Model Output Discussion - 17th Oct Onwards

[Summer Sun]

Latest from Gibby

 

All models show a sustained spell of unsettled weather for the coming few weeks. In the short term a ridge of High pressure tomorrow will be swept away by Low pressure moving up across the UK from the SW on Friday and then becoming absorbed into a strong to gale West to SW flow across the UK with a wet day Friday blending into an equally wet weekend with showers or longer spells of rain with temperatures somewhat lower than of late. By Monday the models diverge as the potential for a major storm system approaching the UK develops and is handled differently by each of the models.

 

GFS takes this development directly over Southern England with severe gales carried away from the UK to Northern France although a lot ofrain would be likely instead as it passes over. Pressure rises steadily then with sunshine and showers through the middle of the week. Winds then back SW with milder air sweeping back NE over Britain with rain and drizzle over the North and West. This pattern of alternating mild and changeable weather with drier and brighter spells in the South at times continues throughout the rest of the run with at no point anything particularly cold shown.

 

UKMO tonight looks very stormy Sunday night into Monday as it has the storm system crossing Central England with severe gales over Southern England and Wales. Behind that the rain and showers will continue but with winds decreasing steadily towards the middle of the week with temperatures feeling rather cold.

 

GEM shows virtually no development of this storm at all and just sends a normal if powerful enough in itself storm across the far North with strong to gale Westerly winds and showers and longer spells of rain with snow on Scottish hills. Further changeable weather is then expected over the remainder of the run with temperatures close to or a little below average but with slacker Low pressure by the end of the run.

 

NAVGEM takes the less intense storm over Scotland and therefore is less disruptive to infrastructure over Britain while carrying a spell of rain and strong winds for all. Thereafter, it stays windy and relatively unsettled with further rain at times and average temperatures.

 

The GFS Ensembles tonight look like a colder and very squally and wet period is to come before things moderate somewhat in terms of wind and rainfall from the middle of next week. Temperatures then stay broadly closer to average with more occasional rain and with fairly brisk winds still likely.

 

The Jet Stream is blowing very strongly over the Atlantic towards the British Isles currently and doesn't look like weakening or moving trajectory or latitude anytime soon.

 

In Summary the potential for a severe weather event at the end of the weekend remains tonight. Embryonic signs of a depression way out over the Atlantic will get caught up in our Jet flow with the potential for it then to develop explosively as it approaches the weekend at the end of the weekend. the event is by no means certain and may just blend into the general weather picture of wet and windy weather with sunshine and showers in between. As we move through the middle and end of next week and beyond prospects are still very uncertain though it looks more likely that no cold, frosty or foggy weather is likely in the near future.

 

http://www.norton-ra...is(2859336).htm

[ICETAB]

This chart looks rather interesting to me.

 

I'm expecting the ECM to start throwing up a scandi high in the coming days.

[Frosty.]

And the outlook from the CFS 12z for nov/dec/jan/feb & march is...BECOMING COLDER AND COLDER AND COLDER..    ooo I like the look of FEBUARY and MARCH

[Snowman.]

This chart looks rather interesting to me.

 

I'm expecting the ECM to start throwing up a scandi high in the coming days.GEM240.gif

 

 

Much easier to see only problem is it would either topple or be dry.

 

You would need a better NH pattern to get something decent.

 

Edited October 23, 2013 by SN0WM4N

[suffolkboy_]

The only problem now though is flooding seems inevitable in places which is not good news

 

Flooding is a normal thing. People seem to think it's not normal for a river to flood. It is.

 

I would be wary of what the models are showing for early next week. How many times have we seen a monster storm being shown, even up 24/28 hours beforehand, only for the models to back down and we end up with a watered down version. It happens nearly every autumn and 95% of the time, the models over intensify everything. Ofcourse, saying that, it's worth keeping an eye on. Severe gales on coasts certainly seem possible.

[fergieweather]

I wish the ECM had a 132 hour chart. It would make things so much clearer.

?? It does. Low centered 12z Mon approx just S of Hants. PPN tallies troubling across S England irrespective of windfields.

[Frosty.]

It's like October 1987 all over again..bbc weather tonight nervous about an evolving major storm system which may be on a collision course with the uk.....or as mr fish said back then..the strongest winds will be over northern france, history to repeat itself, well no because surely the latest technology will avoid egg on faces this time..?

[chionomaniac]

ECM T+126 wind fields

 

 

[DAVID SNOW]

It's like October 1987 all over again..bbc weather tonight nervous about an evolving major storm system which may be on a collision course with the uk.....or as mr fish said back then..the strongest winds will be over northern france, history to repeat itself, well no because surely the latest technology will avoid egg on faces this time..?

But its still 5 days away, give the forecasters a chance.

[Jason T]

Flooding is a normal thing. People seem to think it's not normal for a river to flood. It is.

 

I would be wary of what the models are showing for early next week. How many times have we seen a monster storm being shown, even up 24/28 hours beforehand, only for the models to back down and we end up with a watered down version. It happens nearly every autumn and 95% of the time, the models over intensify everything. Ofcourse, saying that, it's worth keeping an eye on. Severe gales on coasts certainly seem possible.

 

Yes they do SB, However on the other hand they might not this time. 

[lorenzo]

?? It does. Low centered 12z Mon approx just S of Hants. PPN tallies troubling across S England irrespective of windfields.

The material we can access plots every 24 hours, the point here is about the chart between the jump from 120 - 144 not being available to view from the 12z run, this leaves some blanks to fill in so to speak.

 

One way round this, and granted it is not from the same run is to look at the 00z for the time frame required, as per below.

 

Edited October 23, 2013 by lorenzo

[suffolkboy_]

Yes they do SB, However on the other hand they might not this time. 

 Hence why I said it's worth keeping an eye on   As always....more runs needed.

[TwisterGirl81]

It's like October 1987 all over again..bbc weather tonight nervous about an evolving major storm system which may be on a collision course with the uk.....or as mr fish said back then..the strongest winds will be over northern france, history to repeat itself, well no because surely the latest technology will avoid egg on faces this time..?

I hope France doesn't pinch this low again, of course I don't like to see anyone hurt but we've not had a good storm in the southern uk in years, I like storms when people take head and stay where it's safe....I'm not going to have any nails left come Sunday night!Does anyone know what the sustained wind speeds and gusts could be in the southwest (Devon) worst case scenario....how do people see this panning out? Edited October 23, 2013 by TwisterGirl81

[Zenarcher]

 

 The material we can access plots every 24 hours, the point here is about the chart between the jump from 120 - 144 not being available to view from the 12z run, this leaves some blanks to fill in so to speak.

 

 

One way round this, and granted it is not from the same run is to look at the 00z for the time frame required, as per below.

 

ECM1-120.gifECM1-144.gifECM1-144 (1).gif

Weather Wunderground lets you view the ECM every 3 hours, its not exactly easy to navigate around though http://www.wunderground.com/wundermap/?zoom=4&rad=0&wxsn=0&svr=0&cams=0&sat=0&riv=0&mm=1&mm.mdl=GFS&mm.type=SURPRE&mm.hour=0&mm.opa=100&mm.clk=0&hur=0&fire=0&tor=0&ndfd=0&pix=0&dir=0&ads=0&tfk=0&fodors=0&ski=0&ls=0&rad2=0

 

Here's the pressure chart at 132 hours and comparing it to the 00z run from earlier.

 

 

Wind chart at 126 hours in knots,

 

Edited October 23, 2013 by weathermaster

[Jimmy0127]

It's like October 1987 all over again..bbc weather tonight nervous about an evolving major storm system which may be on a collision course with the uk.....or as mr fish said back then..the strongest winds will be over northern france, history to repeat itself, well no because surely the latest technology will avoid egg on faces this time..?

 

I'm quite impressed at how the GFS spotted this a couple of days ago, given how subtle the instability behind it. 

The ever reliable BBC weather has given me 5 days to batten down the hatches, so I'm going to watch it fade to black to the south of the jet. 

[Tom Jarvis]

looks like the GFS 18z is backtracking to give us a nasty low

Edited October 23, 2013 by Tom Jarvis

[radiohead]

18Z GFS 967-966mb :

 

[TwisterGirl81]

Weather Wunderground lets you view the ECM every 3 hours, its not exactly east to navigate around though http://www.wunderground.com/wundermap/?zoom=4&rad=0&wxsn=0&svr=0&cams=0&sat=0&riv=0&mm=1&mm.mdl=GFS&mm.type=SURPRE&mm.hour=0&mm.opa=100&mm.clk=0&hur=0&fire=0&tor=0&ndfd=0&pix=0&dir=0&ads=0&tfk=0&fodors=0&ski=0&ls=0&rad2=0Here's the pressure chart at 132 hours and comparing it to the 00z run from earlier.ECMs.pngWind chart at 126 hours in knots,ECMWind.png

I'm sorry I'm a novice at charts and prefer MPH but that track looks like it goes along the channel and takes strongest winds on southern flank to France and 45 knots which is like just under 60mph I think....doesn't seem all that violent to me?

[Jimmy0127]

I'm sorry I'm a novice at charts and prefer MPH but that track looks like it goes along the channel and takes strongest winds on southern flank to France and 45 knots which is like just under 60mph I think....doesn't seem all that violent to me?

 

Well below is the latest GFS, and it shows 60mph sustained wind for the far SW. That's quite violent by most people's standards!

 

[Zenarcher]

I'm sorry I'm a novice at charts and prefer MPH but that track looks like it goes along the channel and takes strongest winds on southern flank to France and 45 knots which is like just under 60mph I think....doesn't seem all that violent to me?

 

Yes the ECM isn't that windy tonight its the UKMO that's showing the stormiest charts.

 

The updated GFS 18z has put the winds up here's a gust chart and its in mph.

 

[East_England_Stormchaser91]

Wow, if GFS is anything to go by, the centre of the low passes over N Devon, up the Bristol Channel, across the S Midlands, then right over my house and exiting through The Wash. This really would bring some damaging winds and wild weather if it does come off! Batten down those hatches is all I can say.

[TwisterGirl81]

Well below is the latest GFS, and it shows 60mph sustained wind for the far SW. That's quite violent by most people's standards!

Ok I see what you mean, I didn't know that meant 'sustained'

Thankyou for the information

[East_England_Stormchaser91]

Yes the ECM isn't that windy tonight its the UKMO that's showing the stormiest charts.

 

The updated GFS 18z has put the winds up here's a gust chart and its in mph.

 

gfsgusts.png

Looks like El-Brumo all over again with that vortex feature right over Brum!! 

[Tom Jarvis]

surprised steve murr is not on giving us an insight on what he thinks is going to happen

[TwisterGirl81]

Yes the ECM isn't that windy tonight its the UKMO that's showing the stormiest charts.The updated GFS 18z has put the winds up here's a gust chart and its in mph.gfsgusts.png

That's better! 😉 wow nearly 70mph sustained here, that's not even taking into account the gusts...I think I'll be paying for parking at work on Monday then.....I guess we won't know for sure the probable path til Sunday? I've told a few people to be careful Monday....