MetO responce to Coastal Phenomenon

General club enquiries, talk about any subject you like.

Moderator: Club Moderators

Post Reply
Martyn Wimpenny
Mingling
Posts: 82
Joined: Fri Mar 19, 2010 4:12 pm
Location: Sunderland

MetO responce to Coastal Phenomenon

Post by Martyn Wimpenny »

Dear Martyn
Thank you for your email regarding a weather phenomenon observed on the UK North Sea/North East Coasts.
Having spoken to one of our meteorologists, there were some wave cloud observed on Monday July 2nd and atmospheric conditions on July 1st were fairly similar.
I’ve linked a video HERE from the 2nd of July. We suspect there were similar clouds on 1st but probably too small for the resolution of our satellite.
The UK has been experiencing very warm period of weather with temperatures in the mid 20s. The North Sea this time of year is about 13-15 C and so easterly winds made eastern parts of the country much cooler.
Critically there was a marked increase in temperature in lowest part of the atmosphere with cool maritime air near the surface and warmer air at say 1000-2000ft. The cooler air is more dense and so when displaced vertically in warmer less dense air it will experience a restoring force.
In the video the cool air over the surface of the north sea moves westward with the easterly wind. When this reaches the coastal barrier it rises upwards but immediately experiences the restoring force described above. This generates an atmospheric wave that propagates eastward for some distance and attenuates.
In the video the lines of cloud are areas when the air is rising (wave peaks) and the gaps are where the air is sinking (wave troughs). Below the turning motion of the air below the wave crests can force the wind to change direction. These regions can be associated with significant wind shear and occasionally turbulence. Similar phenomena is associated with lee-waves, atmospheric waves produced by air flowing over hills. Near the cliffs you could have an area of westward moving air from the wind colliding with eastward moving air from the wave to produce a region of light winds. There may have been a similar phenomena on the July 1st but the wave was confined to shallower depth and travelled less far out to shore.
I hope this information manages to answer your question, but if you have any further queries or need additional information, please contact our Weather Desk on +44 (0)1392 88 5680 where one of our advisors will be happy to help. The number is open 24 hours a day, every day of the year and it will help us if you can quote the reference number given above.
Kind regards,
Luke
Weather Desk Advisor

Met Office FitzRoy Road Exeter Devon EX1 3PB United Kingdom
Tel: 0370 900 0100 Fax: 0370 900 5050 Twitter: @metoffice
By phone or fax outside the UK Tel: +44 (0)1392 885680 Fax: +44 (0)1392 88 5681
Email: enquiries@metoffice.gov.uk or visit http://www.metoffice.gov.uk
Your personal details will be stored in our database. The information will not be passed to any third parties. Please advise us if you do not wish your details to be stored. The Met Office is a Trading Fund of the Department for Business, Energy and Industrial Strategy and is registered under the Data Protection Act 1998
This e-mail is intended for the addressee only. Its contents are provided "in confidence" and may be covered by contractual, legal or other privilege. If you are not the addressee, you may not use or copy it to any other person. If you receive this e-mail in error, then please contact the sender as detailed above.

Ref:MSG0210399_0P3w6P27Wrlnqo5OsEf3
Martyn Wimpenny
Mingling
Posts: 82
Joined: Fri Mar 19, 2010 4:12 pm
Location: Sunderland

Re: MetO responce to Coastal Phenomenon

Post by Martyn Wimpenny »

sorry the site will not accept the video -avi format
Post Reply