General Storm Discussion Thread

[johnholmes]

I never though about that before, but now you've said it, i realize thats exactly what seems to be happening! Like yesterday, for days it was giving like 50-60% chance of storms, on the day down to 30% with like 100 for cape and no lift! Tomorrow will most likely be the same!

Well not sure about storms today for here, or tomorrow, will have to wait and see! had some sun thismorning, and now a mix of sun and cloud, dont expect anything tho anymore!

exotic names like CAPE etc are simply derived from the basic skew-t outputs. The models are notoriously fickle when dealing with any form of precip, especially beyond about T+24-36, so it should be no surprise that the instability terms are equally as fickle.

[Crimson_Sprite]

You reckon John? As Pat stated earlier, in US, the CAPE and lift seem to be consistent days out and only seem to tend to get stronger on the day as oppossed to vanish. I mean a downgrade is one thing, and if the models are saying 200 CAPE or so for the past 8-12 runs, and then on the day when the "storms" are suppossed to be in favour for developement, if the CAPE was downgraded to 100-150, I could understand, but to have virtually nothing, almost everytime (it seems) is unreal. The GFS for instance has been giving me a great storm potential for tomorrow with 600-800 CAPE and -2 to -3 lift for tomorrow. This has been consistant now for like 4 days or so (this also happened for yesterday btw) and I will burst out with insane laughter if when I put my computer on tomorrow at 8.30am, and see no CAPE or lift, I think Im gonna loose it. I'll bet France and Germany dont have to deal with that on their models? :wacko:

Edited July 21, 2010 by Crimson_Sprite

[Nick F]

You reckon John? As Pat stated earlier, in US, the CAPE and lift seem to be consistent days out and only seem to tend to get stronger on the day as oppossed to vanish.

I agree with John, modelling of CAPE can be very fickle for the UK. I must add that numerical modelling of the atmosphere over the large interior landmasses of central USA, where CAPE predictions are seemingly more ‘stable’, is born by the fact that there is less martime interaction in the interiors and so modelling things like CAPE can be more accurate. Unlike across the UK where moisture, temperature and lapse rates, which CAPE is mainly derived, can fluctuate more on an small island surrounded by sea and affected by cloud more off the sea compared with over 100s of square miles of land. So that is why I think GFS seems to struggle modelling CAPE and precipitation.

[Crimson_Sprite]

ahh right, that totally makes sense.... I hate living on an island

[DeepSnow]

Ok i understand now Still dont make it any less annoying tho lol Im not so happy that i haven't seen lightning or thunder since end of june, beginning of july last year. Will have to hope something will happen some time this month or next month!

Edited July 21, 2010 by Deepsnow

[The PIT]

One of the reasons why I say wait for the evening before the day in question as things change fairly rapidly. It's also worth checking throughout the day as things sometimes (although others disagree) don't always go to plan.

Edited July 21, 2010 by The PIT

[Lynxus]

Theres a lot of convestion about in the SW at the moment.

Will be interesting in a few hours.

May get some heavy showers, maybe a clap of thunder.

[dogs32]

thought that was a real good answer Nick....Unlike across the UK where moisture, temperature and lapse rates, which CAPE is mainly derived, can fluctuate more on an small island surrounded by sea and affected by cloud more off the sea compared with over 100s of square miles of land

I was wondering the same a s Crimson...

But youve answerd my Thoughts of recent times

Edited July 21, 2010 by Pat Carter

[sbiggs]

Carrying on the discussion of the amazing disappearing CAPE and lift, the trend I've seen the past few days, is when I wake in the morning, Thurs shows a CAPE of between 700-1100 J/kg and lift of -4 for my area, and torrential rain forecast. By the time the afternoon models are run, Thursday has 0 CAPE and 9 lift, and Friday shows about 500 j/kg and -2 lift, whereas the morning showed nothing for friday.

This situation has been the same for three days on the trot now, showing end of week storms swapping and changing between tomorrow and friday. It can't make up its mind, I've never known such an unpredictable and poor storm season as this year. I'm still hopeful to have just 1 storm. I'd say the season is just past half way through... so frustrating though!

[Paul Sherman]

I reckon the Storms are waiting until the 14th August for the Evesham / Worcester area

[Coast]

It can't make up its mind

I suspect the weather knows what it's doing, it's the forecasts that are uncertain!

Always difficult to predict Tstorms and even more so exactly where and when. I'd stick with stuff from Nick F or Brickfielder, closer to the time for a more accurate analysis

[dogs32]

Ironically I wonder if its easier to predict Supercells and TS over in the States than this fluctuating Island for Storms due to the sea

by Nick's answer I would say yes...

Tornados a different ball game I reckon...which Supercell will drop one is a chasers skill and experience

Edited July 21, 2010 by Pat Carter

[RichardR]

Well this is a load of rubbish, BBC/metoffice making no mention of storms today and just "the odd shower", meanwhile tomorrow's CAPE has been reduced to very little here and many other places with a lifted index at a convection inhibiting 0 - 1. What bull! I hate living here too.

[Crimson_Sprite]

I totally agree sbiggs! If there was an ever more appropriate time to use the phrase STORM CHASER. I have been chasing the storm potential for a couple weeks now, as the "storm potential" days seem to keep getting knocked back a day and a day. The downgrade for tomorrow has already begun for me, with the 06z saying -1 lift (instead of -2 and -3) and CAPE is 500-300 from being 800-600. Still though, I am very happy with those figures!!! But we shall see run to run, if Thursday is going to be an utter dissapointment...

Here's one for you John--- understanding the volatility of the weather around islands causing it difficult to pin down accurate CAPE forcasts, why is it always a downgrade?????????????? Why not an upgrade???? Like "oooh I have 300 CAPE tomorrow in my area," but when turning on the computer 12 hrs and 2 runs later I check the CAPE situation again to have a stormgasm with looking at CAPES sky rocket to 1000 or something. Why does it never go up on the day and it always goes down?

[dogs32]

good post by Paul.S yesterday explaining the lack of Storms here compared to the 70's and 80's(Spanish bay of Biscay Plume)

makes alot of sense..check it out...yesterdays thread

all to do with negative and postive troughs from the South/West

I shall go away quietly...enough said by me...heading for the garden

Edited July 21, 2010 by Pat Carter

[johnholmes]

I agree with John, modelling of CAPE can be very fickle for the UK. I must add that numerical modelling of the atmosphere over the large interior landmasses of central USA, where CAPE predictions are seemingly more ‘stable’, is born by the fact that there is less martime interaction in the interiors and so modelling things like CAPE can be more accurate. Unlike across the UK where moisture, temperature and lapse rates, which CAPE is mainly derived, can fluctuate more on an small island surrounded by sea and affected by cloud more off the sea compared with over 100s of square miles of land. So that is why I think GFS seems to struggle modelling CAPE and precipitation.

fully agree with that Nick-had typed up much the same in answer to why the differences states to here or inland Europe.

[staplehurst]

We've had a couple of showers, mostly light, this morning from what appears to be a variant of altocumulus - most odd considering it's height and thickness, didn't realise it could produce a shower.

[Crimson_Sprite]

good post by Paul.S yesterday explaining the lack of Storms here compared to the 70's and 80's(Spanish bay of Biscay Plume)

makes alot of sense..check it out...yesterdays thread

all to do with negative and postive troughs from the South/West

I shall go away quietly...enough said by me...heading for the garden

Excellent- just found it and read it . Doesnt help with my bitter dissappointment though hahahahaha!!! I need to become a Weather Goddess and command the weather. I love severe weather. (must be the Yank blood in me) Give supercells, give me hurricanes, give me distant tornadoes that arent coming towards my house, and give me SNOOOOOOOWWWWWWWW (and none of this poxy 1cm stuff neither! )

I sure hope Mother Nature stops favouring those Europeans (we need an emoticion that has a violently shaking-fist-in-air-motion) and blesses us wit some insane weather!!

Edited July 21, 2010 by Crimson_Sprite

[SteveB]

A lovely light shower passing through, ahhh isn't that nice...... not.

[Neilsouth]

Some showers coming out of france towards south east , at the moment just weak..... Come on

[staplehurst]

Some showers coming out of france towards south east , at the moment just weak..... Come on

Yeah I was just watching those and trying to work out the track - looks like I am likely to be on the extreme western flank, so another central and east Kent jobby (and south and east East Sussex)

[Harry]

MetO suggest "odd sharp shower" with greatest risk over Kent...not looking too interesting at the moment though signs of slight intensification in the last half hour, from drizzle to heavier drizzle

[Crimson_Sprite]

hahaha, this is what we're reduced to... reporting different degrees of drizzle... and praying to random light 0.00005mm rain showers to intensify. Deary me- at least its warm out

I must say that since the sun is out the last hour, my cumulus clouds have gone from stomped-on cotton buds, to pastry puffs. Come on convection you can do it!!!! (insert-shaking-fist-violently-in-the-air-emoticon)

Edited July 21, 2010 by Crimson_Sprite

[DeepSnow]

Dark stormy looking clouds to my south/south east, will miss me to the east tho! I sware we have a storm shield over us!!!

[we1330]

  hahaha, this is what we're reduced to... reporting different degrees of drizzle... and praying to random light 0.00005mm rain showers to intensify.   Deary me-  at least its warm out   

I must say that since the sun is out the last hour, my cumulus clouds have gone from stomped-on cotton buds, to pastry puffs.  Come on convection you can do it!!!!  (insert-shaking-fist-violently-in-the-air-emoticon)

Lol!