3rd Aug 2011 - Storm/convective Forecast Discusion And Reports

[Supercell]

Hi Will

You chasing today Mate ?? A little jaunt east for you and you should be in the sweet spot

Hey Paul,

I may do. I'll probably leave it quite late and decide then. Cambs is always a good spot, but i'd rather not push that far.

Still annoyed I missed the funnel Warwick/Leamington way the other week lol.

[Richie V]

Explosive growth on the south / west Yorks border now. Expect visuals on the radar in the next 45 mins!

Edited August 3, 2011 by Richie V

[Coast]

Watch how the areas of CAPE develop from mid afternoon:

[VillagePlank]

Watch how the areas of CAPE develop from mid afternoon:

Yes - still hope for clutching straws for Kent ... All the evidence is against it but, I don't know - I kinda think it might happen, even though my own forecast says virtually no chance.

[Stuart]

so near but to far for me to so no show :lol:

[TheToastPeople]

First clouds are starting to apear now, 45% humid and my station is saying 29.8c! and it really does feel that warm im toastin!

[Harry]

Yes - still hope for clutching straws for Kent ... All the evidence is against it but, I don't know - I kinda think it might happen, even though my own forecast says virtually no chance.

Well it's not overly clutching at straws IMO - the SE corner does appear to have a lot of the ingredients for storms to initiate...what is lacking is that all elusive trigger. The E/NE area of England have a lovely CZ forecast which is their trigger, which has prompted the various warnings.

The SE however, other than the heat alone being sufficient to initiate convection, does not have that luxury. Were some kind of sea breeze CZ/thames estuary CZ to develop then I suspect there'll be a bit of a boom. In the absence of that however, it does appear that we'll get faux Cb's like we had yesterday, rising up from the downs and raising false hopes...

Alas, we can hope, the gun is ready for firing. Just need that spark...

[Coast]

Here's a couple that I haven't quite worked out the significance of yet (if any!), but it's near the top of the scale at the time and places under consideration:

To help evaluate the degree to which the day's mixing is convectively driven, a thermal "hot air" parameter "B/S" represents the ratio between Buoyancy and Shear production of turbulence. A small B/S value indicates wind shear, due to wind changing with height, is likely a significant problem - at present the best guidance I have, based upon sailplane pilot reports, is that on days with B/S of 5 or less the thermals are likely to be too broken to be usable - hang gliders and paragliders, who are able to turn in smaller circles, seem to be able to thermal in smaller values, based on a few reports I have received. At a B/S of 10 or above, vertical shear is likely not a significant factor. Note that only a single value is provided, representing the BL as a whole, whereas B/S normally decreases closer to the surface.

For those interested in more scientific detail, the B/S ratio is not per se an empirical approach but is based upon the non-dimensional number used to distinguish between "buoyancy dominated" and "shear dominated" BLs (and those in between). It is the ratio of the "buoyant production of turbulent kinetic energy" to the "shear production of turbulent kinetic energy" with both being well defined terms. However, the cross-over criterion between "workable" and "unworkable" thermals must be determined empirically (and for that matter there is no sharp cut-off between the two cases).

Note: This parameter assumes that buoyancy results only from surface heating - if convective clouds are present additional buoyancy will be released aloft by condensation heating, increasing W* above that used for this calculation and thus increasing the actual B/S ratio above that predicted

http://www.drjack.info/BLIP/INFO/parameter_details.html#BS_Ratio

[loopydreamer]

Oh lucky you! I live just up the road in Chichester, I don't think we will see anything today which in some respects I am pleased about because this afternoon I am playing with Sussex Fire and Rescue and a 17meter carbon fibre pole!

You will be playin with a 17 meter carbon pole ????

[Katherine Birkett]

Any hope for south Lincs storm-wise?

[Paul Sherman]

TCU Being reported in Bucks at the moment and the slightest hints at a small CU Field near the Penines at present. Could have kick off between 2-3pm from that Convergence Zone which is starting to take shape on Sat24

Paul S

[peterf]

bubbling up from the west now.

[Static Prevails]

TCU Being reported in Bucks at the moment and the slightest hints at a small CU Field near the Penines at present. Could have kick off between 2-3pm from that Convergence Zone which is starting to take shape on Sat24

Paul S

Would that be moving south to north?

[Cheshire Freeze]

TCU Being reported in Bucks at the moment and the slightest hints at a small CU Field near the Penines at present. Could have kick off between 2-3pm from that Convergence Zone which is starting to take shape on Sat24

Paul S

Yeah can see that quite clearly on the sattelite imagery, seems to be curling down into the Midlands, not too far east of here too.

[Coast]

TCU Being reported in Bucks at the moment and the slightest hints at a small CU Field near the Penines at present.

Later:

East of England yellow warning:

Issued at - 03 Aug 2011, 10:50

Valid from - 03 Aug 2011, 15:00

Valid to - 03 Aug 2011, 22:00

Whilst many places will be dry, the public should be aware that isolated thunderstorms will develop this afternoon over parts of eastern England, bringing the potential for torrential downpours and localised flooding.

http://www.metoffice.gov.uk/weather/uk/ee/ee_forecast_warnings.html

Winslow Webcam:

http://www.wunderground.com/webcams/habile/1/show.html

[paul m]

Dont you just love nowcast when it works. According to them its quite cool here at 8 c

[Paul]

First interesting looking cell of the day has popped up between Manchester and Sheffield.

Very well modelled by the nmm too which had the initial cells in exactly that spot on both the 00z and 06z run..

[UKVoodoo]

Still in the club so thought i'd say hello to my fellow storm deprived souls

Edited August 3, 2011 by UKVoodoo

[Lauren]

I don't think I'll see anything today and that is based solely on gut feeling!

[Adi F]

You will be playin with a 17 meter carbon pole ????

If we see a storm I will try to get a photo of me trying to fish for lightning lol

Yeah the thought of a storm today did send a shiver down my spine, I am told it is safe to use during storms, time will tell!

[Joneseye]

Yeah can see that quite clearly on the sattelite imagery, seems to be curling down into the Midlands, not too far east of here too.

looks like a small cell has formed to the east of Manchester.

Looking north out of my window (towards Oxford) I can see some bubbling convection in the distance, but not a lot to the south.

Edited August 3, 2011 by Joneseye

[Static Prevails]

It seems like today might me more interesting for me than I thought. Some very encouraging posts in this thread.

[Staffordshire]

Can someone post a link to a good radar cause Im stuck with meto and I don't really like raintoday

[Supercell]

Early signs are good. Strong cumulus development here.

[Paul]

Can someone post a link to a good radar cause Im stuck with meto and I don't really like raintoday

http://www.netweather.tv/index.cgi?action=other;type=radar;sess=