Convective / Storm Discussion - 8th September onwards 2013

[Jane Louise]

Fine I was stating your own websites words...

No need to get narky Wills, I say it again, no need to mention N---t--- p in every Post that's all I ask  cheers Will.... Good luck for your area on Saturday, you've probably got more chance then me. It never happens here  anyway lol

[Guest William Grimsley]

No need to get narky Wills, I say it again, no need to mention N---t--- p in every Post that's all I ask  cheers Will.... Good luck for your area on Saturday, you've probably got more chance then me. It never happens here  anyway lol

Sorry Jane Louise.... Thanks and you, yeah I probably have. Same here the only good thunderstorm activity was at the end of July, start of August and the start of September, here.

[A.J]

 

 

Sometimes, one feels like not just banging one's head against a brick wall, rather smashing straight through it!

[IanR]

That express story, oh dear ,oh dear, oh dear, 'Fierce'   what a load of  utter tosh, I will platt dry sawdust if there is anything remotely 'Fierce'   what will really happen is there will be periods of rain or showers for places and there MIGHT be the odd rumble of thunder mixed in for a couple of select places, but mostly it will be non electrical rain for the majority 

 

Its so easy to write the script thesedays for these events, seen it time and time again and I am always right

 

And another 100 percent accurate prediction from me ,,,,, there will be no 'Fierce' thunderstorms here or any other type of thunderstorm

 

Then again I  suppose if anywhere in the UK gets more than 3 rumbles from a shower I suppose it could be classed as 'Fierce' by todays standards

Edited September 24, 2013 by IanR

[Guest William Grimsley]

 

 

Sometimes, one feels like not just banging one's head against a brick wall, rather smashing straight through it!

Why?

That express story, oh dear ,oh dear, oh dear, 'Fierce'   what a load of  utter tosh, I will platt dry sawdust if there is anything remotely 'Fierce'   what will really happen is there will be periods of rain or showers for places and there MIGHT be the odd rumble of thunder mixed in for a couple of select places, but mostly it will be non electrical rain for the majority 

 

Its so easy to write the script thesedays for these events, seen it time and time again and I am always right

 

And another 100 percent accurate prediction from me ,,,,, there will be no 'Fierce' thunderstorms here or any other type of thunderstorm

 

Then again I  suppose if anywhere in the UK gets more than 3 rumbles from a shower I suppose it could be classed as 'Fierce' by todays standards

Yeah, it's doubtful that any of these bands of showers/thundery showers will be fierce. The Daily Express like many other newspapers, just want to hype it up. So, we get scared.

[johnholmes]

Really? Sat 28/09 16:00 to 19:00: Temperature: 17°C Humidity: 85% Dew Point: 15°C CAPE: 766 j/kg Lifted Index: -3 Precipitiation: 6.51 mm Heavy Convective Precipitation: 6.32 mm Convective Cloud: 96% Storm Risk: 52%.

Sat 28/09 19:00 to 22:00: Temperature: 15°C Humidity: 94% Dew Point: 14°C CAPE: 396 j/kg Lifted Index: -1 Precipitiation: 4.95 mm Light Convective Precipitation: 4.2 mm Convective Cloud: 10% Storm Risk: 37%.

 

A bit lower than yesterday. But, still promising.

 

 

Willaim it is a computer prediction and it is several days away. Getting the isobars correct that far out is much easier than getting will it rain/thunder/snow that far out. Don't take the model output as gospel, watch for trends that far out, if they are kept each run for several days then they may turn out not far from the actual. TS are, unless major storm areas very very small in terms of the model output.

[Guest William Grimsley]

Willaim it is a computer prediction and it is several days away. Getting the isobars correct that far out is much easier than getting will it rain/thunder/snow that far out. Don't take the model output as gospel, watch for trends that far out, if they are kept each run for several days then they may turn out not far from the actual. TS are, unless major storm areas very very small in terms of the model output.

Yes, I agree with you. The UK storm risk chart and the UK CAPE+Lifted Index chart are supposed to give a guesstimate of where the thunderstorms might be.

[Supacell]

I now have one half closed eye on the possible weather this weekend but nothing more than that. My one eye (which is the left one) will fully open if the weekend is still looking promising from a thundery prospective come Thursday. Both eyes will be open wide when I can see the flashes of lightning approaching and hear distant growls of thunder.

 

As for fierce thunderstorms, the only thing that is fierce is the overwhelming smell of bull manure that comes out of that newspaper.

[wimblettben]

How about we all just wait and see!

 

Seriously though, William is only talking about what may occour over the weekend. Nothing wrong with that.

Edited September 24, 2013 by wimblettben

[Guest William Grimsley]

How about we all just wait and see!

 

Seriously though, William is only talking about what may occour over the weekend. Nothing wrong with that.

Yeah something might even happen tonight by the looks of the skies!

Thank you, wimblettben.

[Guest William Grimsley]

This is very interesting and positive, too.

 

Sat 28/09 13:00 to 16:00: Temperature: 18°C Humidity: 64% Dew Point: 11°C CAPE: 421 j/kg Lifted Index: -3 Precipitation: 0 mm None Convective Precipitation: 0 mm Convective Cloud: 26% Storm Risk: 32%.

 

Sat 28/09 16:00 to 19:00: Temperature: 16°C Humidity: 79% Dew Point: 12°C CAPE: 520 j/kg Lifted Index: -2 Precipitation: 5.69 mm Heavy Convective Precipitation: 5.51 mm Convective Cloud: 57% Storm Risk: 52%.

 

Sat 28/09 19:00 to 22:00: Temperature: 15°C Humidity: 86% Dew Point: 12°C CAPE: 499 j/kg Lifted Index: -2 Precipitation: 3.81 mm Moderate Convective Precipitation: 3.1 mm Convective Cloud: 87% Storm Risk: 43%.

 

Sat 28/09 22:00 to 01:00: Temperature: 14°C Humidity: 97% Dew Point: 14°C CAPE: 347 j/kg Lifted Index: -1 Precipitation: 4.29 mm Moderate Convective Precipitation: 1.72 mm Convective Cloud: 18% Storm Risk: 77%.

Edited September 24, 2013 by William Grimsley

[Biggin]

Today:

Storm Risk: 0%

Tomorrow Storm Risk 0%

 

Thu 26/09 Storm Risk 0%

 

Fri 27/09 Storm Risk 0%

 

Sat 28/09 Storm Risk 0%

 

Oh well!!

Edited September 24, 2013 by Biggin

[A.J]

 

This is very interesting and positive, too.

 

Sat 28/09 13:00 to 16:00: Temperature: 18°C Humidity: 64% Dew Point: 11°C CAPE: 421 j/kg Lifted Index: -3 Precipitation: 0 mm None Convective Precipitation: 0 mm Convective Cloud: 26% Storm Risk: 32%.

 

Sat 28/09 16:00 to 19:00: Temperature: 16°C Humidity: 79% Dew Point: 12°C CAPE: 520 j/kg Lifted Index: -2 Precipitation: 5.69 mm Heavy Convective Precipitation: 5.51 mm Convective Cloud: 57% Storm Risk: 52%.

 

Sat 28/09 19:00 to 22:00: Temperature: 15°C Humidity: 86% Dew Point: 12°C CAPE: 499 j/kg Lifted Index: -2 Precipitation: 3.81 mm Moderate Convective Precipitation: 3.1 mm Convective Cloud: 87% Storm Risk: 43%.

 

Sat 28/09 22:00 to 01:00: Temperature: 14°C Humidity: 97% Dew Point: 14°C CAPE: 347 j/kg Lifted Index: -1 Precipitation: 4.29 mm Moderate Convective Precipitation: 1.72 mm Convective Cloud: 18% Storm Risk: 77%.

 

where are you getting those figures from?......NW Extra forecasts which use gfs modelling & higher resolution modelling, for example shows nothing of the sort for saturday for a certain village near Sidmouth....no more than 100j/kg for surface based CAPE with a lifted index of +5 (meaning that there is very little bouyancy in the lower levels) and fairly shallow lapse rates.....those parameters suggest the chances of thunderstorms or even slight convection to be very limited.....there is very little mixed layer CAPE, again with positive 4 layer lapse rates, meaning that elevated convection is very unlikely at this juncture

Edited September 24, 2013 by ajpoolshark

[Panayiotis]

Anyone seen the rain on the radar? Seems convective with the GFS, HIRLAM and NAE not showing it all. Can anyone give an insight?

 

[Guest William Grimsley]

where are you getting those figures from?......NW Extra forecasts which use gfs modelling & higher resolution modelling, for example shows nothing of the sort for saturday for a certain village near Sidmouth....no more than 100j/kg for surface based CAPE with a lifted index of +5 (meaning that there is very little bouyancy in the lower levels) and fairly shallow lapse rates.....those parameters suggest the chances of thunderstorms or even slight convection to be very limited.....there is very little mixed layer CAPE, again with positive 4 layer lapse rates, meaning that elevated convection is very unlikely at this juncture

The thunderstorm risk for, here...

[Coast]

GFS currently touting just heavy rain for Saturday with any action more to the South now:

 

 

 

 

If this pans out I shall be staring at the English Channel again looking for flashes on the horizon  

[Guest William Grimsley]

There is a better chance of thunderstorms for Saturday and Sunday, now.
 

Sat 28/09 04:00 to 07:00: Temperature: 13°C Humidity: 87% Dew Point: 11°C CAPE: 880 j/kg Lifted Index: -5 Precipitation: 0.33 mm V Light Convective Precipitation: 0.33 mm Convective Cloud: 10% Storm Risk: 80%.

 

Sat 28/09 07:00 to 10:00: Temperature: 13°C Humidity: 88% Dew Point: 11°C CAPE: 961 j/kg Lifted Index: -5 Precipitation: 0.48 mm V Light Convective Precipitation: 0.48 mm Convective Cloud: 18% Storm Risk: 80%.

 

Sat 28/09 10:00 to 13:00: Temperature: 15°C Humidity: 88% Dew Point: 13°C CAPE: 750 j/kg Lifted Index: -4 Precipitation: 2.01 mm Moderate Convective Precipitation: 2.0 mm Convective Cloud: 12% Storm Risk: 52%.

 

Sat 28/09 13:00 to 16:00: Temperature: 16°C Humidity: 87% Dew Point: 14°C CAPE: 572 j/kg Lifted Index: -2 Precipitation: 3.74 mm Moderate Convective Precipitation: 3.47 mm Convective Cloud: 33% Storm Risk: 45%.

 

Sat 28/09 16:00 to 19:00: Temperature: 17°C Humidity: 83% Dew Point: 14°C CAPE: 306 j/kg Lifted Index: -1 Precipitation: 3.84 mm Moderate Convective Precipitation: 3.06 mm Convective Cloud: 75% Storm Risk: 57%.

 

Sat 28/09 19:00 to 22:00: Temperature: 16°C Humidity: 85% Dew Point: 13°C CAPE: 461 j/kg Lifted Index: -2 Precipitation: 6.66 mm Heavy Convective Precipitation: 4.57 mm Convective Cloud: 52% Storm Risk: 37%.

 

Sat 28/09 19:00 to 22:00: Temperature: 16°C Humidity: 85% Dew Point: 13°C CAPE: 461 j/kg Lifted Index: -2 Precipitation: 6.66 mm Heavy Convective Precipitation: 4.57 mm Convective Cloud: 52% Storm Risk: 37%.

 

Sun 29/09 22:00 to 01:00: Temperature: 15°C Humidity: 91% Dew Point: 14°C CAPE: 220 j/kg Lifted Index: -1 Precipitation: 2.95 mm Moderate Convective Precipitation: 2.55 mm Convective Cloud: 10% Storm Risk: 32%.

 

Sun 29/09 01:00 to 04:00: Temperature: 15°C Humidity: 93% Dew Point: 14°C CAPE: 226 j/kg Lifted Index: 0 Precipitation: 0.22 mm V Light Convective Precipitation: 0.22 mm Convective Cloud: 11% Storm Risk: 32%.

 

Sun 29/09 07:00 to 10:00: Temperature: 14°C Humidity: 96% Dew Point: 13°C CAPE: 582 j/kg Lifted Index: -3 Precipitation: 0.0 mm None Convective Precipitation: 0.0 mm None Convective Cloud: 15% Storm Risk: 26%.

 

Sun 29/09 19:00 to 22:00: Temperature: 16°C Humidity: 93% Dew Point: 15°C CAPE: 564 j/kg Lifted Index: -2 Precipitation: 0.41 mm V Light Convective Precipitation: 0.41 mm Convective Cloud: 7% Storm Risk: 65%.

GFS currently touting just heavy rain for Saturday with any action more to the South now:

 

 

 

 

If this pans out I shall be staring at the English Channel again looking for flashes on the horizon

Oh yes!

[A.J]

The thunderstorm risk for, here...

are you talking about the NW home page 7 day forecast?.....if so, it uses a beta model (NMM-18) so I can't vouch for its verification stats.....even so, it still doesn't explain where you're getting your CAPE & LI figures from...........best advice I can give is to take the values shown for your location with a huge pinch of salt and use the freely available GFS & ECMWF charts and use them in conjunction to the Met Office FAX charts to get a better perspective on storm potential.......regardless of what you've just posted above, the storm parameters using the more in depth NetWeather Extra data suggests storm potential to be no more than very  slight....sorry 

[Coast]

There is a better chance of thunderstorms for Saturday and Sunday, now.  

 

I think on current model runs there is much less of a chance? (unless you are going to France :lol: )

[Guest William Grimsley]

are you talking about the NW home page 7 day forecast?.....if so, it uses a beta model (NMM-18) so I can't vouch for its verification stats.....even so, it still doesn't explain where you're getting your CAPE & LI figures from...........best advice I can give is to take the values shown for your location with a huge pinch of salt and use the freely available GFS & ECMWF charts and use them in conjunction to the Met Office FAX charts to get a better perspective on storm potential.......regardless of what you've just posted above, the storm parameters using the more in depth NetWeather Extra data suggests storm potential to be no more than very  slight....sorry 

Then, what is the point of using 'inaccurate' storm risks on your forecasts, then! I've used the 7 day weather forecast and it's been very accurate.

I think on current model runs there is much less of a chance? (unless you are going to France )

Even looking at the models there is a good chance.

Edited September 25, 2013 by William Grimsley

[A.J]

Then, what is the point of using 'inaccurate' storm risks on your forecasts, then! I've used the 7 day weather forecast and it's been very accurate.

Even looking at the models there is a good chance.

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

[Supacell]

No storm forecast is accurate 3-4 days out i'm afraid. By the time Saturday comes things could look better for more of us or be non existent.

If i am honest the current outputs show the action staying to the south of the uk this weekend but still plenty of chances possible next week if we remain between LP to the SW and HP to the east drawing up muggy, unstable air from the continent.

Edited September 25, 2013 by Supacell

[Coast]

No storm forecast is accurate 3-4 days out i'm afraid. By the time Saturday comes things could look better for more of us or be non existent.

 

Unless you read the Express.....

 

FIERCE thunderstorms are set to lash parts of Britain by the weekend after a run of hot and sultry days, forecasters warned last night.

 

A combination of temperatures above average for the time of year and intense humidity will trigger the widespread torrential downpours. Before the storms hit, muggy conditions could see the air feel like 86F (30C) in parts of the South. Temperatures in many parts will be in the 70s.

 

The unusually hot weather is thanks to hot air sweeping across the UK from the Azores in the Atlantic. Jonathan Powell, forecaster for Vantage Weather Services, said: “It is going to feel very muggy and close, with the heat and humidity likely to trigger thundery outbursts by the end of the week. “This could bring some heavy downpours especially across the North. Parts of the South may escape with showers this week. “It is going to feel hotter as the week goes on with temperatures hitting 77F.†An effect like wind chill in reverse will make isolated spots in the South feel like it is as high as 86F, he added. But he warned: “Next week much of the country could see much heavier downpours with the chance of gales in parts.â€

 

The Met Office also said much of the UK will be hit by “heavy and persistent†rain next week with parts of the country at risk of gale-force winds. A spokesman said: “The weather is likely to turn increasingly unsettled through the weekend with showers or longer spells of rain across the UK. storms The week will end in Atlantic storms, strong winds and thundery downpours. The unsettled regime looks likely to continue thereafter with rain or showers that may be heavy with the risk of thunder. “The rain is likely to be heaviest across the South and East at first before transferring to more northern and western areas.†

 

James Madden, forecaster for Exacta Weather, said: “The second half of the week is likely to bring a more unsettled theme. This blast of warmer weather is likely to be replaced by an October period that will turn progressively cooler.†He said stormy weather conditions will be accompanied by “some very strong and potentially damaging winds at times.†Jim Dale, forecaster for British Weather Services, said: “We are expecting some decent warm weather this week. But it is all going to end in tears with the arrival of Atlantic storms, strong winds and thundery downpours.

 

“It is a real mixed bag.â€

 

http://www.express.co.uk/news/uk/431689/Fierce-thunderstorms-set-to-lash-parts-of-Britain-by-the-weekend

 

So a dramatic headline with little real substance and then an article which only quotes at best, a risk of thunder but plenty of rain?

[Chris K]

Nearly spat my drink out at that article. If anything it has been slowly downgrading over the last day or two on the models for anything "fierce".

 

At best I reckon there may be a few sferics pop up to our South in the channel with perhaps some "fierce" drizzle for some as (if) it moves across.

[johnholmes]

amongst all the hype just when and where are any storms predicted someone please?

then perhaps we can actually look carefully at the model outputs and see how likely they are?