uk.sci.weather (UK Weather) (uk.sci.weather) For the discussion of daily weather events, chiefly affecting the UK and adjacent parts of Europe, both past and predicted. The discussion is open to all, but contributions on a practical scientific level are encouraged.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old December 4th 04, 11:33 PM posted to uk.sci.weather
external usenet poster
 
First recorded activity by Weather-Banter: Jul 2003
Posts: 643
Default [WR]Lee slope gale Copley

Hi, all,

The Pennine lee wave has been active this evening and the rise and fall
of the wind is very noticeable on the Davis graphs. Rising from F2 at
1800Z to a peak 10 minute mean of 39mph(F8) from 1940Z - 1950Z, max gust
51mph at 2000Z back down to F3 at 2200Z.

It has happened several times in the past few days on the SW'ly flow.

--
Ken Cook, Copley (5miles north of Barnard Castle), County Durham.
830ft
http://mysite.wanadoo-members.co.uk/copley
(MO climat. site updated before 10Z and 19Z daily)
kencookATcopleydurham.freeserve.co.uk
(All times GMT)





---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.805 / Virus Database: 547 - Release Date: 03/12/04



  #2   Report Post  
Old December 5th 04, 11:17 PM posted to uk.sci.weather
external usenet poster
 
First recorded activity by Weather-Banter: Jul 2003
Posts: 170
Default [WR]Lee slope gale Copley

In message , Ken Cook
writes
Hi, all,

The Pennine lee wave has been active this evening and the rise and fall
of the wind is very noticeable on the Davis graphs. Rising from F2 at
1800Z to a peak 10 minute mean of 39mph(F8) from 1940Z - 1950Z, max gust
51mph at 2000Z back down to F3 at 2200Z.

It has happened several times in the past few days on the SW'ly flow.

Would that have affected us down here? We've certainly been alternating
between relatively sudden, quite strong winds, and very calm spells.
--
Anita Evans
North Cumbria
(anita[at]ra.evans.clara.co.uk to reply by e-mail)
  #3   Report Post  
Old December 6th 04, 07:04 AM posted to uk.sci.weather
external usenet poster
 
First recorded activity by Weather-Banter: Sep 2004
Posts: 457
Default [WR]Lee slope gale Copley

Anita Evans wrote in message

Would that have affected us down here? We've certainly been alternating
between relatively sudden, quite strong winds, and very calm spells.


Ken is of course in the lee of the Pennines in a SW'ly so the abruptly
changing winds in lee wave conditions are to be expected.

A very crude but effective way of thinking of things goes like this:
If a location happens to be at the bottom of the trough of the wave,
then the air is "squashed" against the ground so the wind speed
increases. If the wavelength changes - as it can easily do in lee
wave conditions - that same location might then be under the crest of
the wave, so surface wind is much reduced (can even be reversed)

In your location Anita to the west of the Pennines, in SW winds, this
won't apply to you with respect to wave generated by the Pennines.
But you could easily experience such a phenomenon caused by the hills
upwind of you, eg the Lake District. It happens that the Pennines are
a linear feature (simplified) whereas the Lakes are a far more
"jumbled" set of mountains. Thus the wave generated by the Pennines
is a little more organised.

Jack
  #4   Report Post  
Old December 6th 04, 11:06 PM posted to uk.sci.weather
external usenet poster
 
First recorded activity by Weather-Banter: Jul 2003
Posts: 170
Default [WR]Lee slope gale Copley

In message , Jack
Harrison writes
Anita Evans wrote in message

Would that have affected us down here? We've certainly been alternating
between relatively sudden, quite strong winds, and very calm spells.


Ken is of course in the lee of the Pennines in a SW'ly so the abruptly
changing winds in lee wave conditions are to be expected.

I'm pretty sure we have been feeling the effects of being east of the
Lakeland fells as you say. It seems more generally breezy now, rather
than the stop start winds we've been having.
--
Anita Evans
North Cumbria
(anita[at]ra.evans.clara.co.uk to reply by e-mail)
  #5   Report Post  
Old December 7th 04, 09:33 AM posted to uk.sci.weather
external usenet poster
 
First recorded activity by Weather-Banter: Jul 2003
Posts: 643
Default [WR]Lee slope gale Copley

"Anita Evans" wrote in message
...
In message


I'm pretty sure we have been feeling the effects of being east of the
Lakeland fells as you say. It seems more generally breezy now, rather
than the stop start winds we've been having.


Hi, Anita and Jack,

The wind direction is really critical here for the stop start wave
effect. A SW'ly will not produce it, but a swing to WSW livens things
up!

Best wishes,

--
Ken Cook, Copley (5miles north of Barnard Castle), County Durham.
830ft
http://mysite.wanadoo-members.co.uk/copley
(MO climat. site updated before 10Z and 19Z daily)
kencookATcopleydurham.freeserve.co.uk
(All times GMT)







---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.806 / Virus Database: 548 - Release Date: 05/12/04




Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[WR] 16/3 Pennine lee slope gales Ken Cook uk.sci.weather (UK Weather) 0 March 16th 14 11:44 AM
(WR&OBS) Copley 25/12, lee slope thaw? Ken Cook uk.sci.weather (UK Weather) 1 December 25th 10 10:48 AM
(WR)Copley lee-slope gale Ken Cook uk.sci.weather (UK Weather) 0 November 14th 08 10:37 PM
[WR] Gale Copley (lee slope effect?) Ken Cook uk.sci.weather (UK Weather) 8 December 30th 04 10:50 AM
Strong lee slope winds today Ken Cook uk.sci.weather (UK Weather) 1 September 15th 03 11:20 PM


All times are GMT. The time now is 03:13 PM.

Powered by vBulletin® Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2004-2018 Weather Banter.
The comments are property of their posters.
 

About Us

"It's about Weather"

 

Copyright © 2017