© Lorem ipsum dolor sit Nulla in mollit pariatur in, est ut dolor eu eiusmod lorem 2014
Weather Glossary
Jet Stream
The jet stream consists of ribbons of strong winds that circulate the earth. The strength of the stream
varies overtime and is split into two main flows. The subtropical Jet stream and the one that interests us
most the Polar jet stream. This stream effects our weather most. The Jet stream tends to be between
23000ft and 39000ft above sea level. The flow varies stops, splits and meanders across the atmosphere.
It’s direct location effects whether our weather will be unsettled or settled warm or cold. If we’re on the
south side of the stream it tend to be milder while if we’re on the north side cooler. The picture below
shows a fairly active polar jet stream to the south of the UK. Low pressures embedded in the flow moving
west to east.
The picture below show the jet splitting one branch going to the North while the other continues into
Africa. This is called blocking which I will deal with later. This will also mean that Low pressure to the South
West of the UK will swing North East and eventually stall and weaken as it loses the driving force of the Jet.
Sting Jet
The sting jet was only recently recognized after the October Storm 1987. The Sting jet forms at the bottom
of the hook in a low pressure system. It consists of very strong winds which luckily effect generally a very
small area. The sting starts about 3 to 4km above ground which slowly descends towards the ground.
Evaporative cooling increases the strength of the winds as the air becomes more dense sinking towards
the surface. Winds can reach up to 100mph
Sting jets form life span goes over four stages.
The first stage (A) see diagrams below is where pressure first starts to drop, and two narrow jets of air form
near the surface. Marked CJ for cold jet and WJ for warm jet. The low pressure system tends to be moving
with the warm jet therefore the warm jet produces the strongest winds.
The second stage (B) The Weather front Fractures shortly after the sting jet reaches the ground. The
strongest winds now occur.
The third stage (C) The sting Jet gradually grows larger over a period of a few hours.
The fourth stage (D) The Cold jet finally wraps around the Low Pressure centre L and catches up with the
Sting Jet. The worst of the winds are now over but strong gusts may still occur.
Picture courtesy of http://www.wettergefahren-fruehwarnung.de
© Lorem ipsum dolor sit Nulla in mollit pariatur in, est ut dolor eu eiusmod lorem 2014
Weather Glossary
Jet Stream
The jet stream consists of ribbons of strong winds that circulate the earth. The strength of the
stream varies overtime and is split into two main flows. The subtropical Jet stream and the one
that interests us most the Polar jet stream. This stream effects our weather most. The Jet
stream tends to be between 23000ft and 39000ft above sea level. The flow varies stops, splits
and meanders across the atmosphere. It’s direct location effects whether our weather will be
unsettled or settled warm or cold. If we’re on the south side of the stream it tend to be milder
while if we’re on the north side cooler. The picture below shows a fairly active polar jet stream
to the south of the UK. Low pressures embedded in the flow moving west to east.
The picture below show the jet splitting one branch going to the North while the other
continues into Africa. This is called blocking which I will deal with later. This will also mean that
Low pressure to the South West of the UK will swing North East and eventually stall and weaken
as it loses the driving force of the Jet.
Sting Jet
The sting jet was only recently recognized after the October Storm 1987. The Sting jet forms at
the bottom of the hook in a low pressure system. It consists of very strong winds which luckily
effect generally a very small area. The sting starts about 3 to 4km above ground which slowly
descends towards the ground. Evaporative cooling increases the strength of the winds as the air
becomes more dense sinking towards the surface. Winds can reach up to 100mph
Sting jets form life span goes over four stages.
The first stage (A) see diagrams below is where pressure first starts to drop, and two narrow jets
of air form near the surface. Marked CJ for cold jet and WJ for warm jet. The low pressure
system tends to be moving with the warm jet therefore the warm jet produces the strongest
winds.
The second stage (B) The Weather front Fractures shortly after the sting jet reaches the ground.
The strongest winds now occur.
The third stage (C) The sting Jet gradually grows larger over a period of a few hours.
The fourth stage (D) The Cold jet finally wraps around the Low Pressure centre L and catches up
with the Sting Jet. The worst of the winds are now over but strong gusts may still occur.
Picture courtesy of http://www.wettergefahren-fruehwarnung.de
© Lorem ipsum dolor sit Nulla in mollit pariatur in, est ut
dolor eu eiusmod lorem 2014
Weather Glossary
Jet Stream
The jet stream consists of ribbons of strong winds that circulate the
earth. The strength of the stream varies overtime and is split into two
main flows. The subtropical Jet stream and the one that interests us
most the Polar jet stream. This stream effects our weather most. The
Jet stream tends to be between 23000ft and 39000ft above sea level.
The flow varies stops, splits and meanders across the atmosphere. It’s
direct location effects whether our weather will be unsettled or settled
warm or cold. If we’re on the south side of the stream it tend to be
milder while if we’re on the north side cooler. The picture below shows
a fairly active polar jet stream to the south of the UK. Low pressures
embedded in the flow moving west to east.
The picture below show the jet splitting one branch going to the North
while the other continues into Africa. This is called blocking which I will
deal with later. This will also mean that Low pressure to the South
West of the UK will swing North East and eventually stall and weaken
as it loses the driving force of the Jet.
Sting Jet
The sting jet was only recently recognized after the October Storm
1987. The Sting jet forms at the bottom of the hook in a low pressure
system. It consists of very strong winds which luckily effect generally a
very small area. The sting starts about 3 to 4km above ground which
slowly descends towards the ground. Evaporative cooling increases
the strength of the winds as the air becomes more dense sinking
towards the surface. Winds can reach up to 100mph
Sting jets form life span goes over four stages.
The first stage (A) see diagrams below is where pressure first starts to
drop, and two narrow jets of air form near the surface. Marked CJ for
cold jet and WJ for warm jet. The low pressure system tends to be
moving with the warm jet therefore the warm jet produces the
strongest winds.
The second stage (B) The Weather front Fractures shortly after the
sting jet reaches the ground. The strongest winds now occur.
The third stage (C) The sting Jet gradually grows larger over a period of
a few hours.
The fourth stage (D) The Cold jet finally wraps around the Low
Pressure centre L and catches up with the Sting Jet. The worst of the
winds are now over but strong gusts may still occur.
Picture courtesy of http://www.wettergefahren-fruehwarnung.de
