Serious Weather next week?

[Will]

There's been a lot of crazy talk today about next week having 100mph winds and snow. From what I've learnt off our local weatherman (Op), you can't predict that far ahead with any real accuracy.

But if you're reading Op, I'd love to hear the lowdown. It would be truely terrible if I was unable to get to work because of snow drifts. :D

[chillitt]

i need to know the answer to this one - there is a set of skis in the charity shop next door for a tenner. should i invest, or not?:confused: :)

[optrex]

Well you guys you know where to come for the serious weather chat, however, on this one occasions I will indulge ;)

Here is a forecast model for the next 9 days
http://img153.imageshack.us/img153/4359/avnpanel178ebcfab1.th.jpg (http://img153.imageshack.us/my.php?image=avnpanel178ebcfab1.jpg)

Now if we were surrounded by high pressure (light winds = less movement) so you could perhaps goto 5 days with moderate accuarcy. However we have low pressure systems (high winds= more movement/speed) therefore less accuracy.

Forecasts for todays situation changed by the hour, due to the speeds and movement caused by a deepening low pressure.

ATM Thursday 18th looks the most interesting in terms of wind. Here is todays forecast for the 18th.

http://img153.imageshack.us/img153/6169/rtavn16817f61aeyw7.th.jpg (http://img153.imageshack.us/my.php?image=rtavn16817f61aeyw7.jpg)

I'll try and remember to post a copy of it every day so you can see how it changes, as the week progresses.

[optrex]

PS where did you get the 100mph & snowdrifts from ? Not the express again is it?

[Will]

My Dad, the source of all unsubstantiated rumors. But I believe he got it off the news, though I couldn't say which one. They always tend to be a little alarmist when it comes to the weather, which I'm sure always ticks the meteorologist fraternity off a little.

Thanks for the update though Op, much appreciated. ;)

[optrex]

24 hours closer to the event and we can already see changes

http://img101.imageshack.us/img101/9206/rtavn144178b29edm4.th.jpg (http://img101.imageshack.us/my.php?image=rtavn144178b29edm4.jpg)

[Shizara]

My Dad, the source of all unsubstantiated rumors...

:p Aren't most Dads? - Especially if they like to nip off to the pub for a pint and a gossip. They input all sorts of information true or heresay and equally bring all sorts of new rumours home. :beerchug:

[chillitt]

my dad told me, when the ice cream van plays its music, it means they have run out of ice cream...:o

[Shizara]

... and that left enough change in his pocket for his pint?

[chillitt]

... and that left enough change in his pocket for his pint?

sis!:eek:

[optrex]

On this chart, we can see that the low sitting over the north of Scotland, is weakening and moving towards the UK from 960mb to 970mb.

Average wind speeds (not gusts) decrease from the original forecast of 70mph to around 30mph and heavy rain affects just the northern part of the UK, with showers/light rain across the midlands and south.

http://img158.imageshack.us/img158/769/rtavn1201587baa2eg0.th.jpg (http://img158.imageshack.us/my.php?image=rtavn1201587baa2eg0.jpg)

The cooler temperatures though are speading further south across the UK.

[Madhatter]

Will we get snow though?

[Shizara]

We might need to employ the Disney snowmaking machine this year.

[optrex]

Nah, no snow on this particular day. There is a thing called the 528 DAM thickness line. This brings the possibility of snow and its nowhere in site on the 18th

[optrex]

Again for the 18th, you can now see the wind has dropped, but colder air flow decends across the UK

http://img442.imageshack.us/img442/2650/rtavn961vf4.th.png (http://img442.imageshack.us/my.php?image=rtavn961vf4.png)

[optrex]

This is fun. Now perhaps you get an idea of why its so so difficult to forecast these things. Another 24 hours goes by and look how things change. Don't forget we are still looking at 12:00 hrs on the 18th Jan.

On this occasion, you can now see that the isobars have compacted across the UK

http://img181.imageshack.us/img181/1590/rtavn7819c78a23ayb6.th.jpg (http://img181.imageshack.us/my.php?image=rtavn7819c78a23ayb6.jpg)

The proximity of the isobars indicates increased wind speeds and actually gives enough cause for alarm, that I am hoing to switch to another more detailed chart, for comparison.

[optrex]

OMG! here you can see the detail. Don't forget we still have 3 days to go, so things will change, rain across the country, but on this run you can clearly see heavy rain is expected over Snowdonia, Cumbria and the Pennines.

http://img181.imageshack.us/img181/79/2007011500h084uk00sfc1ke1.th.gif (http://img181.imageshack.us/my.php?image=2007011500h084uk00sfc1ke1.gif)

Winds are excessive - definately gales across the whole of the country, with gusts around 60-70 mph in exposed areas.

[optrex]

I feel like I'm talking to myself on this thread ;)

Subtle change again today as the low drops deeper. Still wet and windy, France looks as though it will get stronger winds than the UK. Midlands currently getting the worst combination of heavy rain combined with the strong winds.

http://img407.imageshack.us/img407/9228/2007011600h060uk00sfc1xb3.th.gif (http://img407.imageshack.us/my.php?image=2007011600h060uk00sfc1xb3.gif)

[Will]

I am listening, I'm just not going to pretend that I understand some of the names you're coming out with, :D

It is appreciated and I'm definitely gaining some insight into how precarious weather forecasting is. :)

[optrex]

Oops, I thought I was keeping it simple - what names do you need me to clarify?

[chillitt]

i would have replied, but i was out filling sandbags and battening down hatches..;)

[Madhatter]

Like will said.Please carry on, most interesting.

[optrex]

http://img245.imageshack.us/img245/3978/2007011612h048uk00sfc13vr2.th.jpg (http://img245.imageshack.us/my.php?image=2007011612h048uk00sfc13vr2.jpg)

This is the 2nd run of today, but as it shows a significant change to Scotland, I thought it would be worth showing. As you can see, the isobars are less pronounced, indicating light winds for Scotland. The tighter the isobars, the stronger the wind, so the rest of the country remins very windy.
Isobars are the black lines on the chart. Each line represents a 2mb change in pressure.

Low pressure systems rotate in an anticlockwise direction, so as the low is in the North Sea, you can see that winds will be from West to East. (Highs rotate in a clockwise direction).

Rain is indicated in the colours. Dark blue upto 20mm, light blue upto 10mm, dark green upto 5mm in 6 hours.

[Shizara]

Well... it is snowing in Stirling..... Can someone blow a bit this way?

[Shizara]

... also Glasgow and Hamilton

[Madhatter]

big kid aren't ya hun, you'll be out there building a snow man.

[optrex]

big kid aren't ya hun, you'll be out there building a snow man.


You'd have to get past me first ;)

[optrex]

Seeing as you lot are obsessed with snow (aren't we all) I found this.

This chart is the closest I have for now. (reports of snow across northern Scotland tonight) This is the midnight forecast for Tues/Wed 17th Jan.

http://img152.imageshack.us/img152/4029/2007011612h012uk00sfc1hi8.th.gif (http://img152.imageshack.us/my.php?image=2007011612h012uk00sfc1hi8.gif)

See the blue dotted line across the northern edge of Scotland. This is the 528
DAM line (its a thickness of air measurement) but as I mentioned earlier, its what is associated with snow. Basically, if you have that and you have rain, 9 times out of 10 it will fall as snow or a wintry shower.

[Shizara]

big kid aren't ya hun, you'll be out there building a snow man.

Of course! Are you going to help?

[Shizara]

Should it ever snow here again I think we all have an obligation to take photos, make snowmen and take more photos... The gallery is a handy place for them too :yippee:

[optrex]

You might just have your wish sooner than you think. For the UK as a whole, Satuday to Tuesdays has strong possibilies.

Snow on the way for the weekend? - Midlands Weather Forum - A UK Weather Forum (http://www.midlandsweather.org.uk/uk-weather-chat/4681-snow-way-weekend.html)

[Madhatter]

Ok i'll help but no going indoors cos it's too cold and leaving me to finish it.
Snowmen look good if you build it then it snows again so that its white around it/him/her.
It never lasts let alone lasts long enough to get a second fall. :(

[Will]

Should it ever snow here again I think we all have an obligation to take photos, make snowmen and take more photos... The gallery is a handy place for them too :yippee:


Splendid Idea! Also if anyone sees any floods over the next few days, or damage from the winds, get those too!

Look at me telling all what to do. :D

[optrex]

Don't foget a copy for me too please ;)

[optrex]

Here is the latest run for 12:00 on the 18th. The low is forecast to have an enlarged center, than previous forecasts, with pressure down to 966mb

Heavier rain at this time is now centered over cumbria, and Scotland.

http://img296.imageshack.us/img296/8124/2007011712h024uk00sfc1cr0.th.gif (http://img296.imageshack.us/my.php?image=2007011712h024uk00sfc1cr0.gif)

If you need more detailed analysis, you may wish to look at Discussion: Severe Weather 17 to 18 Jan 2007 - Midlands Weather Forum - A UK Weather Forum (http://www.midlandsweather.org.uk/uk-weather-chat/4673-discussion-severe-weather-17-18-jan-2007-a.html) Where we are following the whole day, not just the 12:00 hrs forecast period.

Winds are due to remain strong and from the west. Damage is still likely and weather warnings have been issued and you are advised to keep up to date with flood warnings for your area.

[Madhatter]

I've got an idea. Judging from this you may be interested.

[optrex]

This will be the last chart for the time we are looking at 12:00 on the 18th Jan 2007.

As you can see the pressure has decreased to 964mb, as the low deepens. Also the isobars are closers again, so winds expected to gust 80mph in exposed areas.

Looks like I picked the right day to study.

http://img256.imageshack.us/img256/5614/2007011800h012uk00sfcablw2.th.jpg (http://img256.imageshack.us/my.php?image=2007011800h012uk00sfcablw2.jpg)

[JWR]

the fence in my garden has just blown over as i sit in my office and watch helplessly ! so forum will, i guess your predicitons were right .... its like a hurricane out there !

[optrex]

Its certainly caused some structureal damage around the Birmingham area. Where abouts are you JWR ? If anyone else has damage reports, please do let us know here and at Damage reports 18 Jan 2007 - Midlands Weather Forum - A UK Weather Forum (http://www.midlandsweather.org.uk/uk-weather-chat/4685-damage-reports-18-jan-2007-a.html)