Convective / Storm Discussion - 8th September onwards 2013

[NO LONGER POSTING]

Not anymore.

Here comes the thunderstorm!

 

thunderstorm.jpg

 

http://www.blitzortung.org/Webpages/index.php?lang=en&subpage_0=12

 

Wouldn't get your hopes up Im afraid

[Mark Neal.]

Some lightning strikes out to sea in the Channel as that band of heavy rain moves up.

[NO LONGER POSTING]

Some lightning strikes out to sea in the Channel as that band of heavy rain moves up.

 

New strikes now looking good for you guys hope it holds up!

[Coast]

There seems to be a tickle on down off the SW coast, but will it get inland through the next few hours??

 

[The PIT]

Yup the old rumble and bang forecast for the lucky sw again.

[East_England_Stormchaser91]

All this potential will not even come close to the 23rd July. Not getting hopes up at all! 

I'm done with the storm hoping for this year about now as the potential just isn't there. No point at all after the equinox IMO, except the coastal regions. Brrrring on winter and the thundersnow! I will be back storm hunting next spring.

[Supacell]

All this potential will not even come close to the 23rd July. Not getting hopes up at all! 

I'm done with the storm hoping for this year about now as the potential just isn't there. No point at all after the equinox IMO, except the coastal regions. Brrrring on winter and the thundersnow! I will be back storm hunting next spring.

 

I think we would struggle to match the 23rd July in the middle of summer

[East_England_Stormchaser91]

I think we would struggle to match the 23rd July in the middle of summer

True, very true indeed. Still cannot stop revisiting the storm thread that night. Those elevated storms you pointed out giving the spectacular lightning, I was right under the lot of that! It was simply staggering, the rain even more so, our whole garden got flooded and the driveway was a river.

That night will stick in my mind until the day I die!  

Hope for some similar stuff next summer. Until then, time to get the snowshoes and snow tyres on standby! Hoping for some Wash streamers and prolonged blizzards this winter.

[A.J]

convective stuff in the south west fizzling out readily, just a band of narrowing showery rain currently.....interesting to see if it intensifies during the overnight hours and more moisture is advected northwards into central/southern UK

[Stuart]

Synopsis

An upper ridge over the North Sea will continue to slowly drift eastwards towards Scandinavia, allowing an upper trough over the Atlantic to approach from the west. The net result is a strengthened southerly flow, allowing fronts to make more progress eastwards compared to recent days, albeit weakening all the while.

 

Discussion

Showery rain along an occlusion will contain a mixture of dynamic and convective rainfall as it drifts northeastwards across Britain through the first half of the forecast period. Limited (if any) lightning activity is expected with this feature.... WALES, WEST COUNTRY ...Behind the occlusion, in the post-frontal airmass, surface-based convection is forecast to develop as insolation improves through the day, generating some 400-600 J/kg CAPE. Given such instability and ELTs down to -40C, some lightning activity is expected with stronger cells, particularly over Wales where orographic forcing may aid forced ascent. DLS is rather weak, around 20kts, however backed surface winds coupled with some low-level shear and helicity suggests that some organised cells may exhibit supercellular characteristics, capable of producing hail locally >1.0cm in diameter, and perhaps a funnel or weak tornado, especially given rather low LCLs. Some localised flooding is possible from torrential downpours since PWAT values will be near 30mm.... IRELAND ...Similar conditions/evolution are forecast to Wales and the West Country, albeit with the greatest probability for lightning across the southern half of the SLGT, convection rather more isolated further north. Have included a large SLGT to cater for northward expansion of convection through the late afternoon/evening hours.

 

http://ukasf.co.uk/storm-forecasts/283

 

[Dorsetbred]

Nowt but drizzle here, the band of precip has a hole miles wide in it, and guess where we are? Right in the middle of the gap, with nowt.

[butler_son]

Nowt but drizzle here, the band of precip has a hole miles wide in it, and guess where we are? Right in the middle of the gap, with nowt.

 

To be fair the rain we've got isn't exactly biblical, even if it is fairly heavy.

[ZONE 51]

Didn't experience much activity here (west London) had heavy line of rain. Some very active downpours were across western zones though-this line of intense cells of rain is to the east and north of London now. The eastern zone of this rain over towards EA for example, has become very much heavier and more organized over the last hour.

Edited October 2, 2013 by ElectricSnowStorm

[ZONE 51]

Potential widespread UK very wet weather Thursday into Friday charts are for tomorrow and a few hours into early Friday , risk of heavy thunderstorms southern England perhaps Wales, risk highest SE England I think, flooding problems likely in places -  data GFS 00z) latest update:

Theta-E 850 hpa (Equiv Pot T)^^^ 1200/1800hrs (note the 50 red lined area)

Theta-W 850(wet bulb pot T)^^^ 1200/1800hrs (note the 16-18C purple lined area)

 

Convection cloud cover and souring index ^^^ 1200hrs (note the green zone lined area)

 

Cape ^^^ 1500hrs (note imported thunderstorm risk) look at the lifted index, instability/increasingly humid warm layer)

 

(The next lifted index chart is for night-time!!!)

Lifted Index ^^^ 1200hrs >> 0000hrs)

Thickness 850/1000hpa ^^^ 0000hrs - warm humid layer

Wind 10m Kts(surface wind) ^^^ 1800hrs S/SE flow

Wind 850 (kts) ^^^ 2100hrs S/SW

Increasing dew points to late night!! (see next chart)

Dew points Temp 2m ^^^ 16-17C increasingly to late eve/night

 

Surface Temps 2m ^^^ up to 17C (18-20C day-time possible) late eve into night-time warm and humid.

 

ES.

Edited October 2, 2013 by ElectricSnowStorm

[wimblettben]

Somethings got to give with this next very heavy band of rain tomorrow shurely!

 

As usual just some rain last night, nothing thundery.

[Coast]

GFS shows an isolated storm in the Irish Sea that doesn't look like it makes land today:

 

 

But there seems to be a lot of rain and maybe some hail coming into the West later:

 

 

 

 

 

Lots of moisture up there:

 

 

Hail?

 

[Cakie]

Already had some short, heavy showers. Fingers crossed something more could develop later

[Coast]

Some quite intense rain at least for the SE tomorrow, if NMM has it forecast correctly:

 

[Supacell]

Some quite intense rain at least for the SE tomorrow, if NMM has it forecast correctly:

Hopefully this area would expand north and west during the evening and night to give more places a chance of something thundery....possibly.

[Guest William Grimsley]

Nothing thundery last night. But, with the strong E wind and high rainfall rates, listening to the rain lashing on lounge windows, was lovely, here.

[Mapantz]

Some quite intense rain at least for the SE tomorrow, if NMM has it forecast correctly:

 

 

It will be interesting to see how it performs as the WRF model that Matt Hugo has just posted shows that thundery area of rain a good 100 miles further West. :O

[Coast]

So lets chuck GFS into the mix and they have it to the East, but mostly out in The Channel for the heavy stuff:

 

Edited October 2, 2013 by Coast

[Mapantz]

So lets chuck GFS into the mix and they have it to the East, but mostly out in The Channel for the heavy stuff:

 

 

 

 

I'm definitely disregarding the GFS, particularly the 00Z :lol: If that run was to believed, most of Southern England and Wales will be seeing barely a few mm's tomorrow.  I'll be interested to see how yellow warning from the Met Office changes today, that should be updated slightly. I'm off for now, i have my diabetic check-up - I may not have to inject anymore as i've started producing insulin. :O bbiab. 

[Guest William Grimsley]

True, very true indeed. Still cannot stop revisiting the storm thread that night. Those elevated storms you pointed out giving the spectacular lightning, I was right under the lot of that! It was simply staggering, the rain even more so, our whole garden got flooded and the driveway was a river.

That night will stick in my mind until the day I die!

Hope for some similar stuff next summer. Until then, time to get the snowshoes and snow tyres on standby! Hoping for some Wash streamers and prolonged blizzards this winter.

I don't remember 23/07/2013 as being a very eventful day. I think it was just showers. I will never forget the 10 minute thunderstorm 02/08/2013 and the 4 hour thunderstorm 28/09/2013, here. 02/08/2013: High Rainfall Rate 02/08/2013: 117.6 mm/hr 21:14 High Hourly Rainfall 02/08/2013: 2.2 mm 21:16 Rainfall 02/08/2013: 2.2 mm. 28/09/2013: High Rainfall Rate 28/09/2013: 8.6 mm/hr 09:01 High Hourly Rainfall 28/09/2013: 5.6 mm 08:38 Rainfall 28/09/2013: 13.8 mm.

[staplehurst]

I don't remember 23/07/2013 as being a very eventful day. I think it was just showers. I will never forget the 10 minute thunderstorm 02/08/2013 and the 4 hour thunderstorm 28/09/2013, here. 02/08/2013: High Rainfall Rate 02/08/2013: 117.6 mm/hr 21:14 High Hourly Rainfall 02/08/2013: 2.2 mm 21:16 Rainfall 02/08/2013: 2.2 mm. 28/09/2013: High Rainfall Rate 28/09/2013: 8.6 mm/hr 09:01 High Hourly Rainfall 28/09/2013: 5.6 mm 08:38 Rainfall 28/09/2013: 13.8 mm.

 

Presumably you mean down in Devon? http://www.ukasf.co.uk/storm-forecasts/257 Click on the lightning overlay ha - a very active day, particularly in the early hours through to mid-morning. Sadly very little in this corner of Kent on that particular day.