Ex Ts Katia To Hit The Uk - Chat Thread 2

[cookie27]

can anyone point out the centre of the system we are watching . things do see#m to be moving N / NE on the latest sat pics .

getting a bit windy here down south would guess 30mph then quiet and a then its just gone quiet, like being in the tropics

[ZONE 51]

http://www.zamg.ac.at/wetter/sat_bilder/?ts=1315796882 - good site if you can understand what it all means!

[PeterDoswell]

centre becoming much clearer on the 0400 sat if i am looking at the right area lol all seems on track to affect scotland and northern ireland now . moving northeast at approx 35mph

[ZONE 51]

The Sting Jet

In recent years, this phenomenon has come under scrutiny, and is now accepted as a process responsible for the strongest surface winds experienced. As the very dry air descends rapidly from upper levels in the developing storm, it doesn’t just bring the air down with it. Simplistically, it also drags the frontal jet down with it too. In effect, part of the jet-stream is actually deflected down to the surface – no wonder it’s windy !

When looking at the satellite imagery, imagine where the first part of the baroclinic leaf starts to wrap around itself. This can resemble a hook shape, or as is often said, it looks like a scorpion’s tail that is being wrapped up. On the forward-nose of this hook, as it turns back eastwards, is the area where sting-jets can occur. As the dry upper-air descends through the cloud head, it cools evaporatively, and becomes more dense than its surroundings. As a result, it descends quicker and quicker until it smashes down to the surface. As this hits the surface, exceptionally strong gusts of wind are reported. Remember, these are gusts of wind which are already occurring on top of the already very strong winds. For instance, in North Wales in the Christmas storm of 1997, sting jets created gusts in excess of 100mph, creating much damage.

It’s worth remembering too, that in many deep depressions we see in the UK, the strongest winds are usually (but not always) on the southern flank of the low. Sting-jets just make these winds even stronger!

[PeterDoswell]

electricsnowstorm . i think you were right about the rapid intensification . compare the 0300 sat to 0400 sat

[ZONE 51]

-

its moving EAST! just done some re-runs..

[PeterDoswell]

east ? i got north east at about 35mph on my calculations

[stoke weather watch]

Wind getting up now here in Macclesfield and just had a Gust strong enough to blow my Bin over that is out for the dustbin men later.

Edited September 12, 2011 by stoke weather watch

[ZONE 51]

look at this - 2am/3am ive lined up lines from top to low center and lined to east and you can see it has moved east and not ne..

(large file size)

[Cymro]

Incredibly windy here in the Brecon Beacons South West Wales. As I previously said the winds in Wales especially southern Wales have been hugely underestimated. The higgest gust ist currently 63mph (sustained wind speed of 45) now this is the highest in the UK as it currently stands, and Wales has constantly for a long period now shown the strongest winds on the observatory.

Perhaps things will change come mid morning and t hings will change here in that respect but as it currently stands its in Wales that the greatest winds are being recorded.

[ZONE 51]

ah yep slightly northeast movement your right PD!

just had a closer check and run more sat images

[kmanmx]

Ah, so back on the predicted track then ?

Hows the intensity, as predicted ? or stronger/weaker ?

Things seem windier here than they were 2 and half hours ago, but according to my local weather station the 23mph gust at 2:06am still has yet to beaten. Seems wrong to me but it's probably not.

Edited September 12, 2011 by kmanmx

[ZONE 51]

Dover

Gale warnings - Issued: 2141 UTC Sun 11 Sep

Southwesterly gale force 8 imminent increasing severe gale force 9 soon

Shipping Forecast - Issued: 2315 UTC Sun 11 Sep

Wind Southwest 7 to severe gale 9, occasionally 6 at first. Sea State Moderate or rough, occasionally very rough. Weather Rain then fair. Visibility Moderate or good. http://www.metoffice.gov.uk/weather/marine/shipping_forecast.html#All~Dover - warning for all seas and coasts of GALES or STORMS

[GreatStorm1987]

Has anyone else read the Met Offices updated forecast for today? North West England & North Wales are the only Regions which it says there will be Storm Force Winds, this Storm is obviously tracking much further south than previously thought!!!

[Alan Robinson]

What I missed in this thread was Alvar Lidell reading the shipping forecast. The best I could find was this....

[ZONE 51]

GFS - 00z - LATEST RUN IS AN UPGRADE TO MORE WIDESPREAD DAMAGING WINDS ACROSS NORTH

ALL ORANGE IS GALE....SEVERE GALE IS DARKER ORANGE-REDS STORM FORCE

THIS IS ONLY GFS ALONE BUT INDICATES A STORMY DAY FOR MANY.

THE SOUTH IN EXPOSED PLACES COULD SEE SEVERE GUSTS MORE THEN 50MPH

gust chart is for 1200hrs and stronger winds may occur before and after this time and also this chart is only really a guide to what could occur and gusts may be higher.

Edited September 12, 2011 by ElectricSnowStorm

[ZONE 51]

great site - http://www.marinewaypoints.com/marine/wind.shtml - all you need to know about wind scale

[GreatStorm1987]

This is starting to look potentially very dangerous for Northern parts of the UK below the Central belt of Scotland.

[ZONE 51]

It is a dangerous big storm thats going to be prolonged lasting many hours once the winds set in , this was hurricane Katia so tropical elements causing some torrential rain for the North, the South is going to be warm so its almost like a tropical gale down south with temperatures predicted to be as high as 21c!

NORTH-65-90mph damaging winds and gusts

SOUTH-40-55mph possible damage in strongest exposed gusts

trees are of course in full leaf for most so very much a concern even 50mph can pull down a full leafed tree.

this event is to affect all regions.

Edited September 12, 2011 by ElectricSnowStorm

[GraemeB]

Stirling to Glasgow M80 - very VERY wet, lots of surface water and the rain is chucking it down - interestingly - not much in the way of wind. I suspect when the low starts moving ne(ene ?) that there will be carnage in central scotland ... especially as it looks to hit mid afternoon/rush hour.

[smoggyjester]

it is very windy here in waterlooville in hampshire, quite wet too

when is Katia due to actually hit?

[ZONE 51]

here in Surrey its already blowing a constant gusty wind and its very mild, all trees are swaying and thats here! imagine how its going to get in the high risk areas if trees are doing this here now before its even peak winds!

it is very windy here in waterlooville in hampshire, quite wet too

when is Katia due to actually hit?

X-Katia.. she is rolling in now this is the start of it and it feels like a hurricane setting in but it is now a storm

Edited September 12, 2011 by ElectricSnowStorm

[smoggyjester]

ok cheers, know what u mean lol, anyways gotta go to work in a min wind is getting stronger here

[The PIT]

Well so far here ave 17 mph max gust 39 mph which is what GFS predicted for this time. Should in theory be upwards from now on.

[Snowmad79]

great site - http://www.marineway...rine/wind.shtml - all you need to know about wind scale

Cheers for that link. According to that Im somewhere between Strong Breeze to Near gale. Doesn't seem windy at all to walk in and small trees are barely moving but the tall trees are definitely on the sway...

Heres the sat image for 06:00am and roughly where the core was at that time:

Edited September 12, 2011 by Snowmad79