines states with blue lines and indicates topographical details such as rivers and boundaries. The radar shows large patches of green, yellow, orange, and red, representing different intensities of precipitation moving eastward across the map. In the lower right, near the coast, a labeled circle highlights "Multicell Thunderstorms." A color scale on the right ranges from dark green to deep red, representing varying rainfall intensities. Weather radar images and data elements are scattered throughout the region, with more intense activity concentrated near the labeled area of thunderstorms.

Credit: College of DuPage

top-down view of radar reflectivity associated with a classic multicell thunderstorm

Illustration of a thunderstorm cell with colored bands indicating rain intensity and directional airflow arrows.
>top-down view of radar reflectivity associated with a classic multicell thunderstorm
Text description of the >top-down view of radar reflectivity associated with a classic multicell thunderstorm image.

The image illustrates a conceptual diagram of a thunderstorm cell. The primary focus is on a storm cell represented by concentric colored bands, indicating different precipitation levels. At the center is a red area marked as "Heavy Rain / Hail," surrounded by orange, yellow, and green bands labeled as "Light Rain." These bands signify the intensity of precipitation, transitioning from heaviest in the center to lighter outside. Blue arrows indicate the "Outflow (gust front)" around the storm's edge. Three curved yellow arrows labeled as "Inflow" point towards the storm center, suggesting the direction of incoming air. Two labels identify storm components: "Mature Cell" near the storm center and "New Cell" at the edge. A "Cloud Outline" in gray shades the overall storm area, with additional gray shading at the "Flanking Line" at the bottom left.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

hook echo

Radar image showing a storm with a hook echo marked in the upper right and another system in the upper left.
hook echo
Text description of the hook echo image.

The image is a meteorological radar display showing weather activity. It features colorful storm formations over a brown grid indicating geographical boundaries. The main focus is a storm cell in the upper right quadrant, marked by a distinct "hook" shape with varying intensity colors: red at the center, surrounded by yellow, green, and blue. This formation is encircled and labeled "Hook Echo." A second storm system with similar shapes is located in the upper left. Below, a cluster of light blue dots emanates from the bottom center, indicating radar interference or precipitation patterns. A color scale on the left measures intensity from 0 to over 80 dBZ.

Credit: Used with permission, Gibson Ridge Software / National Weather Service

mesocyclone

Diagram of a mesocyclone within a cumulonimbus cloud showing airflow patterns and rotation.
mesocyclone
Text description of the mesocyclone image.

The image is a diagram illustrating the structure of a mesocyclone within a cumulonimbus cloud. The background consists of a gradient sky transitioning from light to darker shades of blue towards the top. The cumulonimbus cloud is large and towering, with an anvil-shaped top extending horizontally. Arrows indicate airflow patterns, curving upwards into the cloud and circulating horizontally within it. Red arrows highlight the rotation within the cloud's center, labeled "Mesocyclone," and a red "L" representing low pressure. A dashed line to the left measures a distance of 5 kilometers. The land surface is depicted with a narrow strip of green at the bottom.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

 

Lake-Effect Snow and Snow Squalls

annual snowfall

Map showing average annual snowfall (inches) in the Great Lakes region from 1971 to 2000.
annual snowfall
Text description of the annual snowfall image.

The image is a map illustrating the average annual snowfall in inches across the Great Lakes region during the period from 1971 to 2000. Various shades of green and blue depict different snowfall ranges. Darker greens and blues indicate higher snowfall areas, while lighter greens denote lower snowfall. Snowfall figures range from 20 inches to 200 inches. The map is divided with contour lines representing distinct snowfall boundaries, with values labeled, showing 20-inch increments from 20 to 80 inches in lighter colors, and 100-inch increments in darker greens and blues. Lake shorelines and boundaries of the Great Lakes are clearly outlined. The map is labeled in the top right corner with the title "Average Annual Snowfall (inches) 1971-2000."

Credit: National Weather Service

Keweenaw Peninsula

Topographic map of Michigan and surrounding Great Lakes region, showing elevation and fault lines.
Keweenaw Peninsula
Text description of the Keweenaw Peninsula image.

The image is a topographic map of the Great Lakes region, focusing on the state of Michigan. The map is colored in various shades to depict elevation, with green representing lower elevations and red indicating higher terrain. The state of Michigan is prominently displayed, surrounded by the Great Lakes. Lake Michigan is shown on the left, with its long, narrow shape stretching north to south. To the northeast is Lake Huron, with a more irregular outline. The Keweenaw Peninsula extends into Lake Superior at the top left corner. Red lines denote political boundaries and fault lines, adding emphasis to the geographical divisions.

Credit: Johns Hopkins University

Japanese Islands of Honshu and Hokkaido

Map showing Japan, Korea, parts of China and Russia with labeled cities and seas.
Japanese Islands of Honshu and Hokkaido
Text description of the Japanese Islands of Honshu and Hokkaido image.

The image is a map highlighting regions of Japan, Korea, and parts of China and Russia. Japan is depicted in the center of the map with its four main islands: Hokkaido to the north, Honshu in the central region, Kyushu to the southwest, and Shikoku between Honshu and Kyushu. Major cities like Tokyo, Kyoto, Osaka, and Sapporo are labeled. Surrounding seas include the Sea of Japan to the west and the Pacific Ocean to the east. North Korea and South Korea are visible to the west, along with their capitals, Pyongyang and Seoul, respectively. Parts of eastern China and southern Russia are also included, with cities like Harbin and Vladivostok marked. The map is predominantly green for land and blue for bodies of water, with latitude and longitude lines for reference.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

schematic showing convective clouds growing as air cold air flows over a relatively warm lake

Diagram showing cold air moving over a warm lake, creating cloud formation and potential inland snowfall.
schematic showing convective clouds growing as air cold air flows over a relatively warm lake
Text description of the schematic showing convective clouds growing as air cold air flows over a relatively warm lake image.

The image is an illustrated diagram showing how cold, dry air interacts with a warm lake to create mixing in the boundary layer. The diagram includes a light blue water body labeled "Water Temperature (5°C)" at the bottom and light brown terrain on the left and right. A blue arrow near the surface depicts the movement of cold air labeled "Air Temperature (-5°C)" moving from left to right. Orange wavy lines represent rising heat and moisture fluxes from the lake. Above the lake, clouds are forming and moving with the wind. A dashed line labeled "Mixed Layer Inversion" ascends from left to right, illustrating the height of the mixing inversion increasing with distance over the lake. Snowflakes are depicted further inland, indicating potential snowfall. The background is a gradient of light to deep blue, representing the sky.

Credit: David Babb @ Penn State is licensed under CC BY-NC 4.0(opens in a new window)

nine-hour radar loop (0:17)

nine-hour radar loop
Text description of the nine-hour radar loop (0:17)

The image is a weather radar map displaying precipitation data over a specified geographic area. The map is delineated with a grid of white and red lines indicating county and state boundaries. Blue and green areas represent varying intensities of precipitation, with blue indicating lighter rain and green indicating moderate rain. Two concentric circles with labels "50 NM" and "100 NM" are drawn from a central radar location, showing the distance of detected precipitation. On the left side, a colored bar scales from light blue to dark pink, representing precipitation intensity levels from 5 dBZ to 80 dBZ. A compass rose in the top right corner is labeled "NEXLAB-College of DuPage."

Credit: College of DuPage