Convective / Storm Discussion - 8th September onwards 2013

[Jane Louise]

I've been getting my storm risks from the Netweather local forecasts and from Staverton Airport. But I know not to take the storm risk seriously until the actual day.

[Mapantz]

Forgive me if i'm wrong but aren't the forecasts that Wills has been pasting, converted from model data in to readible text? In which case, there's no human input, right? So the last thing you want to do, is actually take it as gospel! The temperature/humidity aspects are likely to be the most accurate but with the sporadic nature of showers this weekend, i wouldn't be saying you have a great chance of storms just because it has a high percentage for your area, wait until nearer the time and start to look at the higher resolution models, and as John says, look for the trends. 

72% chancefor me on Saturday, and fierce! I'm betting on the other 28% 

Edited September 25, 2013 by Mapantz

[YokTok]

Just had a lightning overhead here in Redhill with very impressive thunder... was outside having a ciggie under my umbrella at the time and near pooped myself

[Nick F]

Just had a lightning overhead here in Redhill with very impressive thunder... was outside having a ciggie under my umbrella at the time and near pooped myself

Totally unexpected TBH, but radar and Atd lightning detector concur. No CAPE on GFS, fax shows an upper cold front. Edited September 25, 2013 by Nick F

[Coast]

Totally unexpected TBH

 

+1, I must try harder!! :lol: 

[Coast]

Even the Skew T points to benign: 

 

 

 

 

[Nick F]

Looking at 06z fax and 700-500 hPa theta-w chart for same time - looks like some destabilisation of moist layers aloft by upper cold front moving in from the west this morning - hence elevated convection and alot of Ac Cas with isolated Cbs above this mist this morning:

 

 

GFS not picking up this instability too well.

 

[lfcdude]

 

have you ever tried posting in a non confrontational manner?.....jeez!.......one for the ignore button me thinks

 

 

 

 

Where is the ignore button? After all i don't think many people want to be reading his own netweather home page forecast for his location every day a few times a day.

Edited September 25, 2013 by lfcdude

[paul m]

Wills if you continue with your tantrums i see a 100% chance of you causing storms on here. Dont forget that if you have a 50% chance of a storm there is still 50% chance of nothing. You really need to chill out as you will find yourself as a very unpopular member on here. What does the (25) mean next to your name ?????. Please dont spoil the forums for us all we love coming on here. 

[PolarWarsaw]

I can confirm....that in a small village near Stafford....there's going to be cloud....wind.....rain.....storms.....snow.....sleet....sun....blue sky...... at some point....in the future.... 

 

Thanks. 

PW. 

[wimblettben]

I will agree that William doesn't need to put his place name in his posts as the location name is under the profile picture.

 

But he has every right to put his thoughts down about the chance of storms in a future timescale.

 

I mean, this is a forumn after all.

[Coast]

Of course never say never, but GFS is 'riding the red and orange wave' of slim convective chances in the Manchester and London free atmosphere charts. Is it on to something or is just a big red and orange herring?

 

 

 

[staplehurst]

Looking at 06z fax and 700-500 hPa theta-w chart for same time - looks like some destabilisation of moist layers aloft by upper cold front moving in from the west this morning - hence elevated convection and alot of Ac Cas with isolated Cbs above this mist this morning:

 

fx00_06z.pnggfs_the700_eur6.png

 

GFS not picking up this instability too well.

Fair play to the ECMWF, had picked up the potential as early as last weekend. Initially an outlier, was followed by the UKMO which in recent days seemed to have backed off. The classic problems with modelling mid-level instability...

[Captain Shortwave]

Quite a clump of rain (looks pretty heavy) pushing East across the home counties, maybe London in with a shout of something exciting this evening?

Edited September 25, 2013 by Captain shortwave

[Jane Louise]

Please lets keep on topic! any post that offends anyone please use the report button and please do not use this thread to discuss the complaint. This is a convective/storm discussion thread.Yes! some of us have had nothing much to discuss convective wise this year. But there is still a little hope for the rest of the year yet fingers crossed . 

[Costa Del Fal]

Potential for a little thundery weather for Cornwall and the Channel Islands on Friday through into Saturday? SE Winds are perfect for here and with the sea near enough its warmest for the year too. Who knows... Will pay for all this mist and fog we are enduring down here!

[A.J]

Potential for a little thundery weather for Cornwall and the Channel Islands on Friday through into Saturday? SE Winds are perfect for here and with the sea near enough its warmest for the year too. Who knows... Will pay for all this mist and fog we are enduring down here!

A question of waiting and seeing Luke.......the model outputs have been quite inaccurate for southern parts the past couple days, and I noticed that Ian F on the Points West mentioned that they're struggling with several different scenarios for the weekend period....could be dry, could be quite wet.......12z GFS shows for example infers chances of heavy ppn over northern france (in an airmass of quite strong multi-layer convective potential & lift) drifting across the channel....however lapse rates are poor for storm parameters inferring that there's little forcing and what there is is quickly shunted towards Benelux.......I would normally say wait until the hi-res models come into play, but as today's rainfall show, even they can get it quite wrong at short timescales!

[Costa Del Fal]

A question of waiting and seeing Luke.......the model outputs have been quite inaccurate for southern parts the past couple days, and I noticed that Ian F on the Points West mentioned that they're struggling with several different scenarios for the weekend period....could be dry, could be quite wet.......12z GFS shows for example infers chances of heavy ppn over northern france (in an airmass of quite strong multi-layer convective potential & lift) drifting across the channel....however lapse rates are poor for storm parameters inferring that there's little forcing and what there is is quickly shunted towards Benelux.......I would normally say wait until the hi-res models come into play, but as today's rainfall show, even they can get it quite wrong at short timescales!

True, quite a mess at the minute. NMM does suggest some good instability moving in early Saturday for a time but as we have seen, it will probably change more yet.

[East_England_Stormchaser91]

South coast now is the only place that will see a good chance of a storm I think. Unless we see something special, the chances now are really beginning to pull away as the sun is rapidly losing its strength. Don't get me wrong, I remember getting ready for school one morning in October 2006 I believe, when I could hear loads of short deep rumbles, I thought to myself 'that cannot be thunder surely!' Then the pink sheet lightning was evident! I walked to school and got caught in a horrific storm which in actual fact made the headlines in the local paper about the flash flooding in the town. Half of the class ended up getting to go home as we were that drenched! Memories!! 

So I'm certainly not ruling anything out till October is out, but the odds are definitely decreasing now. If these synoptics were happening mid July, then I would be spilling my drink and going nuts. Just typical that it is the same old deep Southerly that is just too late in the season to produce anything spectacular.

Edited September 25, 2013 by East_England_Stormchaser91

[Supacell]

Next week is looking good on the GFS, and has been for a few runs now. It is a long way off though and not worth getting excited about, but considering we are now heading into October it is still nice to see. Regarding the odds decreasing due to being later in the year, yes I agree the sun is not as strong now as in July, but SST's are warmer than in July. This is likely to favor areas on the coast as opposed to inland though - but next week shows a set up which would bring thunderstorms inland also.

 

One year ago I thought that although it commonly snows in March, the chances of deep snow on the ground surviving more than a couple of hours under the strengthening March sun is minimal, especially later in the month. After last March I will never think like that again. Truth is, in recent years, the start and end dates of our seasons are becoming more blurred in my opinion.

[Coast]

Next week is looking good on the GFS, and has been for a few runs now. It is a long way off though and not worth getting excited about, but considering we are now heading into October it is still nice to see. 

 

As you say, still synoptically a way off, but encouraging signs for October. I'd like to see a bit more daytime heat though.

Edited September 26, 2013 by Coast

[The PIT]

Potential for a little thundery weather for Cornwall and the Channel Islands on Friday through into Saturday? SE Winds are perfect for here and with the sea near enough its warmest for the year too. Who knows... Will pay for all this mist and fog we are enduring down here!

Mentioned this morning by Carol K so that will have put the mockers on it. Too far south for us but somebody may be lucky.

[Coast]

GFS still keeping things to our South:

 

 

 

Maybe a bit of convergence along the Channel facing coasts will pep things up?

 

 

[A.J]

nice to see you back posting!

 

last night, the lapse rates were pretty poor throughout the layers from what I could see, nice to see things are changing for the better in the interim

 

just having a first glance at the GFS12z output.....certainly is some mid-level energy and instability over the far south.....interesting!

Edited September 26, 2013 by ajpoolshark

[TheToastPeople]

I sure hope that big swirly thing out to sea is going to deliver the goods after the weekend