Atlantic Storms - Autumn 2012

[aggy]

whos nadia?? maybe nadines got a twin sister thats going to make an appearance to.

MISSSPELLING LOL

[Liam J]

NAE coming into range now, and @ 48 hours the frame looks very different to the other 12z model runs - It's not wanting to develop any energy spawned off Nadine. Kind of out on it's own with this evolution for the time being (bar the nogaps & JMA) i'd be more inclined to place my confidence with the ECM/GFS although another outcome could be the UKMO...... Hmmm certainly not going to be easy to call for another 24hrs or so I dare say!

http://www.weatheron...E=-&WMO=&ZOOM=0

ECM 12z would bring the windiest outcome

Scotland getting hammered on this run

Edited September 20, 2012 by Liam J

[ZONE 51]

Certainly an interesting development, feeling a bit concerned seeing whats possible and especially as trees are in leaf, and with the large rainfall possible we could see flooding, this is a rather complex situation, and with the models getting a handle on things as we get nearer the weekend then we should know where the worst of this potential storm would hit, the movements of Tropical storm Nadine are vital to the developments of the new system-and it's this that could be fuelled into a storm and head up from the south to our shores this weekend, with all the energy available down there i would not say its not possible for a strong wind event, a lot of moisture will be in the new weather system when it develops and this leads to lots of rainfall. I expect this new system to develop, but the question is the track.

Then after that what happens with Tropical storm Nadine..

Edited September 21, 2012 by ElectricSnowStorm

[AWD]

GFS 0z brings some strong winds around coastal areas, especially around Scotland and down into the Irish Sea.

Edited September 21, 2012 by AWD

[Liam J]

Well back the original plan with the GFS 00z run, heavy rain spreading up from the south accompanied by very strong winds over most areas - widespread gales developing. Worth noting the UKMO model is still having none of it and keeps the depression much further east, not set in stone by any means.

GFS dartboard low

Very wet & windy into the south, E-SE gales as the depression tracks north, winds then swinging W-SW

976mb low centre with strong winds/gales around the perimeters

Edited September 21, 2012 by Liam J

[AWD]

If the UKMO verified, then whilst the winds wouldn't be as strong, there would still be plenty of heavy rain around for the south in particular.

http://t.co/LYk5vtyT

ECM has the heaviest rain a bit further NE.

https://pbs.twimg.com/media/A3S-nERCIAASsIH.png

Edited September 21, 2012 by AWD

[Snow and storms]

This low could prove to be very interesting, we have some models saying its going to be a severe weather event, some dismissing it and a whole bunch sitting in the middle.

My views are that the low will break away from Nadine and rapidly bomb because of the contrast between the warm sea/air over bay of biscay and the cold laying over the northern half of the UK. The only question will be how strong the jet is

at the time the low builds.

There is also a lot of power tied up within Nadine. From looking at history, the Bay of Biscay is notorious for producing the fiercest Lows that hit the UK with the most unpredictability. I cannot see this being a tame low system but we will have to wait and see.

[Coast]

This low could prove to be very interesting

There is also a lot of power tied up within Nadine.

Check this post I did linking Laim Dutton's blog, which shows how difficult this weekend is to forecast:

[johnholmes]

I have no idea why but predicting the track and intensity of lows approaching from the south has always been more difficult than those between SW and NW.

[gottolovethisweather]

The thing most folk down south will remember from the "don't worry there isn't a hurricane" scenario back in 1987 was the winds of course. However, another feature during that evening into the overnight period was the notable feel you got, of the mixing airmasses. The rain was thundery in nature too. This time around, there is not so much talk about this aspect.

My question is therefore, how much difference is there between the anticipated airmasses over say Northern France, when compared to Northern England for example.

[Verglas]

there seems to be a bit of a difference between the metoffice and wetterzentrale in where the low tracks up the channel, metoffice seems to show it more concentrated heading up the north sea ?

[Storm Track]

There are risk of severe thunderstorms likely, bringing heavy band of rain with some very strong winds gusting up to 50-70mph in the Southern England areas early Sunday and into Monday night with a child of tropical storm nadine will be 50mm plus over.

Just maybe violent storms with strong gusty winds this Sunday or Monday.

[Coast]

I think any thunderstorms will pass to the Southern side of the low in France this weekend, as demonstrated on GFS:

They may just clip the SW coast on Tuesday:

and possibly tickle the SE first thing:

Tracking up The Channel during the day:

[Liam J]

Changes again from the GFS, 6Z run has the depression further sout-east on it's approach with much less intense circulation as it hits our shores (still very wet). Not the dartboard type low from the 00z run but the end result is similar to previous runs as the low swings back westwards with a very tight gradient on it's NW flank - Gales over the Far north and Western Isles.

Until we have some sort of firm cross model agreement on the depressions track from Biscay towards us then the rest is speculation, Less than 48hours away and we are still none the wiser.... The potential is there for some severe weather, will the ingredients combine and take aim at the UK, thats the question.

As john has mentioned in a few posts this morning, this is a notoriously difficult situation to predict as models for some reason struggle with depressions attacking the UK from the south. A bit of a nightmare to try and give advanced warning to the public and I have no doubt the situation is causing a few headaches for weather forecasters at this very moment.

Edited September 21, 2012 by Liam J

[knocker]

Surface analysis.

[Coast]

OK, I seem to posting all over the place today, but this is worth thinking about in the mix:

Tropical storm Nadine strengthens as she moves away from the Azores. Currently winds are at 65mph, pressure is 981mb, and she is moving SE at 8mph. While the wind speeds have came up and the pressure has dropped her satellite appearance is dwindling. There is little convection on the NE half of the storm and overall convection is not extremely deep. The reason for strengthening is Nadine is probably getting some non-tropical energy as conditions are not good for strengthening. With the intensity uptick there is some changes in the forecast from earlier.

Nadine continues to be a confusing storm with this intensity jump. This was a surprise given Nadine should be weakening or at least maintaining strength earlier. Also satellite shows that Nadine is not doing good. The whole northern side of the storm is void of convection and there doesn't look to be improvement. In fact, satellite imagery is showing Nadine may be trying to turn extra-tropical which is something to watch. Wind shear is pretty strong over Nadine and SST's are cool so any rising of the winds isn't from tropical organization. I do believe in the next few days Nadine should transition to an extra-tropical storm. Shear could decrease for a little bit but I'm not totally sure if that will happen or what Nadine would even do. After that Nadine's future is up in the air.

Models are still split on where Nadine will go. They can not agree on where/when a recurve would happen. This has been the norm for the models over the past few days. In the short term models show an ESE movement, which is backed up by the current environment. There is little agreement between the global models after a few days. My forecast doesn't have a lot of confidence since models don't have a lot of agreement. I see Nadine moving ESE to SE over the next couple days and then everything is mostly unknown.

http://www.wundergro...tml?entrynum=34

[gottolovethisweather]

I may be reading things wrong but if you were to run a Sat24 animation, Nadine or possibly it's offspring appears to be moving NNE'wards already. Ok, so the "Azorian Beauty" is quite a long way from our shores just yet but I would argue that she is ahead of schedule with her development.

As I originally stated, I may be wrong so somebody please correct me if that is the case.

Edited September 21, 2012 by gottolovethisweather

[knocker]

Sunday forecast

[knocker]

I hope this is wrong as friend of mine is going on holiday to the Lake District on Sunday.

[Zenarcher]

Update using the 12z GFS,

Things start getting windy across Scotland but mainly Eastern areas during Monday night. Wind speeds ranging from 30 to 40mph and some very heavy rainfall for South Eastern Scotland.

During Tuesday morning, the wind increases even more across Scotland where average wind speeds could reach around 45mph. The heavy rain moves up over North Eastern Scotland and we also see some heavy rain appear around Northern Ireland and South Western Scotland.

During Tuesday afternoon the wind speeds gradually ease and so does the rain. Still expect some changes because this is still another 90+ hours away.

[Iceaxecrampon]

I hope this is wrong as friend of mine is going on holiday to the Lake District on Sunday.

A lovely choice indeed.

Tell him/her to take a kite......

[gottolovethisweather]

I just thought I'd reproduce this from the SE regional thread as it comes from a MetO standpoint.

http://forum.netweather.tv/topic/74440-south-east-east-anglia-regional-discussion-september-15th-2012/page__st__260#entry2369829

[gottolovethisweather]

Again I will post another post from elsewhere, very much worth paying attention to.

http://forum.netweather.tv/topic/74255-model-output-discussion-26082012/page__st__620#entry2369908

[ZONE 51]

This low could prove to be very interesting, we have some models saying its going to be a severe weather event, some dismissing it and a whole bunch sitting in the middle.

My views are that the low will break away from Nadine and rapidly bomb because of the contrast between the warm sea/air over bay of biscay and the cold laying over the northern half of the UK. The only question will be how strong the jet is

at the time the low builds.

There is also a lot of power tied up within Nadine. From looking at history, the Bay of Biscay is notorious for producing the fiercest Lows that hit the UK with the most unpredictability. I cannot see this being a tame low system but we will have to wait and see.

My worry is that the models are not coming up with a solution yet. And a concern for what could turn up.

I have no idea why but predicting the track and intensity of lows approaching from the south has always been more difficult than those between SW and NW.

I'm interested in this, could it be to do with the sea surface temperatures in that zone? Edited September 21, 2012 by ElectricSnowStorm

[AWD]

Strong signal for something tornadic perhaps over the next 72 hours?