How do you read a weather map, its isobars, front symbols and a station model?
Interpret weather maps, including isobars, front symbols, and the station model (temperature, dewpoint, pressure, wind, sky cover), and use them to forecast (Virginia 2018 Earth Science SOL ES.1 and ES.9).
A SOL-level answer on weather maps for the Virginia Earth Science EOC: reading isobars and what close isobars mean, the symbols for cold, warm, stationary and occluded fronts, how to decode a station model (temperature, dewpoint, pressure, wind direction and speed, sky cover), and using maps to forecast, with worked exam questions.
Reviewed by: AI editorial process; not yet individually human-reviewed
Have a quick question? Jump to the Q&A page
Jump to a section
What this topic is asking
Virginia Earth Science SOL standards ES.1 and ES.9 expect you to read a weather map and a station model, a core meteorology skill. The EOC tests this with isobar items (what close isobars mean), front-symbol identification, station-model decoding (temperature, dewpoint, wind, sky cover), and short forecasting items (what weather is coming). Like the topographic map, the weather map is a high-value stimulus that turns up repeatedly.
Isobars
Front symbols
Each front type has a standard symbol you must recognize:
- Cold front: a line with triangles (often blue) pointing in the direction the front moves; brings brief heavy showers or storms, then cooler air.
- Warm front: a line with half-circles (often red) pointing the way it moves; brings steady light precipitation, then warmer air.
- Stationary front: triangles and half-circles on opposite sides of the line; the front is stalled.
- Occluded front: triangles and half-circles together on the same side (often purple); a cold front has overtaken a warm front.
The station model
To read a station model, take each piece in turn: temperature and dewpoint on the left (a small gap means near-saturation, likely clouds or rain), pressure on the upper right, the shaded fraction of the circle for cloud cover, and the wind shaft and barbs for direction and speed.
Forecasting from a map
Across the continental United States, weather systems generally move from west to east (carried by the prevailing westerlies). So to forecast a place's weather, look at what lies to its west: an approaching low or cold front to the west means storms are likely soon; a high to the west means fair weather is on the way. Combine the front type, the pressure system and the wind to predict the change.
Try this
Q1. What do closely spaced isobars on a weather map indicate? [1]
- Cue. A steep pressure gradient and therefore strong winds.
Q2. On a station model, where is the dewpoint located, and what does a small temperature-dewpoint gap suggest? [2]
- Cue. The dewpoint is at the lower left; a small gap means the air is near saturation (high relative humidity), so clouds or precipitation are likely.
Exam-style practice questions
Practice questions written in the style of VDOE exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
VA Earth Science SOL 2023 (style)1 marksOn a weather map, isobars (lines of equal pressure) are packed very close together over a region. What does this indicate? (A) calm conditions. (B) strong winds. (C) high temperatures. (D) clear skies.Show worked answer →
A 1-point multiple-choice item on isobars.
The correct answer is B. Closely spaced isobars mean the air pressure changes sharply over a short distance (a steep pressure gradient), and a steep pressure gradient drives strong winds. Widely spaced isobars mean a gentle gradient and light winds. Isobar spacing shows the wind strength, not temperature (C) or sky cover (D) directly.
The test rewards the rule: close isobars mean strong winds, like close contour lines meaning a steep slope.
VA Earth Science SOL 2024 (style)2 marksA station model shows a temperature of 68, a dewpoint of 66, mostly cloudy sky cover, and a wind shaft pointing from the northeast. (a) State the relationship between the temperature and dewpoint and what it suggests. (b) State the wind direction.Show worked answer →
A 2-point item on decoding a station model.
(a) 1 point: the temperature (68) and dewpoint (66) are very close (only 2 degrees apart), so the air is near saturation (high relative humidity), suggesting cloudy or rainy conditions, which matches the mostly cloudy sky cover shown.
(b) 1 point: the wind is from the northeast (winds are named for the direction they blow from, shown by the shaft pointing into the station circle from that direction).
Markers reward linking a small temperature-dewpoint gap to near-saturation in (a) and reading the wind as from the northeast in (b).
Related dot points
- Describe air masses and the weather at cold, warm, stationary and occluded fronts, and explain how thunderstorms, hurricanes and tornadoes form (Virginia 2018 Earth Science SOL ES.9).
A SOL-level answer on weather systems for the Virginia Earth Science EOC: how air masses get their properties from their source region, the weather at cold, warm, stationary and occluded fronts, and how thunderstorms, hurricanes and tornadoes form, including their hazards in Virginia, with worked exam questions.
- Explain how temperature affects air pressure and density, how wind blows from high to low pressure, the Coriolis effect, and local winds such as land and sea breezes (Virginia 2018 Earth Science SOL ES.8).
A SOL-level answer on air pressure and wind for the Virginia Earth Science EOC: how temperature controls air density and pressure, why wind blows from high to low pressure, the difference between rising low-pressure systems (stormy) and sinking high-pressure systems (fair), the Coriolis effect, and land and sea breezes, with worked exam questions.
- Explain humidity, relative humidity and dew point, describe how clouds form when air cools to saturation, and identify the main cloud types and forms of precipitation (Virginia 2018 Earth Science SOL ES.8 and ES.9).
A SOL-level answer on atmospheric moisture for the Virginia Earth Science EOC: humidity and relative humidity, the dew point and saturation, how clouds form when rising air cools and condenses on nuclei, the main cloud types (cumulus, stratus, cirrus), and the forms of precipitation, with worked exam questions.
- Organize, analyze and interpret data using tables and graphs (line, bar, scatter), identify trends and the relationship between variables, and calculate the rate of change and percent (Virginia 2018 Earth Science SOL ES.1).
A SOL-level answer on data and graphs for the Virginia Earth Science EOC: choosing the right graph type, putting the independent variable on the x-axis, reading and describing trends, interpolating and extrapolating, calculating rate of change and percent deviation, and what a gradient on a map means, with worked exam questions.
- Distinguish weather from climate, explain the factors that control climate (latitude, elevation, water, ocean currents, prevailing winds), and describe the evidence for climate change and the enhanced greenhouse effect (Virginia 2018 Earth Science SOL ES.9).
A SOL-level answer on climate for the Virginia Earth Science EOC: the difference between weather and climate, the factors that control climate (latitude, elevation, proximity to water, ocean currents, prevailing winds), the evidence for climate change, the enhanced greenhouse effect, and its impacts on Virginia, with worked exam questions.
Sources & how we know this
- 2018 Science Standards of Learning (Earth Science) — Virginia Department of Education (2018)
- SOL Practice Items (All Subjects) — Virginia Department of Education (2024)