Long range storm forecasting

[Coast]

Well I'll lick off the new area with this one:

What is the soonest you would start relying on data, models, websites etc to forecast a coming thunderstorm?

I notice the big hitters like Nick and Bricks NW Storm forecast, TORRO, ESTOFEX and UKASF all seem to come out in the 12 hours or so before hand and include references to the Skew T charts amongst others, but are the indications there in GFS charts etc some time before hand? What have you found to be the accuracy and when do you start to believe the data - when the lightning detectors start showing it?

[dogs32]

Going to be honest here How I think...so here goes.....

I have learnt alot over the last few yrs on watching these lightning detectors and have found only netwetaher one to be the most reliable out of them all..

And I think what Nick or Brick does is the safest way in general ...play it safe and wait!!!

While loads of other forecast take bigger gambles....The most I would say is Estofex

Edited August 27, 2008 by dogs42

[Jane Louise]

I admire Nick F and Brickfielders forecasts,they are always very accurate.I'd be lost without them lol

I also follow the storm risk and Estofex which I find quite good to.

Regarding the lightning detectors, I have found that not a lot of them are accurate.The one I always use to track the storms is the Netweather extra radar, now that is always spot on.

Torro is pretty good too.

Edited August 27, 2008 by Jane Louise

[Coast]

I have to admit that first thing in the morning, when I get to work I check Nick and Bricks NW Storm forecast, TORRO, ESTOFEX and UKASF all in that order.

The USAF 21st Operational Weather Squadron thunderstorm loop is a good general heads up, but not accurate enough to differentiate a hit/no hit area in the UK. I do occasionally look at GFS charts but not too far in advance. I think the information from posters here is the best start on the trail and then the masses of detectors, radar and webcams through the UK and surrounding countries (do I ever get any work done here????) I do love a 'virtual stormchase' almost as much as a real one!

I would also like to understand SkewT charts more and should take the time to sit down and read up on them.

Edited August 27, 2008 by Coast

[BrickFielder]

The best longer range indicators for me tend to be the 850-500hPa lapse rates and mixed layer cape charts along with netweather storm charts of course.

When the lapse rates are above 28C then providing the right forcing is present there is a risk of thunderstorms. Timings of events in relation to peak heating, residual cloud cover, and forcing mechanisms can all change up till very close to the time so pinpointing specific areas tends to be done very close to the event.

[stormchaser1]

Like i mentioned this morning , these storms which are currently showing on the charts for saturday and sunday , have been cropping up on the CAPE charts since august 15th

This is what i wrote on our forum

I posted this on august 15th at 2027hrs

REMEMBER THIS DATE , and remember where you heard it from

[ ALONG WAY OFF I KNOW ] but im going to be keeping a sharp eye on this one

AUGUST 28TH AND AUGUST 29TH

AREAS AFFECTED

EAST ANGLIA [] LINCOLNSIRE

Some very high cape values showing for that day 1600 to be exact, at this moment in time , these stoms could be severe

HOWEVER AND A BIG HOWEVER these will be downgraded between now and the actual date, but i will keep you all informed

===============================

OTHER AREAS AFFECTED

ISLE OF WIGHT / SOUTHAMPTON / AND UP TO STROUD

CAPE VALUES RANGING FROM 1400 FOR THE ISLE OF WIGHT DROPPING DOWN TO AROUND 600 FOR STROUD#

==========================

Again i will keep you all informed on a regular basis,

nigel

[Coast]

AUGUST 28TH AND AUGUST 29TH

AREAS AFFECTED

EAST ANGLIA LINCOLNSIRE

Some very high cape values showing for that day 1600 to be exact, at this moment in time , these storms could be severe

Well that's some of the most precise LRF storm casting I've seen!!!!!! A small wager then Nigel?

[stormchaser1]

I was using the NW Cape charts for this , and thats what they were showing at the time , ok a few days out , but for these storms to appear on and off the charts for some time I think the GFs has picked up on these quite well, im no expert,

forget it , sorry i posted

will keep my big gob shut in future

nigel

Edited August 27, 2008 by stormchaser1

[Coast]

forget it , sorry i posted

will keep my big gob shut in future

nigel

Oh no, I was quite serious about your LRF for storms this weekend. I can't even make my mind up a day in advance and this looks like you had good info sussed some time ago. I just wish I had the knowledge and understanding to go for the longer timescales, 12 hours is a long time for me

I wouldn't bet against it anyway, its looking closer by the day!

[stormchaser1]

Oh no, I was quite serious about your LRF for storms this weekend. I can't even make my mind up a day in advance and this looks like you had good info sussed some time ago. I just wish I had the knowledge and understanding to go for the longer timescales, 12 hours is a long time for me

I wouldn't bet against it anyway, its looking closer by the day!

no worries

nigel

[grab my graupel]

Oh no, I was quite serious about your LRF for storms this weekend. I can't even make my mind up a day in advance and this looks like you had good info sussed some time ago. I just wish I had the knowledge and understanding to go for the longer timescales, 12 hours is a long time for me

I wouldn't bet against it anyway, its looking closer by the day!

Just a slight misunderstanding is the way that I see it

Perhaps your use of the ' smiley' may have left your post a little open to misinterpretation .

Anyway please carry on guys....No harm done!

[Coast]

Perhaps your use of the ' smiley' may have left your post a little open to misinterpretation .

Smileys, I always blame the pesky smileys (they're like Gremlins!)

[grab my graupel]

Smileys, I always blame the pesky smileys (they're like Gremlins!)

Anyway, like you I will taking note of Nigels post, as my own longrange forecasting has been atrocious this year. I think I may have

to go back to the drawing board and try some different methods.

I'm lucky as I have done pretty well for storms this year though.

[dave48]

I quite like the GFS charts for long range forecasting, up to about five days, they don't often hit the nail on the head but they tend to give a good indication. With plumes for example they can get the position a bit wrong but they normally predict there will be a plume of some sort. I like having the 'heads up' so to speak. I have found though that really it is only on the night or morning before that the forecasts are really reliable, I always check the netweather ones and a variety of others around the internet.

Edited August 27, 2008 by dave48

[VillagePlank]

Ah well - think Birmingham, lunchtime, sunday perhaps another tornado.

(well it's far enough away for everyone to take it with a pinch of salt, huh?)

[dogs32]

whats everyones number one lightning detector....Mine is Netweather red Xs...Not a plug just the one I rely in real time

Edited August 27, 2008 by dogs42

[stormchaser1]

i mainly use strike display

nigel

[dave48]

I like netweather and UKMO ATD the best.

[Jane Louise]

Netweather extra radar is the one for me.Other lightning detectors I find are most unreliable.By just watching that red blob of heavy rain or a storm building up near my area on the radar is exciting and always very accurate.

[dave48]

Well I'll lick off the new area with this one:

What is the soonest you would start relying on data, models, websites etc to forecast a coming thunderstorm?

I notice the big hitters like Nick and Bricks NW Storm forecast, TORRO, ESTOFEX and UKASF all seem to come out in the 12 hours or so before hand and include references to the Skew T charts amongst others, but are the indications there in GFS charts etc some time before hand? What have you found to be the accuracy and when do you start to believe the data - when the lightning detectors start showing it?

Long range forecasting interests me a lot and from what I have seen there is a lot more progress to be made. I think convective forecasting is so difficullt as it is, even very close to a given event. I think it is widely regarded that there is so much research that need to be done in this area. I don't know of any person or organisation that can give reliable forecasts for thunderstorms for any more than a day or two ahead, it seems the quality of the data required just isn't there.

[dave48]

Using this week as a case study and leading on from what I said above is a good example of the current state of things. Almost every model and organisation has changed their view several times to the point that really a forecast can only be taken seriously on the day before the event at the earliest. This seems to be fairly typical of the overall situation. On the bright side, things can only get better and hopefully it won't be to long before storms can be accurately forecast a number of days ahead. Although sometimes I think the guessing game is part of the fun!

[Coast]

ESTOFEX have a whole load of information on the forecasting of severe convective storms here

And Netweathers, Nick F has a guide to UK storm set ups here

[johnholmes]

it will be a long time before accurate prediction of storms, their severity and where they are most likely, can be given more than 24 hours in advance. One can say fairly often it looks like a thundery set up at perhaps 72 hours, and a very broad idea of the most likely areas, but that is about all.

[dave48]

ESTOFEX have a whole load of information on the forecasting of severe convective storms here

And Netweathers, Nick F has a guide to UK storm set ups here

Thanks for posting those coast, Both great guides. I have already read the guide by nick f which I think is excellent but I hadn't seen that ESTOFEX article before, having a read through now!

Edited September 3, 2008 by dave48

[VillagePlank]

ESTOFEX have a whole load of information on the forecasting of severe convective storms here

That's probably about the best link I've *ever* seen on NetWeather. Nice one

Edited September 3, 2008 by VillagePlank