Topic: Depressions

Fieldwork Suggestions for Independent Investigations

Post date 21 November 2022

Some ideas, data sources and guidance for students wishing to include weather measurements in their NEA or EPQ.

Updated November 2022

Depressions: Case Study Template and Storm Eunice Example

Post date 3 March 2022

Download editable worksheet.

This can be used to create a case study of a named depression in the UK. Below, we have given an example of how the worksheet could be used to create a case study of Storm Eunice.

Depressions are low pressure weather systems which bring rain, wind and sometimes snow to the UK. They are responsible for much of our extreme weather. A depression is easily recognisable on weather charts and satellite images. It has low pressure in the centre with warm, cold and occluded fronts and a hook shaped cloud.

In the UK, storms have been given names since 2015. A storm is named if it is likely to have a significant impact on the UK or Ireland.

Write down the names of any recent storms you can remember. Eunice
Use the Met Office storm centre index to discover the date that one of those storms had an impact on the UK/ Ireland (if your storm isn’t in the current year, scroll to the bottom of the page to the Related Links section for previous years).

Storm Name: Eunice Date: 18th February 2022

Now download the weather charts for the storm.

In the bottom left of the page, where is says ‘Archiv – Basistermin, enter the date of the storm in the format day – month – year

3) Copy and paste the weather map onto this document.

4) Put a red circle around the centre of the storm. This is marked by a cross and the pressure value at the centre of the storm is given.

Now use the single forward arrow to advance the chart by 6 hours.

5) Copy and paste the weather map onto this document.

6) Put a red circle around the centre of the storm

Now use the single forward arrow to advance the chart by 6 hours.

7) Copy and paste the weather map onto this document.

8) Put a red circle around the centre of the storm

9) Now complete the table using information from your three weather maps:

Winds rotate around a depression in an anticlockwise direction, following the pressure contours.

10) Use ‘insert’ and ‘shapes’ to add arrows showing the wind direction around the storm to the first of your weather maps.

In addition to naming storms, sometimes colour coded weather warnings are given. The colour of the warning depends on a combination of how much damage the storm is expected to do, and how likely that damage is. So a storm that is very likely to cause a lot of damage is given a red warning, but a yellow warning could mean that a storm is either very likely to cause a bit of damage, or unlikely to cause a lot of damage.

11) Go back to the Met Office storm centre https://www.metoffice.gov.uk/weather/warnings-and-advice/uk-storm-centre/index and click on your storm’s name – this should give you a summary sheet about your storm. Scroll through it – were any weather warnings issued? List them below, or write ‘none’.

Extension

Use the Met Office summary sheet you just opened, or BBC news https://www.bbc.co.uk/news to write a paragraph about the impacts of your storm.

Storm Eunice had significant impacts, including four fatalities and significant wind damage. However, with weather warnings issued almost a week in advance, the precautionary measures people were able to take, for example closing schools, meant that damage was minimised.

Pressure and Rainfall

Post date 8 March 2021

Investigating the Link Between Between Pressure and Rainfall

Teachers Notes

Here is some data collected by a weather station on the outskirts of Edinburgh, at the start of 2019.

Date	Atmospheric Pressure (hPa)	Rainfall (mm)
10/12/2018	1025	0.0
11/12/2018	1020	0.0
12/12/2018	1019	0.0
13/12/2018	1022	0.0
14/12/2018	1017	0.0
15/12/2018	988	1.0
16/12/2018	1005	5.1
17/12/2018	1005	0.3
18/12/2018	996	1.5
19/12/2018	995	0.3
20/12/2018	995	0.5
21/12/2018	1000	0.5
22/12/2018	1014	0.0
23/12/2018	1027	0.0
24/12/2018	1032	0.3
25/12/2018	1026	0.3
26/12/2018	1023	0.0
27/12/2018	1023	0.0
28/12/2018	1022	0.0
29/12/2018	1030	2.3
30/12/2018	1030	0.3
31/12/2018	1026	0.0
01/01/2019	1044	0.0
02/01/2019	1043	0.0
03/01/2019	1041	0.0
04/01/2019	1039	0.0
05/01/2019	1034	0.0
06/01/2019	1031	1.0
07/01/2019	1024	0.0
08/01/2019	1033	0.0
09/01/2019	1031	0.0

Using this data, draw a graph of rainfall against pressure.

Now use this information to complete the following sentences:

The most it rained in one day was _______________mm.

It didn’t rain at all on ____________ days.

The highest pressure recorded was ______________hPa (a hPa is the same as a millibar).

The lowest pressure recorded was _______________hPa.

Does it always rain when the pressure is low? Use figures to justify your answer.

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Does it ever rain when the pressure is high? Use figures to justify your answer.

Many weather apps assume that if the pressure is low, it will rain. Does your graph justify this assumption?

Extension:

Here are the weather maps for 4 of the days when it rained: the first 3 show when the pressure was low and the 4^th shows when the pressure was high and it rained.

Passage of a Depression – Animation

Post date 1 March 2021

Worksheet to accompany the animation.

Depressions, Anticyclones and Fronts

Post date 11 December 2020

Passage of a Depression – interactive animation

Worksheet to accompany the animation.

For 11+

Depressions from our Weather and Climate teacher’s guide

Pop-up depression

Cold and Warm fronts activities for differentiation and revision

Finding weather features on a simple synoptic chart

Red sky at Night, Shepherd’s Delight worksheet and Teacher’s Notes – a resource looking at how our prevailing wind direction means this saying is largely true.

Depressions Taboo

Depressions case study template and example of Storm Eunice – collect and annotate weather charts for a named storm, weather warnings and impacts of the storm.

For 14+

Weather systems PowerPoints and cross section practice

Using WOW data to investigate a depression passing across the UK with worksheets for students including isoline drawing practice.

Anticyclones, depressions and fronts with student worksheets

Depressions and anticyclones with a synoptic chart exercise

A case study of orographic rainfall in Scotland.

What is the weather? Work out what the weather is like at several UK locations based on some simplified weather maps.

Interpreting weather charts basic information on synoptic charts, with Isotherm map exercise and Synoptic chart exercise.

Isotherm and Isobar drawing exercise based on a depression on our contour resources page.

For 16+

Weather charts
Weather systems
Weather systems tutorial videos

17. Depressions

Post date 19 November 2020

Weather and Climate: a Teachers’ Guide

Pathway: Extending Weather

Pressure and Wind – Water in the Atmosphere – Anticyclones – Depressions

Lesson overview: In this lesson we look at the causes of Low pressure systems and the weather they bring to the UK.

Depressions or low pressure weather systems, bring most of the ‘normal’ and ‘extreme’ weather that we experience in the UK. Driven by rising air, they mix colder and warmer air masses, forming fronts where these meet and bringing a predictable progression of weather as they pass over the UK. Their approach is typically first signalled by high cirrus cloud, which eventually develops into rain-bearing stratus. Once this passes there may be higher temperatures and less precipitation for a while, before towering cumulonimbus clouds arrive bringing heavy rainfall followed by lower temperatures and scattered showers.

Learning objectives:

To understand what low pressure is.
To know what weather a depression system brings to the UK.
To be able to draw and explain weather fronts.
To understand how weather changes in the UK as a depression passes over

Key Teaching Resources

Depressions PowerPoint
Depressions PowerPoint (easier)
Depressions Worksheet
Depressions Worksheet (easier)
Depressions Homework
Depressions animation worksheet
Pop-up Depression

Teacher CPD/ Extended Reading

Depressions_More for Teachers

Alternative or Extension Resources

Further resources for teaching about depressions, anticyclones and fronts.

Template worksheet for creating a case study of a named storm – with Storm Eunice as a worked example.

Alternatively … you could get today’s weather chart and ask students to write a forecast for a place in the UK … or capture the weather forecast, from YouTube or similar, without the sound and ask students to write (and present) the commentary to go with it.

Weather and Climate: a Teachers’ Guide

18. Microclimates

19. Urban Climates

20. Tropical Cyclones

Post date 19 November 2020

Identify the weather features on the synoptic (weather) chart below:

Cold Front

Warm Front

Highest pressure

Depression

Anticyclone

Isobar

Occluded Front

Strong Wind

Light Wind

Lowest Pressure

Advanced

Northerly Wind

Northwesterly Wind

Southwesterly Wind

(hint the clouds in the images below are cirrus, cumulonimbus, cumulus and nimbostratus)

Pop-up Depression

Post date 19 November 2020

Print, cut-out and fold along the lines to make a 3D model of a depression.

Passage of a Depression – Account

Post date 19 November 2020

Vertical Section through a Warm Front of an Active Depression

Passage of a depression

Use the following help sheet to write a fictional story about the passing of a depression. Imagine you are in the field taking observations and measurements. You should use all the statements included below.

Coming of the warm front	At the warm front	Within the warm sector	At the cold front	Within the cold sector
Barometer – shows pressure is falling	Barometer – continues to show the pressure is falling.	No significant changes on the barometer.	Suddenly the pressure on the barometer begins to rise.	Pressure continues to rise.
Thermometer – shows the temperature is steady	Thermometer – shows the temperature is rising. Feeling a little sticky in this heavy coat!	Still quite mild.	Time for a hat, and to button up that coat, the temperature is falling, it’s becoming chilly.	It remains cold.
Cirrus clouds high in the sky, they begin to descend and thicken becoming altostratus.	Becomes darker, the clouds are low and cover the sky like blankets – nimbostratus.	Starting to see breaks in the cloud, a little drizzle now – nothing heavy.	Angry looking clouds, towering and grey, begin to form – cumulonimbus.	The clouds have thinned out now – some cumulus.
No need for the umbrella yet!	Time to get out the umbrella, continuous heavy rain.	A steady breeze, nothing too uncomfortable.	Heavy rain! Is that thunder I hear?	A few showers.
Slight increase in wind speed.	The wind is much stronger now – struggling to hold onto my umbrella.		Struggling to stay on my feet, as I’m battered by the strong winds.	Time to go home I think!

Drawing Pressure and Temperature Contours (Intermediate)

Post date 19 November 2020

Drawing Temperature and Pressure Contours

Lines of equal temperature – temperature contours, are called isotherms.

In this exercise, the task is to draw the 8.5°C, 6.5°C and 2.5°C isotherms. The 10.5°C and 4.5°C isotherms have already been drawn to help.

Start with the 8.5°C isotherm. This is the line which has everything warmer than 8.5°C on one side of it, and everything colder than 8.5°C on the other side. You could use a coloured pencil to colour in the dots for everywhere that is warmer than 8.5°C. Your isotherm is then the line which separates your coloured dots from the uncoloured ones.

Next, try the 2.5°C isotherm. For this, you could use a different colour to shade the dots for everywhere that is colder than 2.5°C.

Lastly, draw the 6.5°C isotherm. This will be very close to the 4.5°C isotherm in places, so be careful! To help with this, you could use a 3rd colour to shade the places where the temperature is 7 or 8°C, and a 4th colour to shade the places where the temperature is 5 or 6°C. Your line will divide the two.

Remember, contours can never touch or cross each other (it can’t be 8.5°C and 6.5°C at the same place!). The line should start and finish at an edge of the page.

Lines of equal pressure – pressure contours, are called isobars.

In this exercise, the task is to draw the 1016, 1012, 1008 and 1004mb isobars. However, to save space on the map, the pressure values have been recorded in shorthand – so 9 or 09 is short for 1009, 11 is short for 1011 etc.

On this map, we have some extra clues – these weather observations indicate the wind speed by the tail on the symbol. The wind is blowing from the tail of the arrow to the centre (the bars on the tail of the arrow tell you the wind speed) so –o is a wind blowing from the west to the east, or o—is a wind blowing from the east to the west. The wind tends to blow along the pressure contours, so your contours need to be roughly parallel to the tails on the closest weather symbols.

Start with the 1016mb contour. Where on the map are there places where the pressure is higher than that? If it helps, colour in those symbols where the value is greater than 16. Your pressure contour needs to divide those symbols from the others.

Now use a different colour to shade the symbols where the pressure value is 13, 14 or 15. Can you now draw the 1012mb isobar?

Again, use a different colour to shade the symbols where the pressure value is 9, 10 or 11. Can you now draw the 1008mbar contour?

Lastly, is there anywhere where the pressure is under 1004mb? If so, draw the 1004mb contour to separate off that observation from the others.

These two maps both correspond to the same weather situation. Can you work out what is going on?

Clues:

– Where is the pressure lowest?

– How is the wind direction changing across the map?

– In general, where is the temperature lower and where is it higher?

– Where is the temperature changing most rapidly? Remember that a front is where cold and warm air meets. You can use the wind information on the second map to see where the cold air is pushing into the warm air (a cold front) or whether the warm air is pushing into cold air (a warm front).

A guide to collecting weather data

Passage of a depression

Weather and Health/ Behaviour

Urban Climates

Community resilience to extreme weather

Local microclimate

Factors affecting rainfall:

Red Sky at Night

Snow

Sky Colour

Weather and Flooding

Sea level

Land and Sea breezes, sea breeze front

Air Masses

General resources

Download editable worksheet.

Extension

Passage of a Depression – interactive animation

For 11+

For 14+

For 16+

Weather and Climate: a Teachers’ Guide

Weather and Climate: a Teachers’ Guide

18. Microclimates

19. Urban Climates

20. Tropical Cyclones

Passage of a depression

Drawing Temperature and Pressure Contours

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