Autumn Storms/Severe Weather Discussion

[Saphira]

Hi guys

Well as you can see i have not been round much IRL does that sometimes. However this Mondays storm event is worth a topic, now as many have gathered yet again the media have over hyped this (but for good reason). Now if this bores you and your not into weather then dont read it

I will explain why now..

Ok so this storm has been monitored by weather enthusiast for about a week now, i myself have done nothing but look at data, graphs, models, GFs, etc..endless tbh. Now the reason for the excellent media coverage is the possible chance of a Sting Jet (will explain more on that later) and also the Low weather front Lorenzo that passed UK will played a big part in how this Storm! can/might/will predictably turn out and how both the northern and southern flanks of this storm will be affected, and its path it takes..Anyway this storm had not even been born yet but with today's technology and data readings us weather bods could see it developing. Now what is unusual is the high temperatures that the UK have been having, this has also played a significant factor with the storm (now named Christian).

Now lets get to the Graphs etc, this is the exciting bit, many wont understand them so i will do my best to explain.



Now on this image you can see the tightly packed isobars as the deepening low passes through the UK, the tighter the isobars the higher the winds, also the potential for severe wind gusts.



On this image you can see the pressure dropping which will increase the wind gusts even more (potential for in excess of 80-90 mph gusts in coastal/exposed areas), now even more concerning is the Sting Jet i already mentioned, this has the potential to develop and if it does we could see wind gust over 90mph, possibility of them reaches 100mph.



Now this is the worrying part that all us weather bods have been banging our heads over, as you can see the pressure bars have dropped to a staggering 966 (hurricane force) as the Low moves NE wards. Now if the sting jet does become existent in this deep depression then things will be stepped a notch or two.



Now this chance signifies the potential for a tornado on the southern flank of this storm, we are not ruling out potential of a tornado to exceed an F3 with its cores reaching 120-150mph. It's shear is impressive.

Jet stream + unseasonably mild weather + wind shear + low pressure system (possible Sting Jet) will all plays major factors in this storm, however the data is still yet coming in and changes are apparent, possible shifting more north, if this happens then the Low will run further over the midlands, and south wont get much of a battering, if the Low stays on course as it is now the south will be somewhat batter, if the Low passes further south then France will get a battering. Expect power lines down, power outages, fallen trees, flying debris, flooding, structural damage to properties etc. On a safe note stock up on candles, and essentials, and more importantly DONT travel unless absolutely necessary (even worse for island as all travel crossings to the island will be suspended) Looks in cupboard, "how many candles do i have", ooops! only one lol...



This is the expected path it will take (if the low does not shift). Now these storm can change course quite rapidly as this time of year our Jet Stream is raging quite fast with speeds off over 200mph.

Right - The Sting Jet

A sting jet is a meteorological phenomenon which is believed to be the cause of the most damaging winds in European windstorms.

The definition of a sting jet -

Originates at mid-levels within the cloud head
Descends along a sloping surface of constant wet-bulb potential temperature
Accelerates and dries during descent
Results in strong winds near the top of the boundary layer
Results in localised strong surface gusts at the surface
Persists for several hours
Distinct from the low-level jets associated with the warm and cold conveyor-belts.

Anyway, the latest models (within past 5 minutes) GFS, NAE etc have put this storm a little further south, so that means it could potential hit out in the English channel and France will take the brunt of it, however this Low has literally only just been born and expect a lot of change in the next 24hrs. Im hoping it will go further south and miss the UK, if it dont im right in its path and also live right on the southern side of the island in quite an exposed area.

[Dan]

Interesting and well composed post. Thanks Saffy!

[[TC] Shino]

Thanks for this Saffy, very interesting!

[[TC]►Bez◄]

(2013-10-26 10:30)ags463 Wrote:  Thanks for this Saffy, very interesting!

ags463(Shino): "I liek the colours the most heheheh"

Very nice post Saff! Enjoyed reading it! looks like you Southerners are going to get hit the worst. My mums on about buying candles as well just in case, but we're in the East Midlands so I doubt we will have it as bad as you.

Stay safe!
-Bez

[Jedi]

Nice read Saffy, hope you guys will be alright. It probably will come towards Bergen afterwards.
I like the name of the storm

[Saphira]

Its exact tracking once leaves the UK is not set in stone yet, it really does depend on how this low develops in the next 24hrs as to its path it will take and the severity it will punch out.. I have data coming out of my ears lmao..Computer says "no" i think its gonna go on meltdown hahaha.

Edit @ 11.52am

NAE modified much towards EC & new GM (broadly similar).(sorry for technical weather talk) So, low centre shifted NW, slowed a tad & deepened (not good for us southerners). However there are rapid changes now taking place with this system, our data readings,ensembles are going nuts and subtle changes are now becoming apparent as this Low gathers strength and pace and starts to develop more. The exact track still looks as if it will pass right through the center of the UK, but like said some models show very very slight changes. Anyway cuz im a weather bod i will also mention another Low system possible to be born and cross UK sometime next weekend (possibly) again exact tracking far far to early as we have only just picked it up

[Jedi]

Well the strong winds and rain we had this week probably came from Uk. The targets blew over and crushed about 15 arrows in the archery club. Was interesting shooting in the rain and wind.

[Tom]

i currenty have a weather station broadcasting live feeds at the llowest point of the uk will be interesting

[Saphira]

Tom what is your data reading, soo many weather stations have fired up on IOW

My god the pressure is dropping fast

[Saphira]

(2013-10-26 11:01)Jedi Wrote:  Well the strong winds and rain we had this week probably came from Uk. The targets blew over and crushed about 15 arrows in the archery club. Was interesting shooting in the rain and wind.

That was Low Lorenzo that caused your strong winds.

Update @ 12.51

Storm Christian has now developed closed circulation in the Atlantic and is now currently racing across Eastwards at over 80mph under the influence of a powerful Atlantic jet-stream. It is now widely expected that Storm Christian will cause some significant damage to the UK over the next 48 hours. There are three main concerns regarding this system.

The first is the amount of rainfall which Christian will dump across Southern parts of the UK. South-west England can expect up to 75mm of rain (3 Inches) whilst Southern England can expect up to 50mm (2 Inches) of rainfall during Sunday evening and overnight into Monday morning. This is likely to cause local flooding in itself, but add on the rapid leaf fall and this only serves to inflame the situation.

The second is the wind. The strongest of the winds are expected to push across Southern England during the early part of Monday and into the afternoon. Sustained winds of 40-50mph inland and 50-70mph along coastal locations are expected. Gust speeds will increase dramatically during the day and push East along Southern areas. Inland gusts of 60-80mph can be expected across Southern and later Eastern areas.

The third is the compounding effect of trees still in leaf, recent heavy rain with saturated ground and the timing of the system.

Is it fair to say..the hardest part to forecast at this stage with any accuracy will be developments as the LP is directly above our shores? In terms of strength etc - Obviously it's track will be vital in all of this too. As mentioned already, the 'sting' in the proverbial tail could well be over more (flatter..) E/NE parts as the likelihood of it entering the North Sea are increasing... It is here where much colder air masses shall be stoking this beast further..


Latest data readings that i just got are below -



Now this is impressive, again data just in..The storm surge! For Monday morning 30 to 32ft to the South West of England and 20 to 25ft in the English Channel.

[Johan.]

May the force, well, actually this time, not be with you! (talking about windforces and such)

And god damnit, we better not get a tail, just washed my car.

[James]

Jesus.


Lets hope people will be ok.

Also, I was out in a small lightning storm yesterday. Freakin' loved it!

[[TC] Shino]

(2013-10-26 10:34)Bez Wrote:  

(2013-10-26 10:30)ags463 Wrote:  Thanks for this Saffy, very interesting!

ags463(Shino): "I liek the colours the most heheheh"

[[TC] Connor]

Wow, can't wait to see what this storm's like! I'm down the south east of England so I'll probably get hit hard won't I? Better stock up on candles!

Maybe I'll draw a picture of what LFS looks like in my car and pretend I'm playing it if it cuts off all the power!

[SO•Yukine]

How it affect Paris?

[Cola]

Looks pretty impressive. Can't wait to see pics and videos. GL to you in the way of the storm.

[[TC]►BP◄]

Quote:"There's also the possibility of flooding with torrential downpours and leaves blocking drains. South Wales and southern England are most at risk."

Terrific.

[Louis [CA]]

Thanks saffy, and that's the weather brought to you by TC City driving news.

Nice news report!! From yesterday's forecast I had the option to have torrential rain up north (home) or high wind down south (grandparents) I chose to watch the great south run tomorrow and then to London on Tuesday (cruising the m6 as we speak).

A little off topic and on my mobile (apologies for typos/ grammar problems)

[Saphira]

Update -

This Low has now intensified the latest GFS/models given below



It has deepened and the original track is now still in situ, however again the next 24hrs will be watched closely as data/tracking etc are still not set in stone as Low Christian is yet to meet up with another Low.


The next image below now shows a much more defined area of the Low, you can see the deep red/black colour, that is Low Christians expected path, and the pressure has dropped low then originally expected. This could turn out to be worst storm in 20 yrs if this stays on track and intensifies, however like said theses storms are unpredictable.....

---

(2013-10-26 16:07)Bruno_G Wrote:  How it affect Paris?

If this storm stays on track then Paris wont get much, if it tracks further south (out in english channel) then its possible France will bare the brunt of it, how much of france i dont no as GFS models are still not 100%

[Saphira]

New NMM6 is just out and the English Channel winds look ferocious, Sunday night right through Monday morning. For you guys who live southern england please please take extra care/precaution, storms like this are not to be blinked at. Get your essentials ready..Torches/candles etcetc, its now looking more and more likely that power lines will come down, electricity will go off and major disruption likely.

There are going to be warning updates on all major weather sites shortly