Convective/Storm Discussion Thread 25/5/16 onwards

[Azazel]

probably not indicative of anything, but i have a massive headache this morning which often happens when there's a chance of thunder:D

[Ben Sainsbury]

Some Sunny Spells have now appeared to the SE of me, along with some Ac Cas around!

[A.J]

probably not indicative of anything, but i also have a massive headache this morning which often happens when there's a chance of thunder....

 

....on a completely separate note, my homebrew barley wine was sure damned tasty last night 

[Harry]

8 minutes ago, ajpoolshark said:

probably not indicative of anything, but i also have a massive headache this morning which often happens when there's a chance of thunder....

 

....on a completely separate note, my homebrew barley wine was sure damned tasty last night 

I have a bit of a headache and feel like I've had a mini-stroke....if that's not a precursor I don't know what is

[DAVID SNOW]

32 minutes ago, Harry said:

Where do people get the ECM precipation models?

NW, Meteociel, Wetterzentrale - can't find precip charts 

 

Try the Icelandic Met Office

[MattTarrant]

The ten commandments of weather:

Thou shall have a headache before the thunder

[Harry]

I find it interesting that Estofex have issued an MD in one of only a few areas of NW Europe not under at least a Lvl 1/50% lightning risk hatching.

The only reason I find this interesting is that not too far from our shores models are clearly struggling with the synoptics, which may also explain the sudden emergence of potential downpours across SE-UK early tomorrow (unless they're not recent developments and they hid there all along)

[Speedway Slider]

43 minutes ago, Azazel said:

probably not indicative of anything, but i have a massive headache this morning which often happens when there's a chance of thunder:D

Well, I always get a butterflyish feeling in my stomach when storms are a possibility, even if I have not seen a thundery forecast.... Having pangs this morning funnily enough.... Is there any science in the headachey/tummy churning symptoms pre thunderstorms??

[Nick F]

1 hour ago, Harry said:

Not sure whether it is an error in the model, but UKMO precipiation projections generate some intense downpours across the SE/Home Counties/Midlands between 04z and 07z tomorrow.

It doesn't appear to be supported however by any other model.

Interesting.

ECMWF indicates some heavy rain developing in the areas you mention early Sat morning,  EC showing fairly decent CAPE across the SE at 00z and 06z Sat as well, maybe the SE's only chance, as storm potential has a west bias otherwise!

 

[Mapantz]

The MetOffice have issued a yellow warning:

I too have a headache. I looked this up, and it says it is indicative of Newton Poppleford staying dry. :O

The sun is out here, temperature up to 18.5 °C 

[Chris K]

The good news is the Sun is now out in it's full glory here in Bristol. With a bit of luck that will help with surface heating later.

4 minutes ago, Speedway Slider said:

Well, I always get a butterflyish feeling in my stomach when storms are a possibility, even if I have not seen a thundery forecast.... Having pangs this morning funnily enough.... Is there any science in the headachey/tummy churning symptoms pre thunderstorms??

There have been brief studies, but conclusive and definitive evidence is hard to come by and I certainly couldn't state now whether it is true/not true. The general thoughts are that headaches may be caused by changes in factors such as barometric pressure, temperature, dew point, humidity, particularly if these changes are large and sudden. It also depends on a person's sensitivity to these changes.

No idea on stomach churns - that's more a physical reaction to what you are/are not eating/drinking, or nerves/anxiety etc.

 

[SteveB]

I have a feeling this is going the way of the pear for my neck of the woods.

 

Suspect the cloud cover will hang around to long for anything to develop. Were there are breaks further South & East I feel will be were storms will be.

Temp 15.7c

Humidity 78%

Dewpoint 11.0c

Edited May 27, 2016 by SteveB

[MP-R]

Cleared up quite nicely here in north Bristol and feeling warm with the temp on the rise. 

[Gordon Webb]

Weather warnings out for today and tomorrow and i appear to be just enough east to avoid them phew

 

[SteveB]

3 minutes ago, MP-R said:

Cleared up quite nicely here in north Bristol and feeling warm with the temp on the rise.

Still very cloudy in Nailsea

[timeless]

5 minutes ago, Gordon Webb said:

Weather warnings out for today and tomorrow and i appear to be just enough east to avoid them phew

 

wish l could have said the same LOL.

[A.J]

17 minutes ago, Mapantz said:

 

I too have a headache. I looked this up, and it says it is indicative of Newton Poppleford staying dry. :O

The sun is out here, temperature up to 18.5 °C 

I shouldn't laugh....but.............

 

anyhoos, just to wet the appetite for storm lovers everywhere, here's one of my favourite storm clips.....the end of the world is coming!

 

[MP-R]

7 minutes ago, SteveB said:

Still very cloudy in Nailsea

Give it time, looks like Nailsea is right on the edge of the overall cloud mass moving west.

[Ben Sainsbury]

Clear here, cloudier to the south, but lots of cumulus beginning to pop up now!

[Nick F]

Updated convective / storm forecast for today / overnight period:

Storm & Convective Forecast

Issued 2016-05-26 17:05:48

Valid: 26/05/2016 1800z to 27/05/2016 0600z

DAY 1 CONVECTIVE FORECAST - 27TH MAY 2016

Synopsis

Elongated upper low extends from west of Iberia NE toward the UK on Friday, with a weak cyclonic SWly upper flow across southern UK. Flow veers with height from E to NEly flow at the surface. Increasing instability/steeper lapse rates have moved N out of N France overnight, which will bring an increased risk of thunderstorms across parts of S England and S Wales today and perhaps into the overnight period.

DAY 1 CONVECTIVE FORECAST - Fri 27/05 06z to Sat 28/05 06z

... SW/S ENGLAND, MIDLANDS, WALES and EIRE ...

Scattered showers / isolated storms ongoing first thing in the morning across S/SW UK should ease and allow recovery of the atmosphere to allow sunny spells to develop. Plume of steeper mid-level lapse rates spreading north atop of increasingly moist boundary layer across southern Britain (w/ dew points reaching 12-14C) will create an increasingly unstable atmopshere by the afternoon in the above areas - with GFS indicating 300-800 j/kg CAPE. With weak flow aloft and lack of upper forcing, wind convergence will be the main forcing mechanism for heavy showers and thunderstorms to develop in the above areas. Despite environment of weak vertical shear of 10-30 knts, clouds may attain enough height to bring a MARGINAL risk of isolated large hail, also slow storm motion will bring a risk of large rainfall totalls over a small area leading to a risk of localised flooding - the marginal risk most likely SW England/Wales. Weak winds aloft and surface convergence will also be ideal conditions for a few funnels or even brief/weak tornadoes to form with stronger updrafts.

Then overnight into Saturday morning, showers and a few storms may continue across Wales, SW England and EIRE before slowly easing. Further east, a few models, more particularly ECMWF, develop an area of heavy thundery rain across parts of Midlands and SE England by 06z Sat, probably due to approach of the left exit region of mid-upper jet streak over N France and some surface wind convegence which will combine to increase forcing for ascent. ECMWF shows some modest CAPE values across the SE, so embbeded thunderstorms are possible - bringing a risk of hail, localised flooding and gusty winds. May upgrade to MARGINAL over this area if stronger storms develop.

 

Issued by: Nick Finnis

[William Grimsley]

Ok, so I've got a decision to make here. I'm going to chase but not sure which direction, the Met Office seems to break thunderstorms out NW of Dartmoor which is within driving distace just about, or another possibility is going NE towards Somerset. What do people think will be the best direction to go?

[Ben Sainsbury]

5 minutes ago, William Grimsley said:

Ok, so I've got a decision to make here. I'm going to chase but not sure which direction, the Met Office seems to break thunderstorms out NW of Dartmoor which is within driving distace just about, or another possibility is going NE towards Somerset. What do people think will be the best direction to go?

A few showers in the Bristol Channel right now, my bet would be heading NE too, as highest instability seems to be there, along with the clearest skies so far. It's hard to call until it's happening of course.

Good Start to the day if I must say so!

Edited May 27, 2016 by Ben Sainsbury

[MattTarrant]

I think the earliest developments will be across South Wales, suggested by the weather radar anyway.

[A.J]

10 minutes ago, William Grimsley said:

Ok, so I've got a decision to make here. I'm going to chase but not sure which direction, the Met Office seems to break thunderstorms out NW of Dartmoor which is within driving distace just about, or another possibility is going NE towards Somerset. What do people think will be the best direction to go?

it might be an idea to base yourself at Tiverton. This'll give you the option of the A361 to north devon if anything develops there, whilst still having easy access to Somerset/BANES via the M5

[Carl46Wrexham]

52 minutes ago, ajpoolshark said:

I shouldn't laugh....but.............

 

anyhoos, just to wet the appetite for storm lovers everywhere, here's one of my favourite storm clips.....the end of the world is coming!

 

Now that is a storm. What we get is the equivalent of pulling out a pen knife on Crocodile Dundee. This storm is him pulling his machete out (fnarr fnarr) and saying "that's a knife"