Tuesday/Wednesday's Event

[Mammatus]

Interesting 10 minutes or so whilst the 18z roll outs.

This is the area im concentrating on regarding winds, especially for those along the south coast and Kent and Essex later on Wednesday/early thursday.

Im looking no further than Tuesday night atm. Disagreement on it's final positioning late wednesday. Tomorrow should start to give us more accurate prgged forecast plots.

Mammatus

Edited August 11, 2007 by Mammatus

[Cookie]

im very much looking forward to this. we could get a battering,

Currently predicted to be around 50-70mph around southern and western coasts, these windspeeds are unheard of in the UK in August, except in 1956/7?

53.3mph was record at this weather station last weekend, so Im sure that stronger winds then that must have been recorded since that date.

http://www.gm7pbb.co.uk/ weather station

[stormchaser1]

Update for Tuesday`s Low

Nigel

[kold weather]

I still don't think the winds will be quite as high as is being hyped however I think there may be a risk of gales for a time in the south as the system swings what looks to be a wave towards the SE, possibly gusts between 45-55mph based on the GFS run.

Also it does have some decent foward speed and if there was somewhere to watch it would be in the south and the SW/SE which will be to the south of the center where you'll get the higher winds due to the addition of the foward speed to the winds already being generated by the pressure gradient. If I had to place the best chance of winds above 60mph it would be down there.

If it come soff like predicted its going to make for a horrid August day. Rainy and windy with temps quite surpressed!

Edited August 12, 2007 by kold weather

[PB22]

Tuesday's low has been delayed somewhat by the overnight runs, with many eastern areas likely to see a half decent day for much of Tuesday now before the rain moves in during the second part of the day. Winds don't look like being too much of a feature. Despite saying that, it will be breezy, but the strongest winds could well affect the Bay of Biscay.

[Stratos Ferric]

I still don't think the winds will be quite as high as is being hyped however I think there may be a risk of gales for a time in the south as the system swings what looks to be a wave towards the SE, possibly gusts between 45-55mph based on the GFS run.

Also it does have some decent foward speed and if there was somewhere to watch it would be in the south and the SW/SE which will be to the south of the center where you'll get the higher winds due to the addition of the foward speed to the winds already being generated by the pressure gradient. If I had to place the best chance of winds above 60mph it would be down there.

If it come soff like predicted its going to make for a horrid August day. Rainy and windy with temps quite surpressed!

Whether or not, with trees still in full leaf the load stress will be far in excess of that experienced from similar systems occurring in their more typical winter half window. For 40mph in July read, say, 70mph in Winter. If winds are up at gale force expect a lot of trees down, perhaps exacerbated where soils remain wet to substantial depth.

[biffvernon]

14th August 1979. Looks like it's going to be exactly 28 years to the day since the Fasnet Race met stormy waters.

http://news.bbc.co.uk/onthisday/hi/dates/s...000/3886877.stm

[memories of 63]

I'm flying in to Manchester from the States on Wednesday morning (7.40 am) what's the chance of disruption?

[Rustynailer]

This event may not have quite as high winds now but it looks quite wet. Tonight and tomorrows model runs are going to be hot topics IMO.

I hope its a downgrade from now on as the previously flooded people are going to be thoroughly sick of this type of thing as if they are not already.

Russ

Edited August 12, 2007 by Rustynailer

[johnholmes]

I'll drop my ideas in as I get them, so here with the first comment

Another interesting looking depression being predicted for Tuesday, so let us see how the various models have it at the moment. It will have to be GFS and Met as ECMWF only starts at T+72.

First the Met O Fax for 12z Tuesday (T+60) as available at 1600 BST Sunday 12/08/07

This shows a 'double' structure to its centre by then. The forward one around 52+N 8.5W centre <988mb and the rear one at 51N 13W <992mb

Looking at the equivalent Extra chart for the same time and it too suggests almost a double centre with its main value <992mb off south west Ireland.

We do not have a quantitative rainfall set of charts yet for Extra but taking the GFS ones from 06z Tuesday to 06Z Wednesday they suggest two pulses(as does Extra) of heavier rainfall, both across Wales and the Pennines along with Cumbria. The total by 06Z Wednesday suggests those areas, or some places therein, seeing 25-45mm.

As to wind strengths then no model is predicting, now, any real wind threat beyond gusts to gale force on its southern side as it tracks across the country.

That track, as of the 06z version, 12z not yet to hand as I type, suggests over the Irish Sea and into the N Sea to be off eastern Scotland by Wednesday.

So those are the basics as of now.

Watch for where the low is at 12Z Monday, Met O Fax suggests on its T+36 that it will be at 50N 36W centre <988mb

By 00z Monday at 50N 27.5W <992mb.

It gave its position at 12z today(Sunday) as 44.5N 47W centre 996mb.

The infra red satellite picture is shown below

I'll update each 00z and 12z run from this afternoon until the actual track and rainfall can be clearly seen during Tuesday.

Charts being added as I get time.

Edited August 12, 2007 by johnholmes

[Cookie]

disspointed about the winds

[johnholmes]

if you compare the 'new' T+24 for 12z Monday with its predecessor for the same time with a T+36 label they are pretty similar, with just the forward centre missing on the earlier chart, so met seem unlikely to alter by very much, if at all, their guidance forecasts for the general public or the shipping side.

check here

http://www.netweather.tv/index.cgi?action=...s;type=fax;sess=

Edited August 12, 2007 by johnholmes

[AtlanticFlamethrower]

Unless you're planning to take a ferry to the continent this will be a non-event.

It may get noticably blustery for a day or so, particularly on the south and south east coast, but no more windy than it has been at times this summer.

When it is not raining it would be a great time to fly a kite.

[Geordiesnow]

I think people are underestimating the winds slightly. Trees are in full leaf and especially in high rainfall they can fall down much easier so we can't rule out the potential damage, Winds i will say may range from 40MPH-60MPH perhaps 70 in more exposed and coastal locations.

[tornadomanuk]

I think people are underestimating the winds slightly. Trees are in full leaf and especially in high rainfall they can fall down much easier so we can't rule out the potential damage, Winds i will say may range from 40MPH-60MPH perhaps 70 in more exposed and coastal locations.

Yes I have to agree with you on this one.....plus could there be a chance just behind the rain band of possibly very nasty squall lines with imbedded TS??

Edited August 12, 2007 by tornadomanuk

[Bobby]

I think people are underestimating the winds slightly. Trees are in full leaf and especially in high rainfall they can fall down much easier so we can't rule out the potential damage, Winds i will say may range from 40MPH-60MPH perhaps 70 in more exposed and coastal locations.

Trees are usually in full leaf in September and October also where we get lots of gales. Doesn't seem to be much of an event to me either this.

[laserguy]

My gut feeling is that this thing will cause a little inconvenience but otherwise come and go without incident. Y'know,like we have 2 centimetres of snow preceded by the most dire warnings.

[shuggee]

I don't understnad what all the fuss is about at all. Oh, it's going to be a wee bit windy and raining. Come to Edinburgh - it's been like that for three of the last seven days

[SizzlingHeat]

what is all the fuss about strong winds, this looks like nothing to me, winds around 30mph gusts max, the heavy rain is the worry not the wind. no idea where some people are getting 70mph gusts from this sort of chart :S

woooo, windy!!! (in a sarcastic voice!)

[johnholmes]

all 3 of the major models have a similar but not the same charts for the period in question.

The rainfall is the one to watch at the moment but the wind may become a feature nearer the time. At the moment apart from my comment in my earlier post not so.

There are points to watch, again outlined above, as to how near the Met O Fax predictions turn out to be.

The first check is for Monday 12z, the low should be around 50N 36W below 988mb.

Edited August 12, 2007 by johnholmes

[Weather-history]

Rainfall looks a worry

Thats a poor chart for August

http://www.wetterzentrale.de/pics/brack1.gif

Then a secondary low has a crack at us

http://weather.noaa.gov/pub/fax/PPVJ89.TIF

http://weather.noaa.gov/pub/fax/PPVK89.TIF

[PB22]

Recent model runs have increasingly played down the strength of the wind, and as most people are commenting, rainfall will be the main concern. Nonetheless, if it hadn't been such a wet summer, we would be looking at just a "normal" wet and breezy spell of weather with no major worries, even though synoptic charts such as those FAX charts for this week are unusual for mid August.

[johnholmes]

at the moment the Met O text forecasts are very closely aligned to their model ouputs and the Fax charts also. These are the ones to watch closely as they are the Chief forecasters view of how he interprets the models, their own and others, principally ECMWF, but not exclusively.

[saint]

i think people may be under estimating the winds but we cant tell till the event or after the event so stop saying there going to be high winds and stop under estimating we cant tell till the event or after :lol:

saint :o

[TEITS]

what is all the fuss about strong winds, this looks like nothing to me, winds around 30mph gusts max, the heavy rain is the worry not the wind. no idea where some people are getting 70mph gusts from this sort of chart :S

I think you maybe underestimating the strength of the wind because based on the models I have seen so far I would say gusts between 40-60mph is more likely.

Now you may say whats the big deal because the strength of this isn't anything special. Well my answer would be the time of year because if this was Autumn/Winter then the strength of the wind wouldn't be exceptional. However due to the fact that the trees are in full leaf it would only take a gust of wind around 50mph to bring a tree down!.