Cumbria Weather Forum
 Weather chat and discussion for Cumbria - Established 2nd November 2009

 

 

 
  Index  • Wiki  • FAQ  •  Search  

It is currently Tue Jul 17, 2018 8:24 pm




Post new topic Reply to topic  [ 4 posts ] 
 Weather Warning Discrepancies 
Author Message
 Post subject: Weather Warning Discrepancies
PostPosted: Wed Feb 22, 2017 10:13 am 
Professor
User avatar

Joined: Mon Nov 02, 2009 8:52 pm
Posts: 8208
Location: Brampton
Altitude: 117m
Weather Station: Davis VP2
Reply with quote
Last evening I sent an email stating the inconsistencies between weather warnings and local forecasts, this stems from the fact I am in a weather warning for Thursday for snow yet local forecast says 6c and raining. Along with a wind warning, Max Gust 37mph- but last evening reached 45mph with no warning.

This is their reply, I am guessing the first bit is written, the rest copy and pasted from elsewhere.

Dear Paul,

Thank you for your email regarding our National Severe Weather Warning Service.

Firstly, in reference to your comments regarding the snow warning that has been issued, we can confirm ,as you have mentioned, that the warning detail specifies that the impacts will be limited to certian heights and locations across the warning area. In any particular weather event, not every location in the warning area may experience the impacts indicated. However, as you can imagine, if a warning was issued separatly for every single individual area it would become quite confusing and the image and information displayed to the public would not be as effective. Therefore in order to avoid this confusion and ensure that we are informing the public of severe weather in as clearer way as possible, a warning can sometimes span areas which may not see as severe weather conditions as nearby locations.

Secondly in reference to the wind warning, I can confirm that we are constantly monitoring the situation in regards to the current and forecasted conditions across the UK. We can confirm that the winds that were and are being experienced at this current time have not warranted the issue of a severe weather warning. The reason for this is due to the fact that our NSWWS (National Severe Weather Warning Service) assess the weather on a combination of impact and likelihood, you can read more about the necessary requirements at the following links:

http://www.metoffice.gov.uk/guide/weather/warnings
http://www.metoffice.gov.uk/guide/weath ... her-advice

There are various factors involded when deciding the impacts of certain weather conditions, these can include but are not limited to; the time of day; whether it is a holiday period or not; what types of conditions have been experienced prior to the event; what season we are in which for example could influence whether trees are in full leaf or not. A couple of good examples of when impacts can be affected by previous conditions could include modest amounts of rain causing flooding during a prolonged wet spell, or relatively modest gusts of wind producing some structural damage where structures have been weakened by an earlier storm. This are all elements which have to be taken into account when issuing a Severe Weather Warning.

However, our previous NSWWS was criteria based - for example the Met Office would issue a warning when we thought that a particular weather parameter would reach a certain level. This could be something like rainfall of 15mm in a 3 hour period or wind speeds to reach 70+mph and so on.

The revised service as mentioned above is based on "impacts" that the weather is likely to have, rather than on whether a particular parameter will reach a certain level. For example, we could be forecasting 20mm of rain to fall in 3 hours (which is above the criteria of our previous service) but if we don’t think that this rainfall will have an impact on the general public or the emergency responders' community, then we would not specifically issue a warning.

In order to aid our decision making, our Chief Forecasters will liaise with our Public Weather Service Advisors, who are regularly in touch with emergency responders and other authorities in the regional areas, to get an idea about what weather will likely have an impact and what will not.

As always there can be exceptions to a rule so with the issue of a wind warning the decision is still based loosely on criteria; whether the wind will approach 70mph or not is the general trigger. However, we can use our discretion and "flex" this. For example, North West Scotland in winter won’t see any serious impacts from 70mph winds, so we can take a decision to only warn if the winds in that part of the UK are higher, say to 80mph. On the other hand, winds of 60mph across south east England in July, when trees are in full leaf, could have disastrous consequences. If such an event was expected, we could legitimately issue a warning for the lower wind velocity because of the likelihood of serious impact.

We are also concerned with the impacts over a large area so whilst at times there can be local damage (felt blown from a roof, branches torn from trees. fencing loosened etc) our NSWWS is now more concerned with the impact across wider areas.

If you have any further questions or need any additional information, please let us know. Our Weather Desk team are available to assist you 24 hours a day, seven days a week. Simply reply to this email or give us a call on 0370 900 0100 and one of our advisors will be happy to help.

Kind regards,

Kieran
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

_________________
Paul C
Brampton. 117m ASL.
http://www.bramptonweather.co.uk
Imagehttps://twitter.com/#!/pacrabtree


Offline
 Profile  
 
 Post subject: Re: Weather Warning Discrepancies
PostPosted: Thu Feb 23, 2017 10:02 am 
Area Forecaster
User avatar

Joined: Mon Jun 07, 2010 10:20 pm
Posts: 2281
Location: Bolton le Sands
Altitude: 10
Weather Station: Labjack
Reply with quote
I guess that emant like it or lump it we are always correct.

Mike

_________________
Bolton le Sands

www.lancastrian-imaging.co.uk/sp/weather/


Offline
 Profile  
 
 Post subject: Re: Weather Warning Discrepancies
PostPosted: Fri Feb 24, 2017 1:47 am 
Weather Nut
User avatar

Joined: Mon Nov 02, 2009 10:23 pm
Posts: 1913
Location: Maulds Meaburn, Cumbria
Altitude: 183
Weather Station: Davis VPro2
Reply with quote
I'm sure that the Met'O observers had the following e-mail at lunch-time today:

Dear Observer
As many of you will be aware the Met Office has an Amber Warning in force for snow and strong winds in many parts of the country.
http://www.metoffice.gov.uk/public/weat ... 1487808000

We would be grateful therefore if you could report any weather impacts in your area via the Weather Impacts section in WOW. Weather impacts can be submitted at any time using the ‘Enter Weather Impact ‘ link in the WOW menu bar and are in addition to your routine observation. We are also especially grateful for any snow depth data you can supply during this weather event.

This type of information is very useful for assessing the accuracy of our forecasts & weather warnings.

my reply tonight was:

Mike – I can only speak for my small part of the world, Cumbria, but this was a non-event and there will be no weather impacts entered.
A bit of rain and a max gust of 46 mph is just a fairly average winter’s day – yes I know that there were impacts elsewhere and yes I know that a SWW is only saying that the weather event subject to the SSW may occur in some and not necessarily all of the geographic area to which it applies – but from other observers and weather watchers, certainly here in Cumbria, I'm sensing a great deal of dissatisfaction with SWW’s.
You may want to have a read of some of the comments that others have put on the Cumbria Weather Forum – but for example a warning for:
• 2cms of snow
• rain that fails to hit 10 mm in total
• ice when the temp’ is only getting down to 0.0c
• and then today I rec’d a warning for ice and the temp is only forecast to go down to +2.0c!!

surely these are examples of forecasts and not warnings, but not sure about the last one?

Then of course there are the occasions when the weather was bad and there was no warning!
One of my favourites was back in May 2012 when both the 9th and the 10th had over an inch of rain and there was no warning – I enquired as to why and was told by your enq’ desk:

So, although the amounts of rain you recorded would meet the threshold for a warning, the Chief Forecaster took the view that an area like Cumbria can take this amount of rain as it used to it,

An answer that I thought was both disgraceful and unprofessional – imagine if I made that viewpoint public knowledge, which whilst pre Desmond, was still post Nov’ 2009.

Now I think people in our part of the world only take notice of the very top end SSW’s.

Then of course I am also gauging a high level of dissatisfaction with WOW – so your e-mail following the recent blip in the system at the weekend (why do ‘upgrades’ to systems get done on a Friday – fail – and those responsible go home for the weekend?) was unfortunate in its timing.
Simply – the old system was better.
I guess that will be better for us, but not possibly the Met’O?
You could enter an impact from the same page as your daily obs – not have to go to a separate page and whilst my own dissatisfaction with wow is manageable, for some others it isn’t and you may only be one more system failure from some taking that dissatisfaction further.

_________________
Darren Rogers - he who submits the most interesting posts, AKA Mr Data
Maulds Meaburn


Offline
 Profile  
 
 Post subject: Re: Weather Warning Discrepancies
PostPosted: Fri Feb 24, 2017 10:17 am 
Professor
User avatar

Joined: Mon Nov 02, 2009 8:52 pm
Posts: 8208
Location: Brampton
Altitude: 117m
Weather Station: Davis VP2
Reply with quote
The weather warnings need a overhaul

Yesterdays weather was poor in several areas

1. NW England towards East Anglia - a narrow strip of a warning could have been issued for wind in those areas

2. Snow - Central Belt of Scotland

Apart from that no warnings required anywhere in Cumbria, rain was minimal, only recorded 1mm. Not even Alston got any snow that would cause them concern. The warning page was awash with warnings overlapping each other, I coulndt make where the lines where for what warning

_________________
Paul C
Brampton. 117m ASL.
http://www.bramptonweather.co.uk
Imagehttps://twitter.com/#!/pacrabtree


Offline
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 


 Who is online 

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

 
Index  |  FAQ  |  Search

phpBB skin developed by: John Olson
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group