5.5: Accessible Descriptions

Figure 5.2.1: A Blank Stüve Diagram

This is a Stüve diagram, a type of thermodynamic chart used in meteorology to analyze vertical profiles of the atmosphere. It displays how temperature varies with pressure and altitude, and is used to assess atmospheric stability, moisture, and wind data.

Axes:

• Temperature (°C) ranges from -80°C to +40°C in 10°C intervals.
• Pressure (mb) ranges from 1000 mb (near surface) to 100 mb at upper levels, in a logarithmic scale.
• Altitude (km) ranges from 0 km to 16 km, linearly spaced to correspond with pressure levels.

Grid Lines:

• Horizontal lines: Represent constant pressure levels.
• Vertical lines: Represent constant temperature values.
• Dry adiabats, sloped from lower left to upper right, showing the temperature change for rising or sinking unsaturated air parcels.
• Moist adiabats represent the temperature change for saturated air parcels during ascent or descent.
• Shallower slope lines are Isotherms, running vertically to track constant te mperature values. 
• Near-vertical dashed brown lines represent mixing ratio lines, indicating constant values of water vapor in grams per kilogram of dry air.

Figure 5.2.2: Stüve Diagram with lines

This is a Stüve diagram, labeled “Vertical Atmospheric Chart (Stüve),” used in meteorology to analyze vertical profiles of the atmosphere. It plots temperature versus pressure and altitude, and overlays highlighted examples of a dry adiabat and a moist adiabat.

Axes:

• Temperature in degrees Celsius (°C), ranging from -80°C to +40°C.
• Pressure in millibars (mb), ranging from 1000 mb (surface) at the bottom to 100 mb near the top, on a logarithmic scale.
• Altitude in kilometers (km), from 0 km to 16 km, increasing linearly upward.

Grid Lines and Background:

• Vertical lines: Constant temperature.
• Horizontal lines: Constant pressure (or height).
• Dry adiabats, sloping upward.
• Moist adiabats, also upward sloping  but more curved and variable.

Highlighted Features:

• A Dry Adiabat is shown, beginning at approximately 20°C and 1000 mb, extending upward to around -80°C and 250 mb. This line represents the temperature change of a rising unsaturated air parcel, cooling at about 10°C/km.
• A Moist Adiabat is also plotted, starting near the same surface point but curving slightly to the right as it rises. This line represents the cooling of a saturated air parcel, which cools more slowly with height because latent heat released by condensation reduces the parcel's cooling rate.

Figure 5.3.1: Average Annual Rainfall 

This map depicts the average annual precipitation across parts of Northern California, including the San Francisco Bay Area, based on data collected from 1900 to 1960. The geographic region extends from the coastline near San Francisco and Santa Cruz inland to Livermore, Tracy, and parts of the Central Valley.

Map Overview:

• City names such as San Francisco, Oakland, San Jose, Fremont, Sunnyvale, Santa Cruz, and Livermore are labeled on the map for spatial reference.
• The base map uses colored contours to indicate zones of average annual precipitation in inches.
• The map legend on the right categorizes precipitation into 13 ranges, from 3–4 inches up to 125 inches per year.

Precipitation Ranges and Patterns:

The color-coded contour regions represent the following precipitation ranges (in inches):

• 3–4
• 5–6
• 7–8
• 9–10
• 11–15
• 16–20
• 21–25
• 26–30
• 31–50
• 51–125

Key patterns:

• Lowest precipitation areas (3–10 inches per year) are concentrated in valleys and interior lowlands, especially near San Jose, Fremont, and parts of the East Bay.
• Moderate precipitation zones (15–25 inches) appear in much of the San Mateo Peninsula, Redwood City, and parts of the inland hills near Livermore and Concord.
• Higher precipitation zones (over 30 inches) are found along the coastal mountains, including the Santa Cruz Mountains west of San Jose and near Santa Cruz and parts of the coastal Pacific slope.
• A small area near Big Basin or the Santa Cruz Mountains may reach over 50 inches per year.

Figure 5.3.2: Topography of the San Francisco Bay Area

This is a topographic map of central coastal California, with a focus on the San Francisco Bay Area and adjacent terrain. The map uses shaded relief to represent elevation and terrain texture, but does not include contour lines, colors, or elevation labels beyond land shading.

Geographic Scope:

• Several prominent cities are labeled, including San Francisco (located in the northwest corner of the map, near the ocean), San Jose (in the center of the map, inland from the bay), Santa Cruz (in the southwest portion of the map, near the coast), and the Pacific Ocean to the west.
• The San Francisco Bay is visible, extending inland toward the east and splitting into multiple channels.  

Topographic Features:  

• The Santa Clara Valley, where San Jose is located, is surrounded by mountainous terrain.
• The Santa Cruz Mountains lie to the west of San Jose and extend south toward Santa Cruz.
• The Diablo Range lies to the east of the Santa Clara Valley.
• The elevated terrain is represented by darker-shaded areas that form ridges and valleys.
• Lowland valleys and plains are shown in lighter shading and are mainly located around San Jose and east of San Francisco Bay.

Figure 5.4.1: Weather Balloon data for Dallas, TX

This is a Stüve diagram for Fort Worth, Texas (station ID: 72249), valid at 00Z on May 21, 2019, providing an atmospheric profile of:

• Observed environmental temperature (black line)
• Dew point temperature (black dashed line)
• Theoretical parcel ascent curve (red line)

Axis Information:

• Vertical Axis (left): Atmospheric pressure in millibars (mb), decreasing from 1000 mb at the bottom to 100 mb at the top. Corresponding altitude in meters is labeled alongside, ranging from 0 to 16,440 meters (~54,000 feet).
• Vertical Axis (right): Altitude in kilometers (km), ranging from 0 to 16 km.
• Horizontal Axis: Temperature in degrees Celsius, ranging from -80°C to +40°C.

Key Features:

CAPE (Convective Available Potential Energy):

• Labeled on the right side of the diagram at the 300 mb pressure level, corresponding to an altitude of approximately 9.5 km (31,200 feet).
• CAPE is the region where the red parcel path is to the right of the environmental temperature line (black), meaning the parcel is warmer and buoyant relative to its surroundings.
• In this diagram, CAPE exists from roughly 650 mb (~3.8 km or 12,500 ft) up to 300 mb (~9.5 km or 31,200 ft).

CIN (Convective Inhibition):

• Highlighted by a blue oval around the 700 to 850 mb pressure levels, corresponding to an altitude range of approximately 1.5 to 3 km (5,000 to 10,000 ft).
• CIN is the region where the parcel path is cooler than the environment (i.e., the red line is left of the black line), meaning the parcel is negatively buoyant and will resist upward motion unless forced.

Figure 5.4.2: Weather Balloon data for Topeka, Kansas

This is a Stüve diagram for Topeka, Kansas, valid at 00Z on May 29, 2019. It provides a vertical atmospheric profile of temperature, dew point, and parcel trajectory for assessing atmospheric stability.

Axes and Grid:

• Vertical axis (left): Pressure in millibars (mb), decreasing from 1000 mb at the bottom (surface) to 100 mb at the top, corresponding approximately to altitudes from 0 to 16.4 km or 0 to 54,000 feet (labels in both meters and feet).
• Vertical axis (right): Altitude in kilometers (0 to 16 km).
• Horizontal axis: Temperature in degrees Celsius, ranging from -80°C to +40°C.
• Blue vertical lines: Constant temperature (isotherms).
• Green sloped lines: Dry adiabats (constant potential temperature).
• Purple curved lines: Moist adiabats (for saturated ascent).
• Dashed brown lines: Mixing ratio lines (constant moisture content).

Plotted Lines:

• Black jagged line (right side): Environmental temperature profile.
• Black jagged line (left side): Dew point temperature profile (moisture).
• Red smooth line: Parcel path, showing theoretical temperature of a surface air parcel if lifted.

Stability Interpretation:

• The parcel path (red) closely follows the environmental temperature (black) throughout the troposphere, indicating a neutrally stable or weakly unstable atmosphere.
• There is no clear region of significant Convective Available Potential Energy (CAPE) where the red line is warmer than the environment, suggesting low thunderstorm potential.
• No obvious Convective Inhibition (CIN) region is present either, as the surface parcel follows the environment without major suppression.

Approximate Altitudes of Interest:

Feature	Pressure (mb)	Approx. Altitude (km)	Description
Surface	1000	0	Starting level of the sounding
Tropopause (near 200 mb)	200	~12	Near the top of the diagram, no CAPE is evident
LCL (not labeled)	~850–900	~1.2	Expected lifting condensation level, near the surface

Figure 5.4.3: Severe Weather Report on May 28, 2019 

This is a NOAA/NWS Storm Prediction Center map displaying filtered severe weather reports across the United States for May 28, 2019. The map includes tornadoes, damaging wind events, and hail reports, as recorded by the National Weather Service.

General Layout:

• The map covers the contiguous U.S. with state boundaries outlined.
• The location of Topeka, Kansas, is labeled near the central part of the map.
• Symbols are used to denote different types of storm reports:
  • Tornadoes
  • Damaging wind (including high wind reports)
  • Hail (including large hail over 2 inches in diameter)

Storm Report Totals:

• Tornado Reports: 35
• Wind Reports: 136 total, including 1 high wind report (gusts ≥ 65 knots or ~75 mph)
• Hail Reports: 263 total, including 36 large hail reports (hail ≥ 2 inches in diameter)
• Total Reports: 434  

Geographic Distribution of Reports:  

• A dense band of storm reports stretches from eastern Kansas and northern Oklahoma eastward through Missouri, Illinois, Indiana, Ohio, and into the Northeast U.S., including Pennsylvania and New York.
• The highest concentration of tornado reports is near Topeka, Kansas, and the surrounding region.
• Hail reports are widespread across the central U.S., with many reports from Kansas, Missouri, and farther east.
• Wind damage reports (including the one high wind report) are scattered along the same path from the Plains through the Northeast.
• A few isolated storm reports also appear in Oregon, Texas, and parts of the Southeast U.S.