471 replies to this topic

[Staffordshire]

I think the SW may be the sweet spot tommorow, personally not holding out any hope because of the shear amoun of times I've been let down. However I think some people could get some fairly heavy showers.

[Miguel Hugo Roberto]

Staffordshire, on 06 August 2011 - 20:03 , said:

I think the SW may be the sweet spot tommorow, personally not holding out any hope because of the shear amoun of times I've been let down. However I think some people could get some fairly heavy showers.

The southwest becomes more favourable in this sort of setup the later in the summer you get, especially in September/early October as the sea has warmed up a bit.

I'm hoping for something as the last thunder'storm' as opposed to shower was May 6th - when I was in the parched southeast.

[ajpoolshark]

Just a quick re-post of my thoughts for the midlands convective forecast for tomorrow.....


In reply to an earlier post...

"The FAX goes with the NMM and shows a trough moving into the SW tomorrow focusing showery activity in that area, the FAX though does show an Occlusion straddling through the midlands, meaning plenty of cloud cover, I reckon it's this occlusion that's making the NMM & GFS shy away from marked convection in our area as if cloudy, it will inhibit convection...Apart from that, as you say, the parameters are pretty good, plenty of convective energy & lift, a cold pool of air pushing in from the west steepening lapse rates...Still, will be watching the skies/radar with interest tomorrow afternoon"

[Nick F]

Convective / Storm forecast - Issued 06/08/2011 23:00



Valid: 07/08/2011 06:00 - 08/08/2011 06:00
Headline: ...THERE IS A RISK OF THUNDERSTORMS FORECAST...

Synopsis
Upper low extends across E Atlantic and the British Isles with a shortwave trough and attendant surface low to the west of Ireland Saturday evening moving east overnight into Sunday morning, to be centred south of Ireland at 12z and as an open wave across southern England by 00z Monday. Meanwhile, low near NE England Sat evening will deepen and move slowly north over the N Sea, with associated slow-moving occlusion bringing persistent heavy rain to parts of Scotland

... ENGLAND, WALES and IRELAND...

Short-wave trough over the Atlantic moving east towards the SW approaches by Sunday afternoon will steepen lapse rates across Sern UK and Ireland as colder air is introduced aloft. Ascent ahead of this approaching upper trough and attendant surface low from the west will likely lead to scattered heavy showers and thunderstorms moving in from west across Ireland then Wales and SW England intially by early afternoon, then becoming more widespread further E across central, southern and eastern England by evening.

Although vertical shear will be fairly weak where greatest instability is likely, fairly strong mid-upper SWerly flow across Sern UK suggests possible organisation of storms into clusters or line segments with a threat of gusty winds, hail, torrential rain and cg lightning. Also, where surface winds back ahead of approaching surface low from the W, sufficient low-level shear may combine with the low LCLs and low-level instability to produce an isolated weak tornado - more especially across S England. Though for now, do not expect an organised risk of severe weather - given weak vertical shear, and lack of any particularly warm and moist air in place. With the steep lapse rates aloft, storms may continue into the night for a time across southern counties.

Issued by: Nick F - Forecaster for Netweather

[Chris K]

Looks like it will be an interesting day but one of those days of watching the radar to see where things develop. Good luck for tomorrow Im hoping to finally catch something...

[TomW]

Bugganuts, on 06 August 2011 - 22:37 , said:

Looks like it will be an interesting day but one of those days of watching the radar to see where things develop. Good luck for tomorrow Im hoping to finally catch something...

Did you see the lightning at about 10:45pm.

[DeepSnow]

Looks good for us in south wales and the south west, hope that we actually get something tomorrow!

[Chris K]

TomWlx, on 06 August 2011 - 22:40 , said:

Did you see the lightning at about 10:45pm.

I was in the pub and didnt unfortunately. We had a torrential downpour, and another has just started now, but so far I havent heard any thunder or seen lightning.

[TomW]

Bugganuts, on 06 August 2011 - 22:42 , said:

I was in the pub and didnt unfortunately. We had a torrential downpour, and another has just started now, but so far I havent heard any thunder or seen lightning.

I was driving and saw a few flashes of lightning then heard some thunder but it soon died off.

[Chris K]

There seems to be showers intensifying in the Bristol Channel right now. Its actually looking promising from quite early in the day tomorrow. I dont want to jinx it tho..haha.

[Miguel Hugo Roberto]

Think I just heard some very distant thunder somewhere to my northwest. Had a very brief heavy downpour, must have clipped one of the Bristol Channel ones. I remain sat here with the window open listening.

[Nick F]

Michael Prys-Roberts, on 06 August 2011 - 22:55 , said:

Think I just heard some very distant thunder somewhere to my northwest. Had a very brief heavy downpour, must have clipped one of the Bristol Channel ones. I remain sat here with the window open listening.

Recent sferic plot on Atd over Bristol Channel/S Wales coast - so certainly a storm not far away.

[Chris K]

Theres a small cluster thats merged together scooting along the South Wales coast, intensifying heading in a line towards Cardiff then could hit Bristol. It might just miss me as im about 10 miles north of Bristol but if it keeps merging/growing could be a heavy downpour!

[Mesocyclonic]

UKASF have gone with a moderate risk for much of southern England and Eire for Sunday (map of areas affected at http://www.ukasf.co....rm-forecasts/64):

Areas Affected:

Southern Britain and southern Ireland.


Synopsis:

A complex, multi-centred area of low pressure will be present across much of Britain allowing for large scale ascent and unsettled conditions. An occluded front across northern Britain will be the focal point for a large area of heavy rain which may produce some localised flooding, but no lighting / deep convection is expected with this. However, the warmer, more unstable air further south will have the potential to produce thunderstorms.

Discussion:

Low pressure as stated in the synoptic discussion will allow for unsettled conditons and suffient SBCAPE values of 500-700j/kg are possible in the moderate zone during the afternoon. ELTs in the range of -40C indicate suffiently deep enough convection for plenty of lightning and also, the risk of moderate hail. Both LLS and DLS values are relatively weak, so sustained updrafts won't be likely, meaning storms will be of the pulse variety, but could produce some brief gusty winds. Funnels are also unlikely except for near topographcially (Wicklow Mountains) or coastline enhanced (south coast of England) boundaries.

Edited by simonskee, 06 August 2011 - 23:34 .

[Raidan]

The rain passing over my part of Bristol is not electrical,Had a downpour about a hour ago and that was it,lights flickered a few times which made me think something was near but nothing came of it.

[Raidan]

Just to add im getting frequent short showers only lasting seconds.

[ElectricSnowStorm]

A day of Thunderstorms and hail with flooding possible

see Netweather storm forecast for details about the storms

-

an earlier radar image showing the heavy rains or torrential rains over Northern areas with heavy downpours in other areas showing up especially in the SW. radar is for 5.30am.



-surface temperatures-1500hrs NAE 000z
GFS 00z latest run.
-upper temps at 500hpa - 1200hrs

-upper temps at 500hpa - 1800hrs

-CAPE 1500hrs

CAPE 1800hrs

-Lifted index 1200hrs

Lifted index 1800hrs
-

A very high risk of Thunderstorms today and this evening-lasting into late evening and maybe rumbling on into early hours.(in the storm risk areas)

Edited by ElectricSnowStorm, 07 August 2011 - 05:59 .

[Surrey]

wow! The day I pick to go out and we could get T-storms..And knowing my luck it will left trouser leg down!!! I know it -.- Oh well would be good to see something XD

[Stuart]

Good Luck all for today i Missed out on sat Afternoon there all die out before it get in to the area

[Surrey]

http://www.metcheck..../stormwatch.asp

Dosnt look that good 0.o