Thunderstorms and Amber Weather Warning in the Southwest

[Wilts Wanderer]

From 1600hrs today Network Rail has imposed a 50mph restriction on all routes between Swindon and Newton Abbot due to a severe weather warning (Amber) issued by the Met Office earlier today. A large proportion of intercity services have been cancelled preemptively and despite this the evening peak is being severely hampered by the slow running.

Whilst I support the idea of caution, as we've all seem what a tree strike can do, does 50mph seem a little over-cautious? It won't be dark until after 2100 and there hasn't actually been much rain yet, just a few heavy squalls.

 

[The Planner]

I suppose it is down to localised heavy rain, last weeks storms dumped a months rain in an hour in some places, so presumably if you come up to a bit of track with water above the ballast or sleeper at 100+ compared to 50?

 

[PHILIPE]

I suppose it is down to localised heavy rain, last weeks storms dumped a months rain in an hour in some places, so presumably if you come up to a bit of track with water above the ballast or sleeper at 100+ compared to 50?

GWR have also thinned out their service with every other South Wales service cancelled

 

[Wilts Wanderer]

I suppose it is down to localised heavy rain, last weeks storms dumped a months rain in an hour in some places, so presumably if you come up to a bit of track with water above the ballast or sleeper at 100+ compared to 50?

This is true, but 50mph seems overly disruptive. And how often does a train run into a few inches of floodwater and get anything but wet? Stop, report it, continue at caution etc. It's a bit post-Hatfield mindset; 'there might be a hidden broken rail, therefore all curves in Britain limited to 20mph.'

In some areas it isn' even close to raining, why a blanket restriction? Why not route by route - or has the closure of signal boxes mean the availability of data on local conditions has been lost?

 

[Phil G]

I was stood on Bath station waiting for my cancelled train in the bright sun! When a train finally arrived it was massively overcrowded and proceeded in sunshine until the other side of box tunnel where it got a bit gloomy until Chippenham. Massive overreaction I think.

 

[Spectre010]

It’s probably been imposed due to the risk of a train hitting a failed cutting slope or derailing due to an embankment failure affecting the track. NR have had a number of such incidents in the last few years and also some near misses due to convective storm type events.

 

[LAX54]

Looking at BBC reports of the weather in the West Country, think the Railway was more than justified !

 

[WelshBluebird]

Looking at BBC reports of the weather in the West Country, think the Railway was more than justified !

The underpass to get to the platforms at Didcot flooded too, so while it wouldn't have affected the railway operationally, just shows how bad it was in some places.

 

[LAX54]

Only needs heavy rain to run off fields, roads etc onto the railway and dislodge ballast in the process to stop traffic, if winds are high with trees in full leaf, have the chance to topple etc, where it might be nice and dry in one location, a mile down the road could be a vastly different story

 

[jimm]

And looks like water got into some bit of signalling kit between Oxford and Worcester, causing major delays yesterday evening, with the 18.22 from Paddington to Hereford not arriving until 00.48 today, a mere 196 minutes late.

Disruption is currently forecast to continue until 17.30, with some cancellations and delays to some services of up to 20 minutes.

 

[Wivenswold]

It's worth also noting that the data the Met Office were looking at would have indicated the potential of damaging winds associated with the downdrafts caused by the storms, one weather agency, Estofex, advised of a slight chance of small tornados embedded in the storms too. So the risks went beyond those relating to heavy rain.

 

[Wilts Wanderer]

Interesting 50:50 split of the vote. If you remove mine, it is 24 each way.

The weather was severe in localised places only. I live 18 miles from Bristol and we had about 20 mins of light rain around 10pm, and a clear sky at midnight. My issue is that imposing blanket limits in such a broad brush approach probably isn’t the best way to approach these things. Why can’t drivers report weather conditions?

 

[Spectre010]

Interesting 50:50 split of the vote. If you remove mine, it is 24 each way.

The weather was severe in localised places only. I live 18 miles from Bristol and we had about 20 mins of light rain around 10pm, and a clear sky at midnight. My issue is that imposing blanket limits in such a broad brush approach probably isn’t the best way to approach these things. Why can’t drivers report weather conditions?

The problem with Drivers reporting on the conditions is that it maybe too late to apply any effective control measures and that could well be the train hitting the obstruction. Generally blanket speeds are put in place a couple of hours before the forecast event to allow for the variability of the forecast and then not lifted until two hours after the forecasted end of the event (unless conditions are such that it needs to be extended or they can be ended early). The ORR take a dim view on trains running without mitigations measures in place when the chances of an earthwork failure are increased by heavy rainfall events.

 

[al78]

In some areas it isn' even close to raining, why a blanket restriction? Why not route by route - or has the closure of signal boxes mean the availability of data on local conditions has been lost?

Forecast models can predict that atmospheric conditions are favourable for thunderstorms and torrential downpours across a region, they cannot predict exactly where each individual thunderstorm will develop. Therefore, what happens in a case like this is that some areas under the warning get soaked and others get missed altogether, then wonder what the fuss was about. It comes down to the planners to decide whether the percentage chance of torrential rain and associated disruption is high enough to warrant pre-emptive action, but the warning will be county scale, so it is a case of apply restrictions across one or more counties, or take a chance you will be lucky.

 

[al78]

Interesting 50:50 split of the vote. If you remove mine, it is 24 each way.

The weather was severe in localised places only. I live 18 miles from Bristol and we had about 20 mins of light rain around 10pm, and a clear sky at midnight. My issue is that imposing blanket limits in such a broad brush approach probably isn’t the best way to approach these things. Why can’t drivers report weather conditions?

The problem with that is that when you have convective activity and associated severe weather, the situation is very dynamic. Thunderstorms can develop, mature, and decay within a couple of hours. If a driver reports that there is torrential rain in city A, by the time the report gets to someone who is able to take action based on it , the thunderstorm over city A might have dissipated, and new thunderstorms have developed and are now deluging cities B, C and D.

 

[Taunton]

The problem with Drivers reporting on the conditions is that it maybe too late to apply any effective control measures and that could well be the train hitting the obstruction. Generally blanket speeds are put in place a couple of hours before the forecast event to allow for the variability of the forecast and then not lifted until two hours after the forecasted end of the event (unless conditions are such that it needs to be extended or they can be ended early).

Meanwhile the aviation industry has managed with minute-by-minute weather measures as required, and has done so for generations. If you suggested the measures were arbitrarily set by someone in an office in Milton Keynes the day before, they would laugh in your face.

 

[Spectre010]

Meanwhile the aviation industry has managed with minute-by-minute weather measures as required, and has done so for generations. If you suggested the measures were arbitrarily set by someone in an office in Milton Keynes the day before, they would laugh in your face.

The decision regarding blanket speeds is made by the individual Routes based on the forecasted rainfall totals, saturation of the ground and trigger levels that have caused issues in the past, not by someone in head office in MK.

The aviation industry analogy isn't really applicable as planes can alter their flight path and carry weather “radar” equipment. This is all about rainfall falling unpredictably on Victorian designed infrastructure that hasn’t been maintained to an appropriate degree over the last 50 odd years that may fail in front of a train that can’t avoid the debris.

The level of granularity and accuracy for weather forecasting as well as the knowledge of the infrastructure required to allow an aviation type approach to be adopted just isn’t there yet.

 

[Jimini]

I was in Swindon overnight on Thursday and can confirm the weather from about 1900 through to 2100 or so was apocalyptic!

 

[Temple Meads]

Regardless of the rights or wrongs of blanket speed restrictions, it lowers the public perception of the industry even more when they are imposed while the weather is dry with the sun trying to come out, as was the case in Exeter (among other places I'm sure) on Thursday afternoon.

 

[FGW_DID]

Damned if they do & Damned if they don’t and then castigated for whatever decision by the ‘highly knowledgeable’ folk from the Department of Hindsight!

 

[LAX54]

Surely it is simplier and safer just to have a blanket ESR over the whole area ? When you start doing a bit here, a bit there, that's when mistakes can happen, and if the Met Office advised NR of severe weather affecting the whole area, as a member of the public I would expect the Company to take note ! But then most members of the public think if it's sunny here, then its sunny everywhere !

 

[Wilts Wanderer]

I was in Swindon overnight on Thursday and can confirm the weather from about 1900 through to 2100 or so was apocalyptic!

This sort of proves my point, the speed restrictions were applied at 1600hrs between Swindon and Newton Abbot and Reading to Taunton via Westbury, before it had even started raining in Bristol/ Weston where the forecast weather was expected to make landfall. Even if the imposition had been delayed until 1730, by which point it was starting to rain in those places, a large proportion of the peak service would have been saved.