Convective / Storm Risk Discussion - 21st June 2013 onwards

[jmatt]

Clouds have covered the sky, sun hidden from view but still hot and humid. Wind has shifted direction too

[Supacell]

It is stifling here at 29c with a dp at 16c. Those showers/storms in N England are moving very slowly but i am hopeful for more to develop over the next couple of hours.

[Thundery wintry showers]

I was going to go to Thirsk today..wish I had now..

 

Sharp shower here just a couple of miles away from Thirsk, no thunder as yet though.  The radar shows a second echo to the west of this one which is producing numerous sferics, so it all depends on whether it can keep much intensity.  I wasn't expecting to catch any of today's showery activity at all though!

[Nick F]

Netweather storm forecast http://www.netweather.tv/index.cgi?action=convective;sess=

 

Wind maps show nicely the convergence zone over NE England which is likely to be creating the lift for the line of storms:

 

 

12z Nottingham/Watnall radiosonde ascent showing steep lapse rates and CAPE between 700 and 400 hPa, a cap below this preventing parcels from rising, though given lift from convergence and/or temps reaching 29-30C, the cap likely to be overcome.

Edited July 13, 2013 by Nick F

[pottyprof]

I'm thinking about lowering the lightning attractors.  Ham radio is a great hobby but the antenna farm isn't a good idea when storms are forecast,

[Wet'n'Dry]

I'm thinking about lowering the lightning attractors.  Ham radio is a great hobby but the antenna farm isn't a good idea when storms are forecast,

 

I also used to do the same, somehow a lightning arrestor on a length of RG213 gave me no confidence, in fact it scared the beejesus outta me!!

[johnholmes]

The Watnall 12z ascent shows with T= 30C and Td=15C that the 'nose' can be broken, the way is then open to 39-40,000ft, see below

http://weather.uwyo.edu/cgi-bin/sounding?region=europe&TYPE=GIF%3ASKEWT&YEAR=2013&MONTH=07&FROM=1312&TO=1312&STNM=03354

Doncaster airport is showing 30 and 16C. There is also a convergence developing due to the Lincs sea breeze starting so somewhere in Lincs, S Yorks, N Derbys or N Notts would seem liable to something.

In fact looking at the surface wind arrows on XC Weather there are minor convergence zone developing in a whole number of places.

sorry Nick beat me to it again, serve me right for not looking more than 1 post above me!

Edited July 13, 2013 by johnholmes

[pottyprof]

I also used to do the same, somehow a lightning arrestor on a length of RG213 gave me no confidence, in fact it scared the beejesus outta me!!

 

It doesn't help that the local school is in the next street and their boiler chimney has been hit every time we've had a local storm since it was installed.  

[Tim B]

I can see that storm in the north out of my window, a bit hazy though so I'm not sure if it would show up in a picture.

[johnholmes]

the Cu overhead is still relatively shallow, mainly Cu type 1 but there are one or two Cu type 2 have developed in the last 30 minutes or so.

[gottolovethisweather]

Netweather storm forecast http://www.netweather.tv/index.cgi?action=convective;sess=

 

Wind maps show nicely the convergence zone over NE England which is likely to be creating the lift for the line of storms:

 

wind_15z.png

windmap_15z.gif

 

12z Nottingham/Watnall radiosonde ascent showing steep lapse rates and CAPE between 700 and 400 hPa, a cap below this preventing parcels from rising, though given lift from convergence and/or temps reaching 29-30C, the cap likely to be overcome.

 

Bottes won't be happy with that last chart.

[DAVID SNOW]

Storm? popped up just north of Leicester.

[weatherobsuk]

A nice beefy CU over Sheffield (visually seen here) turning into a TCU soon if the latest radar is to be believed.

Edited July 13, 2013 by SNOW_JOKE

[The PIT]

I think the blob shown on the radar to the ESE of me is a bit over optimistic. Ahh using the new scale which always makes things look too lively. Switched back to the old one and it's a weak echo to ese of me. Overall though convention declining here despite a peak of 29.1C not long ago.

[Supacell]

Shower now around Loughborough and a line developing from Sheffield towards Goole. I reckon if we take into consideration what Nick and John have said above we could be seeing some storms around the East Midlands, South Yorkshire and Lincolnshire soon.

 

And meanwhile the storms keep firing in North Yorkshire along the same line as has been there for the past couple of hours.

 

Edit: Rapid intensification of all those cells on last radar

Edited July 13, 2013 by Supacell

[pottyprof]

Rather heavy raindrops from the cell to my south.  Just on the edge of it and looks quite heavy over the Derbs/Notts border area.

Edited July 13, 2013 by pottyprof
Flippin keyboard..............

[ChezWeather]

Oh yes looking good for me, smack in the middle! 

[DAVID SNOW]

Well down saaaf Cumulus getting a bit taller now

[chrisb1357]

How's it looking for my area which is J28 M1, Alfreton.?

[jmatt]

Convection firing up nicely here and sky turning quite dark to the north

[ChezWeather]

Dark skies to my east, sun is still out here, temperature sitting at 27. 

[Thundery wintry showers]

The showers are fading as they pass over Sandhutton so this second one also lost its electrification by the time it got here, though there are still sferics showing to the west of here.

[johnholmes]

the current radar echoes over central northern England are running along the 700mb winds, from about 290, the 500mb winds are veered from that. What effect this will have on any storm direction is hard to tell until one actually is in the 18-24000ft height band but maybe they are already.

Tops as the Watnall acent suggested could go eventually to over 38,000ft.

best thing is watch the radar echoes and see what their direction is as time goes on.

Edited July 13, 2013 by johnholmes

[weatherobsuk]

Things start to be following along the lines of the GFS forecast, isolated cells to the East of the Pennines intensifying for a time as they head into the Peterborough area. Max daytime heating is beginning to ebb away as the sun lowers, unless nocturnal cooling somehow sets off one or two rogue mid-level storms as the CF moves into the Midlands.

[jmatt]

Clouds are shooting up just to the NW of me. Mesmerising seeing the clouds tops rise steadily as I watch