"thundery Rain"

[maidstone weather]

For the actual answer to the question though, we would have to ask a BBC weather presenter, since it is them that use the term.

I have emailed two of my local presenters around 2pm, one of which was on TV today, but sadly they haven't replied yet! :lol:

[Harry]

I have documented pretty extensively my thoughts on what the definition SHOULD be lol.

However, what I feel I know to be true (i.e in my strong opinion lol) is that because forecasters cannot be sure if something will turn thundery (i.e contain thunder) they generalise by saying thundery. That way, if it produces no sferics, they can argue the rain was torrential or thunderstorm like, hence the forecast was accurate. If it does contain sferics then "wow" they were spot on. It is easier IMO to forecast torrential rain/v heavy rain, than it is to forecast thunder and lightning.

I can understand this to an extent, as you can get well defined Cb's which visually, should be electrical - OR, you can see on radar that something looks intense enough it SHOULD be electrical, but for some reason isn't. Similarly you can some p$$$ poor Cu roll over, and low and behold it is electrical.

I think forecasting thunder/storm events is very difficult, thus caution should be used in forecasts. Though I think the term thundery should mean A or B, not both. Similarly, I wouldn't expect a weather forecaster to say a particular storm was tornadic, when in fact it produced no funnels but was merely rotating - that is misleading and IMO inaccurate.

BBC forecasts are FOR the joe-public, not weather fans. Therefore, I don't expect weather forecasters to use specific/technical terms on a regular basis! Hence, why Michael Fish got hammered in the media by saying in 1987 a hurricane wasn't on the way - actually, he was spot on with his forecast and has been since - it was not a hurricane at all! But what is the point (as has been vehermently made in the last 22 years) in being technical when the general public do not understand? To the public, hurricane force winds is the optimum word here - they don't care if it is of tropical formation/tropical air, with defined eye wall and formed from a cluster of tropical thunderstorms...they want to know trees, tiles and chimneys are coming down! Call it tornado, hurricane, typhoon, storm whatever!

Similarly, many brontophobes/astraphobes/keraunophobes etc, DO care every much about the term thunder!!!! I am sure, when these people here the term 'thundery showers', 'thundery rain' and 'thunderstorms' on the forecast, they become anxious, nervous, panic stricken - all because some 'idiot' (harsh, but true IMO) wishes to be descriptive with his forecast, rather than get the point across...heavy, torrential rain does not cause brontophobes panic attacks, THUNDER DOES!!

Oh dear - off my trolley I go again...lol

But to summarise - I think in terms of the weather, it IS important the right message is got across. It should be IMO both accurate, but also clear. Thundery showers or rain, to describe torrential rain, and actually maintain that as a valid description as a forecaster is, IMO, ludicrous and a cop out. After suffering a pretty severe case of brontophobia throughout most of my youth (I suffered anxiety, panic attacks, hysterics etc), hearing 'thundery' in the forecast when I was younger created fear and I am sure, to some of the members on here, it does the same too!!

That's my concluding thoughts on the subject...LOL!

Edited August 24, 2009 by Harry

[Thundery wintry showers]

In my experience when forecasters say "thundery rain" they usually mean an area of large-scale rainfall (usually a frontal zone) with embedded thunder. I think the term is fine in itself but that they should take the time to express the probability of thunder occurring. The fact that they don't probably stems partly from BBC policy and partly from lack of time allocation for forecasts.

The tendency for "thundery rain" to be a damp squib for most shouldn't come as a surprise when you consider the mechanisms involved. It implies extensive cloud cover (or else there wouldn't be large scale areas of rain) and therefore no scope for strong surface heating from the sun, reducing the amount of impetus provided to rising convective cells.

If it was forecast to be an area of substantial thundery activity (e.g. a MCS, or an area of thundery showers that has merged into longer spells of rain) they would usually say "thunderstorms" not "thundery rain".

[chrisbell-nottheweatherman]

Well, speaking as an ex-brontophobe myself, I remember as a kid being worried if thundery rain was forecast. Anyhow, this discussion leads to another question - if thundery rain is rain of a type and intensity that often accompanies electrical activity, then what is the threshold value in mm per hour?

[Harry]

Well, speaking as an ex-brontophobe myself, I remember as a kid being worried if thundery rain was forecast. Anyhow, this discussion leads to another question - if thundery rain is rain of a type and intensity that often accompanies electrical activity, then what is the threshold value in mm per hour? :blink:

LOL you are taking the Michael now though fair point! It depends I would have thought on the scale various radars adopt - for example - on the NW Traditional radar, excess of 32mm/hr shows up as white, with a clear scale running down the page. I would say, based on THAT radar, that torrential (or for arguments sake, thundery style rain) would be something that would show up as white on the radar.

But I do not know the scales adopted on other radars, and as such scales used by other forecasting bodies. I would say 32mm upwards would be fair assessment of 'thundery rain' - but it's only a guess (if a definitive scale is even used)

[maidstone weather]

Well so far a reply from one of the two forecasters I emailed... introducing Nazaneen Ghaffar

Well Dan.....that is a very interesting discussion. I guess there is no right answer to that conundrum, but in my opinion thundery rain is heavy rain with the ocassional thunder and/or lightning. In my forecasts I would only use the term thundery rain if I thought there was also the possiblity or thunder and lightning. Otherwise I use the term 'heavy rain' - regardless if the intensity of the rain is the same as that during thundery conditions - why say thundery rain if there will be no thunder/lightning?!

But like I said, that is just my opinion. At least next time you hear me use the term 'thundery rain' you'll know there is probably thunder/lightning too!!!

Nazaneen

Edited August 25, 2009 by maidstone weather

[The watcher]

Thundery rain: Rain that has the downpour/torrential significance without the Thunder and Lightning. However a risk of Thunderstorms or Thunder and Lightning is possible.

You know it is possible to have towering CB's with very heavy rain but no Thunderstorm.

[Snowyowl9]

I`ve voted for other as thundery rain can just sometimes bring light rain with thunder quite frequent even no lightning but nothing loud,overhead or so far away that happened most often in the 1990`s(not showery as such) the 1980`s gave proper major thunderstorms and little or no thundery rain as I remember,this decade seems to be bringing back thunderstorms again,but nothing like the scale of the 80`s for severe.

[Terminal Moraine]

To me the term thundery rain means rain ranging from heavier than 'normal' heavy rain up to that of thunderstorm intensity, with or without any thunder heard.

I'm not sure if there's any official Met' Office definition of thundery rain, I'll look it up when I get home unless someone beats me to it.

[Thundery wintry showers]

I think the use of "thundery rain" to refer to rain of thunderstorm-like intensity is a poor usage and will serve to confuse the public. When your average man or woman on the street hears "thundery" it is obvously going to carry an association with thunderstorms. In that case the reference to thunder should be taken out and replaced with something to illustrate the intensity of the rain.

My interpretation of "thundery rain" was always along the lines of what the forecaster in the quote a few posts up said (basically an area of prolonged rain with probable embedded thunder/lightning). I think that is a legitimate usage of the phrase, though if used, it should be qualified IMO by adding some info on the probability of thunderstorms actually happening. It's one case when minimising the output of information in a forecast actually causes more confusion than it is supposed to solve.

[dogs32]

Well Im glad it's a tie break at present..

I am still going for with or without thunder as many BBC weather guy's use this expression

Edited September 27, 2009 by dogs32

[Snowyowl9]

http://dictionary.babylon.com/Thundery_rain

Just one brief definition link above.

When the BBC say thundery rain coming in then I will expect thunder possibly thunderstorms mixed in with torrential dowpour from mid-level cloud but it doesn`t always have to be heavy thats when the weather will just beat everyone.

I`ve never referred to thundery rain without thunder the same goes for Thundery showers.

If the forecast is just for heavy rain and no thunder then that`s all you`ll get,thunder will be a bonus.