Great Storm Flashcards
Date?
October 15th (night) and October 16th (early morning)
What was the highest gust recorded and where?
122mph at Goneston Norfolk
What was the lowest pressure recorded?
951mb
What was the increase in pressure and in what time frame did it occur as the system moved north?
20mb in 3hrs
When were the highest gusts recorded in London and at what time?
94mph between 3am and 4am
Where did the storm first hit?
South coast of Cornwall and Devon
When did the storm hit the Midlands?
Just after midnight
In its final stage where did the storm reach?
Humber Estuary (east coast) at 5:30am
What is this storm described as?
A low frequency, high intensity storm
When did the last storm of this scale affect the UK?
1703
Where did the storm develop?
Bay of Biscay
What was the series of events?
S.W winds carrying warm,wet air from the N. Atlantic met N.E winds carrying cold air from the pole.
Depression deepened rapidly due to unusually warm sea surface temps within the bay + steep temp difference between air masses (season)
What are the 7 causes of the Great Storm?
Poor forecasting Depression String Jet Large pressure gradient Time of year Season Polar jet stream
Explain poor forecasting
Led to little preparation and intensified effects
Michael Fish at metoffice
Explain depression
Low pressure system formed over Bay of Biscay and was rapidly deepened by unusually warm sea surface temps
Explain ‘String Jet’
- Causes strength of storm to be boosted
- Cold air descends into storms high in the atmosphere
- Rain/snow falling into this jet evaporates and cools the air further
- This adds more energy
- Stronger winds
Term only came into use after 1987
Explain large pressure gradient
Large temp difference meant large pressure gradient and a faster flow of air
Explain time of year
Winter = N.pole receives less insolation whilst equator still receives large amounts. Caused temp difference and therefore large pressure gradient
Explain season
Autumn = broadleaf trees still had leaves meaning more damage to forests
Explain polar jet stream
Further south than normal meaning depression formed over N. France and S. England rather than Scotland
What were the ST social impacts?
- London = blacked out for 6 hours
- Suffolk = 360 schools closed
- Roads closed
- 18 killed (Br) 4 killed (Fr)
- 150+ injured
- Dover port closed
- Fire brigade = 6000 calls in 24 hours
- Gatwick airport was closed
- Falling debris + trees damaged 3 million houses/buildings
What were the LT social impacts?
- National grid sustained heavy damage
- Several thousand were left without power for 2 weeks
What were the ST environmental impacts?
- 15 million trees blown down
- Some areas lost 97% trees - loss of habitat for some + creation of habitat for others
What were the LT environmental impacts?
- Some plants benefitted as more light was able to reach the forest floor (less canopy albedo) meant they could grow
- A number of wild boars escaped and have since bred and established pops in woods across S.Eng
What were the ST economic impacts?
- Temporary price drop of hardwoods
- Trees meant roads/ transport links were closed and people were unable to reach work
- Very few deals struck on exchange/ money market as many were unable to travel to London
What were the LT economic impacts?
- Cost insurers 2 billion
- Damage to houses/ cars cost money for individuals and insurers
- Shanklin pier was destroyed meaning loss of employment and income for area (tourist attraction)
- Premiums increased next year
What was the ST national response?
- Mass media coverage - London
- 01:35 am = Metoffice issued warning to ministry of defence
- Emergency services dealt with 4 months worth of calls in one night
- Emergency services were warned
What as the LT national response?
- Metoffice
