Heavy rain/storms Thurs 19/7 - Sat 21/7

[Andy Bown]

When was the last time that central southern Englang faced such an amount of rain in a short period? Just trying to gauge what sort of impact 50-100mm of rain will have?

Sunday 13th May 2007 saw widespread large rainfall totals across Cornwall, Devon, Somerset, Dorset and Wiltshire. My 24 hour total was 27.5mm but it only rained for about 5 hours.

Then from Sunday 27th into Monday 28th May (also this year) a very active LOW brought a 24 hour total of 43mm!

[suffolkboy_]

Looking at the NetWeather radar, there is already thundery activity within that rain over the Bay of Biscay towards Brest (only the French could call somewhere Brest and not find it funny )

[Supacell]

Sunday 13th May 2007 saw widespread large rainfall totals across Cornwall, Devon, Somerset, Dorset and Wiltshire. My 24 hour total was 27.5mm but it only rained for about 5 hours.

Then from Sunday 27th into Monday 28th May (also this year) a very active LOW brought a 24 hour total of 43mm!

On the 25th June 2007 there was around 90mm of rain in parts of the Peak district which lead to most of the rivers around here bursting there banks.

Back on topic, Saturday now looking good too with an area of wind convergence heading north alongside decent CAPE.

[Bobby]

The valleys seem to be immune to floods. I remember last year when we had about 120mm of rain in 2 days, yet there wasn't any flooding I know of. Nothing serious anyway. Actually I'm not aware a case of serious flooding in my local area, despite the variety of rivers that run down here. The highest I've ever seen the taff is about 2 foot from the top, and that was after about 150mm in 2 days a few years ago. I don't know what it would take to flood here. I am about 70m above the river anyway, so there is no way I could be flooded, apart from a tsunami caused by a huge meteorite impact I suppose.

Edited July 19, 2007 by Magpie

[johnholmes]

Will John Holmes do any of his excellent updates on this situation? Please

nice of you to make that comment. I will try but I'm pretty occupied with various things outside the weather at the moment.

[londonsnow]

i'm surprised the media havent really picked up on this event. too busy with canabis and the cabinet i guess! but this really does look like a headline grabbing scenario.

[johnholmes]

maybe the Thames will overflow and flood London , causing billions of pounds worth of damage and thousands of deaths........

but then, maybe not!

daft and irresponsible comments like that do make we wonder about spending time trying to explain what the weather may do and why.

[03jtrickey]

Hmm,... doesn't look good for Cheltenham!... at least not being at the bottom of the Cotswold escarpment. Could the hills accentuate the rain? Still, should be interesting!

[Somerset Squall]

ITV weather just said this will probably be the most severe weather event this Summer, which means worse than June 25th? I really hope not. I seem to be out of the main area of action but I really don't envy those to my northeast.

And Jimmyay, think before you post eh?

[Noctilucid]

maybe the Thames will overflow and flood London , causing billions of pounds worth of damage and thousands of deaths........

but then, maybe not!

daft and irresponsible comments like that do make we wonder about spending time trying to explain what the weather may do and why.

I agree, theres certainly nothing funny about thousands of people being killed!

Anywho im confused, is rain expected to come from thunderstorms of dynamic rain with convective areas embedded?

Joe

[Vince]

maybe the Thames will overflow and flood London , causing billions of pounds worth of damage and thousands of deaths........

but then, maybe not!

daft and irresponsible comments like that do make we wonder about spending time trying to explain what the weather may do and why.

tell me about it ....please John would really apprieciate one of you specials, given the circumstances. in times like this a common sense approach is needed

[Just Before Dawn]

It would have to be quite extraordinary to be more severe than June 25th, which was extremely grim (and, lets not forget still is for a very large number of people).

Hopefully it won't be quite that severe, though the synoptics and the messages coming out of the Met Office do sound pretty grim.

I'd also second the comment about John's compelling commentary - If you can find time John, I know it would be very much appreciated by a whole load of us.

[Geordiesnow]

I agree, theres certainly nothing funny about thousands of people being killed!

Anywho im confused, is rain expected to come from thunderstorms of dynamic rain with convective areas embedded?

Joe

i doubt 1000s will be killed so don't know where you got that one from?

There could be some thunderstorms embedded but the beeb seem to focus on the intensity of the rain rather than anything else so just wait and see.

Sorry jshaw forget what i said about the 1000s being killed , i know why you said that now.

Edited July 19, 2007 by Geordiesnow

[Rustynailer]

The valleys seem to be immune to floods. I remember last year when we had about 120mm of rain in 2 days, yet there wasn't any flooding I know of. Nothing serious anyway. Actually I'm not aware a case of serious flooding in my local area, despite the variety of rivers that run down here. The highest I've ever seen the taff is about 2 foot from the top, and that was after about 150mm in 2 days a few years ago. I don't know what it would take to flood here. I am about 70m above the river anyway, so there is no way I could be flooded, apart from a tsunami caused by a huge meteorite impact I suppose.

There is a village called Rainow just NE of Macclesfield it is on the edge of the Peak district on the side of a very large hill. Alt 220m.

When I was young I went into the village pub with my Father to see the line on the wall from the great flood in the 30s I think.

The line reached by the water was up to my dads chest he is 5'9". There was a similar flood in the 90s some villages in the peak district called Wildboarclough and Bosley and the surrounding area, I saw first hand the washed out bridges a few weeks later.

It is possible just about anywhere, you would be as surprised as I was if you saw it no doubt

Regards,

Russ

Edited July 19, 2007 by Rustynailer

[suffolkboy_]

Since JohnHolmes posted a comment complaining about Jimmyay's comment, everybody has started ganging up on him, very unfair, lets get back to what could be a memorable rain event for the south.

It is this sort of setup which is really quite exiting. Models generally struggle with this kind of setup, most of it depends on nowcasting. Quie often, it ends up being a downgrade, with it not looking as bad as it forst did, but could this be one of those cases when it worse than predidcted? eg the front stalls? I can't wait!

[Noctilucid]

Since JohnHolmes posted a comment complaining about Jimmyay's comment, everybody has started ganging up on him, very unfair

erm, i agreed with him One post by someone else isnt exactly ganging up on someone is it?

Joe

[Bobby]

- Tomorrow risk as I see it. I don't think flooding will be widespread, not like it was up north in recent weeks, but there is a fair risk of localised flooding.

My crappy weather risk maps are back! Go to my signature link for more info.

[Noctilucid]

i doubt 1000s will be killed so don't know where you got that one from?

There could be some thunderstorms embedded but the beeb seem to focus on the intensity of the rain rather than anything else so just wait and see.

Sorry jshaw forget what i said about the 1000s being killed , i know why you said that now.

Thanks for the info, maybe the beeb/metoffice are just covering themselves incase there is significant thundery activity, it seems the last few severe thunder events have schocked them into a state of alertness, before they were very reluctant to mention thundery activity, now they tend to forecast it quite well.

Theaccuracy of the beeb has certainly improved, they almost got it completely correct today except the showers werent/arent so widespread.

Joe

[johnholmes]

I agree, theres certainly nothing funny about thousands of people being killed!

Anywho im confused, is rain expected to come from thunderstorms of dynamic rain with convective areas embedded?

Joe

a mix is the easy answer!

Much of it will be dynamic(frontal) but with convective elements embedded in it, both ahead of and in the frontal belt itself.

I will try and make time to do my take on the situation later this evening.

It is, in my view, another situation where its impossible to be precise even this near as to how much rain will fall and just where the heaviest falls will be. I do not think it is quite as bad a situation, in terms of rainfall amount and the total area it will affect, as the last serious one for the Sheffield/Rotherham/Doncaster/Hull area was.

It would seem, at the moment that its an area to the south of that one which could be worst affected. That is serious enough when you look at the source of the river Severn and its various tributaries, and possibly the Trent also. In each case along their banks then flooding would be possible if not probable IF the rainfall occurs in the areas mentioned above.

Like I mentioned at the beginning I'll try and do my 'take' on it later this evening. by then the satellite and pressure changes should be starting to show where the most likely areas could be.

Edited July 19, 2007 by johnholmes

[WS Evolution]

There are currently 35 Flood Watch's in force and 5 flood warnings. Many of which have been issued this afternoon / evening. With the ground already saturated in many areas the flooding could be quite server. I don't think the amount of rain by its self is going to be the problem, its where there has already been heavy rain for weeks and weeks that there is going to be problems.

The suggestion from most sources is that the midlands south will be at the greatest risk, but it would not take very much to push the worst of the weather further north into Yorkshire, where it would be a disaster.

Is it possible to get an accumulation map for days rather than hours??

[Bobby]

Is it possible to get an accumulation map for days rather than hours??

Those shows the rain expected to fall between now and next Wednesday. Most of that will be tomorrow.

[tinybill]

Since JohnHolmes posted a comment complaining about Jimmyay's comment, everybody has started ganging up on him, very unfair, lets get back to what could be a memorable rain event for the south.

It is this sort of setup which is really quite exiting. Models generally struggle with this kind of setup, most of it depends on nowcasting. Quie often, it ends up being a downgrade, with it not looking as bad as it forst did, but could this be one of those cases when it worse than predidcted? eg the front stalls? I can't wait!

i think it will be the middle of the country turn for the main event just beemn watching bbc new 24 any were could easily get 4 inches of rain, any one who living in low areas my advice to-night get the sand bags ready looks like thing will get they nasty later on friday

Edited July 19, 2007 by tinybill

[WS Evolution]

Those shows the rain expected to fall between now and next Wednesday. Most of that will be tomorrow.

Thanks , but I was thinking the past few days or even weeks rather than predictions.

Edited July 19, 2007 by WS Evolution

[Doc]

Looking at the NetWeather radar, there is already thundery activity within that rain over the Bay of Biscay towards Brest (only the French could call somewhere Brest and not find it funny )

I spent a WEEK in Brest a couple of years ago and it certainly is NOT funny!

Incidentaly, the last dry day here (at my location) was June 17th! I'd nearly now be disappointed if I didn't get rain every day for the rest of the summer!!!

Edited July 19, 2007 by Doc

[The PIT]

At the Moment it looks like the worst effected areas will be between 50 to 100 miles south of Sheffield. Of course this could all change depending on how far North it pushes initially. Since it's being raining here nearly everyday for 20 odd days, mostly small amounts the catchment areas are probably still close to being saturated so another 60 80 mm would mean a return of the floods. Minor flood will occur due to poor maintenance and neglect by our council with much lower amounts of rain. So you'll understand why I want this rain to fall anywhere but here.

The largest rainfall event for Sheffield occured between the 13th,14th and 15th of June. If this hadn't had happened the Floods in Sheffield would have been very much smaller as the rainfall that fell for us 40 odd mm wasn't a rare event. However two close together is.

So now need Mr Data to see if anything like this has happened before. Three large rain events in just over a month. If it hasn't it'll be something to tell your Grand children years from now.

So far we've had four large rain events forecast two have turned up the others haven't is the fifth going to arrive or is going to be much noise about nothing special. Time will tell.