MET OFFICE - Pessimistic Forcasts
Joined: Jun 2003
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From: EuroGA.org
What you could do, Bose X, which would be really useful is to get the UKMO to give access to their 3D model.
Currently, people have to use the U.S. GFS model, via one of many websites such as this one, or Meteoblue for cloud tops etc (which is GFS with additional processing) but the UKMO model is probably the best for this part of the world.
Currently, the only thing which UKMO offers (openly to noncommercial customers) beyond ~ 24hrs are the MSLP charts, and these don't tell you a whole lot.
Currently, people have to use the U.S. GFS model, via one of many websites such as this one, or Meteoblue for cloud tops etc (which is GFS with additional processing) but the UKMO model is probably the best for this part of the world.
Currently, the only thing which UKMO offers (openly to noncommercial customers) beyond ~ 24hrs are the MSLP charts, and these don't tell you a whole lot.
Joined: Jun 2006
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From: Maders UK
Met accuracy
Having visited the Metoffice 6 weeks ago to do the Met for Aviators Course I have to say I was impressed by the level of experience of the forecasters and the additional human input which moderates the forecast produced by their supercomputer.
Certainly comparing their forecast to the weather I experience most days (I fly most days) my experience is that they are pretty darned accurate.
I doubt that the forecasting inaccuracies which enabled Michael Fish to get it all so wrong a couple of decades ago will ever occur in the future.
I don't think there is any arse covering going on there, what I saw was a lot of motivated people who are passionate about the weather doing the best they can to prevent us from killing ourselves.
SB
Certainly comparing their forecast to the weather I experience most days (I fly most days) my experience is that they are pretty darned accurate.
I doubt that the forecasting inaccuracies which enabled Michael Fish to get it all so wrong a couple of decades ago will ever occur in the future.
I don't think there is any arse covering going on there, what I saw was a lot of motivated people who are passionate about the weather doing the best they can to prevent us from killing ourselves.
SB
Joined: Aug 2007
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From: 18nm NE grice 28ft up
Accuracy targets
I remember some time ago being told by a forecaster about being set targets for accuracy of general forecasting. It was considered acceptable to predict an event, for example a band of rain, to be correct within four hours in a 24 hour forecast. This could result in a forecast of dry morning and wet afternoon being completely the opposite but still met the target.
Joined: Mar 2008
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From: Inside CAS
This is not a claim to fame, but I personally know one of the BBC TV Met Office presenters, and recall her telling me how seriously they take the aviation forecasts and how responsible they feel for "the lives of pilots up there actually feeling the weather".
However, saying that, one of the reasons I have all but given up club rental (and pursuing group flying) is due to "ops managers/duty instructors" decreeing that all flying is off because there is a PROB 30 TEMPO out for gusts later in the day. At another club I used to hire from, the CFI would interpret the TAFs before first flight - depart for a jolly to France or whereever, and no-one else dare changing the flying state without his authorisation. Same net effect.
So, my point is that TAFS are too often regarded as the best, and sole, way of making a call on the day's weather. The apparent incision they display (e.g forecasting showers within a specific period) often seems to lead to too much trust being placed in them and the removal of human commonsense and pilot judgement out of the decision making process.
Joined: Oct 2004
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From: Hunched over a keyboard
Having been the victim of an optimistic set of forecasts (that left me half way across the Atlantic with 140 passengers and NO legal airport within range) I have to say that I would prefer a pessimistic forecast anyday.
The forecasts on the day in question gave every airport in eastern Canada and new England as useable for cat 1 ILS - but 45 mins past the PNR (Point of No Return) they were wiped out by blizzards. We ended up in goose Bay with an RVR of 300m (minimu Cat1 ILS 550m). That made for an interesting few hours and left us cursing the weather forecasters.
Pessimistic is fine by me - I'd rather be pleasantly surprised than unpleasantly surprised!
The forecasts on the day in question gave every airport in eastern Canada and new England as useable for cat 1 ILS - but 45 mins past the PNR (Point of No Return) they were wiped out by blizzards. We ended up in goose Bay with an RVR of 300m (minimu Cat1 ILS 550m). That made for an interesting few hours and left us cursing the weather forecasters.
Pessimistic is fine by me - I'd rather be pleasantly surprised than unpleasantly surprised!
Joined: Oct 2007
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From: Elstree
This is not a claim to fame, but I personally know one of the BBC TV Met Office presenters, and recall her telling me how seriously they take the aviation forecasts and how responsible they feel for "the lives of pilots up there actually feeling the weather".
eg in wind strength, speeds of movement of weather changes, risk of rain etc etc
A friend who flies 2 miles from the Met Office HQ often says that perhaps they should look out of the window from time to time.
I would really like the Met Office, and BBC forecasters, to produce a debrief on the day's weather. Why, for instance, a front scheduled to arrive at 13.00hrs slowed so much that it passed through at 03.00 the next day.
As an aside, are there questions asked at the MO on a daily basis as to how the TAFs and other outputs compared with the actuals?
Joined: Dec 2006
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From: .
In general I think the Met Office do a very good job. As someone has already stated I think that it is better to err on the side of caution when there is uncertainty regarding Wx. I like the layout of the Met Office website and find it very helpful. I can't help but think some of the criticism here is a little harsh.
Joined: Oct 2004
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From: Hunched over a keyboard
Anyone who relies solely upon forecasts is only going to have half of the information. Getting actual met (METAR, ATIS) fills in the gaps.
So, whilst the forecast may be pessimistic, if you turn up at your club/FTO and check the actuals you may well find that the day is better than you expected and you are in for a pleasant surprise.
So, whilst the forecast may be pessimistic, if you turn up at your club/FTO and check the actuals you may well find that the day is better than you expected and you are in for a pleasant surprise.
Joined: Feb 2003
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From: Oxford
This morning I was cursing the Met Office for an apparently pessimistic forecast. (And also the Benson met man, as he was the one forecasting TEMPO drizzle and 1000ft cloudbase.) As I flew back from Rochester after lunch I thought, 'Silly man - look, the cloudbase is at least 2500ft [couldn't go up to look due to CAS'] and the viz is great!' - indeed I said as much to my passenger.
Then I called up Benson and asked for an ILS for currency reasons and was surprised to be given it without any trouble. Then the Benson controller said 'For your information, the police helicopter has just reported 300ft cloudbase.' Gulp.
In the event the cloudbase was 800ft, in light drizzle, exceedingly close to the forecast TEMPO conditions.
So I think I take it back!
Tim
Then I called up Benson and asked for an ILS for currency reasons and was surprised to be given it without any trouble. Then the Benson controller said 'For your information, the police helicopter has just reported 300ft cloudbase.' Gulp.
In the event the cloudbase was 800ft, in light drizzle, exceedingly close to the forecast TEMPO conditions.
So I think I take it back!
Tim
Joined: Aug 2003
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From: Not a million miles from EGTF
Tim
Up to a point you are right.
When I go flying I have a range of trips I can do from staying in the local area, to flying to my local £100 burger establishment to making a more distant trip to relatives.
All of these can be achieved on many UK days. I use the wx to plan a flight (and return), but have often found that the pessimistic nature of many of the forecasts lead me to under-spec the day's outing
I have also found that there are occasions where significant weather events were not forecast, but have appeared after I was in the air, and then were entered on the updates.
I am a bit of a weather 'nut' and getting irritated at the way that the forecasts just don't seem to bear any semblance to the actuals. The TAFs and METARS for the reported TAF period could be for different airfields.
I have great respect for the Met Office staff and their professionalism, but from time to time I'd like them to look out the window.
Up to a point you are right.
When I go flying I have a range of trips I can do from staying in the local area, to flying to my local £100 burger establishment to making a more distant trip to relatives.
All of these can be achieved on many UK days. I use the wx to plan a flight (and return), but have often found that the pessimistic nature of many of the forecasts lead me to under-spec the day's outing
I have also found that there are occasions where significant weather events were not forecast, but have appeared after I was in the air, and then were entered on the updates.
I am a bit of a weather 'nut' and getting irritated at the way that the forecasts just don't seem to bear any semblance to the actuals. The TAFs and METARS for the reported TAF period could be for different airfields.
I have great respect for the Met Office staff and their professionalism, but from time to time I'd like them to look out the window.
Joined: Aug 2000
Posts: 1,856
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From: uk
I don't know about pessimistic forecasts but today, at 0926, the general forecast for Yeovilton is for "Very Good Visibilty". The METAR at 1200 is giving 6 km HZ, which is better than its been all morning.
At the same time Bristol was forecast to be "Good". At 1200 they are giving a RVR of 1500 metres.
Having relied on forecasts for weather critical activities for forty years I have less confidence in the Met Office than ever.
Yesterday the WNW wind forecast turned out to be NE at Compton Abbas.
At the same time Bristol was forecast to be "Good". At 1200 they are giving a RVR of 1500 metres.
Having relied on forecasts for weather critical activities for forty years I have less confidence in the Met Office than ever.
Yesterday the WNW wind forecast turned out to be NE at Compton Abbas.
Joined: Jan 2001
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From: In my own little world
Pessimistic is fine by me - I'd rather be pleasantly surprised than unpleasantly surprised!
Lead to some scud running back round to land again and almost an underpants change too. We were even more fortunate when we later saw what numerous obstacles had been in our path once the vis had actually improved !!.
Thank goodness for GPS and QDM from ATC (and sheer luck) that we didn't become another statistic that would have given the NIMBY's even more to moan about - I learned about flying from that !!.
Joined: Jun 2006
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From: Maders UK
met forecast
Last week I had a timely reminder of the effect of freezing precip on aircraft performance when I got pretty badly iced up at FL060 West of Birmingham after finding an ISOL EMBD CB with freezing rain while crossing a (non-forecast) murky occlusion - within 20s I had 2cm ice on the wing leading edge and a frozed windscreen. The TKS struggled to shed it and I finally lost all the ice when I landed at Humberside - it truly was a timely reminder.
I should have flown from Plymouth to Cumbernauld today but scratched the flight even though I hold a current IR and fly a nearly new known-ice approved aircraft (I filled up the TKS tank to capacity last night in preparation).
Looking out of my window here in Cornwall it's pretty frustrating because the conditions here are perfect for flying but I know that heading North over Wales things would deteriorate pretty quickly and with a freezing level around 500-1000ft around the trough that's heading Southwards any "sleet" (freezing rain) precip would stick to my airframe like glue - even with the TKS on "max" setting (which gives me 1.5hrs endurance set on normal or 45 mins set to max). As we were well below MTOW I planned to carry additional TKS deicing fluid (and a funnel) in the baggage compartment so I could refil it up in Scotland and have some for the return flight, the chances of finding some on a Sunday in Cumbernauld (or anywhere else for that matter) would be pretty slim.
For weather briefing I used (my usual) -
1. BBC news 24 weather (as a general guide)
2. Metform 214/215 for the aviation "big picture"
3. TAFs/METARs (en route for alternates as well as for destination)
4. Significant Wx prognostic chart for cloud tops forecast (FL100+)
5. European Aviation Wx Centre for synoptic forecast (FL060-140)
6. Rainfall radar.
All are free online.
After looking at all the above I cancelled the flight, unbooked the hotel and gave the bad news to my pilot friend who was going to come along for the ride. He was disappointed but understood why.
Encountering severe unforecast weather last week was a wakeup call for me and raised my threshold for scratching a flight when the forecast looks pretty poor. Had I not got iced up last week I might have given it a try today. Maybe we could have made it, I don't know, I even considered running up the west coast at low level to Prestwick dodging the showers but coming back tomorrow would have been even more interesting.
Regrettably I won't be at the party in Glasgow tonight.
SB
I should have flown from Plymouth to Cumbernauld today but scratched the flight even though I hold a current IR and fly a nearly new known-ice approved aircraft (I filled up the TKS tank to capacity last night in preparation).
Looking out of my window here in Cornwall it's pretty frustrating because the conditions here are perfect for flying but I know that heading North over Wales things would deteriorate pretty quickly and with a freezing level around 500-1000ft around the trough that's heading Southwards any "sleet" (freezing rain) precip would stick to my airframe like glue - even with the TKS on "max" setting (which gives me 1.5hrs endurance set on normal or 45 mins set to max). As we were well below MTOW I planned to carry additional TKS deicing fluid (and a funnel) in the baggage compartment so I could refil it up in Scotland and have some for the return flight, the chances of finding some on a Sunday in Cumbernauld (or anywhere else for that matter) would be pretty slim.
For weather briefing I used (my usual) -
1. BBC news 24 weather (as a general guide)
2. Metform 214/215 for the aviation "big picture"
3. TAFs/METARs (en route for alternates as well as for destination)
4. Significant Wx prognostic chart for cloud tops forecast (FL100+)
5. European Aviation Wx Centre for synoptic forecast (FL060-140)
6. Rainfall radar.
All are free online.
After looking at all the above I cancelled the flight, unbooked the hotel and gave the bad news to my pilot friend who was going to come along for the ride. He was disappointed but understood why.
Encountering severe unforecast weather last week was a wakeup call for me and raised my threshold for scratching a flight when the forecast looks pretty poor. Had I not got iced up last week I might have given it a try today. Maybe we could have made it, I don't know, I even considered running up the west coast at low level to Prestwick dodging the showers but coming back tomorrow would have been even more interesting.
Regrettably I won't be at the party in Glasgow tonight.
SB
Joined: Aug 2003
Posts: 434
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From: UK
Going off at a slight tangent here, but why do so many pilots seem to not realise that the weather FORECAST is exactly that - it's an opinion of what COULD happen and not what WILL happen ?
If you'd like a slightly different perspective of met forecasting I'd recommend checking out
http://glidemet.co.uk/ (ok, it's primarily for glider pilots but covers met in Southern England). One of the great things a bout the site is that it often provides an aftercast analysis - i.e. why the forecast was wrong.
If you'd like a slightly different perspective of met forecasting I'd recommend checking out
http://glidemet.co.uk/ (ok, it's primarily for glider pilots but covers met in Southern England). One of the great things a bout the site is that it often provides an aftercast analysis - i.e. why the forecast was wrong.
Joined: Apr 2008
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From: Criccieth
Using an anonymous identity? Is this a joke?
Or is this a "self-appointed" role, a la Mugabe? Is your real name Robert?
Joined: Aug 2000
Posts: 3,648
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From: UK
So, Pudnucker and robin, which forecasts were you misled by? Dorset and Exeter, huh?
This one?
TAF EGHH 120853Z 121019 24010KT 9999 SCT020 TEMPO 1019 24015G25KT 7000 SHRA SCT020CB PROB30 TEMPO 1219 4000 +SHRAGS TSRA BKN014CB=
which doesn't seem particularly pessimistic given
METAR EGHH 121120Z 28019G30KT 9999 6000S FEW018 SCT032CB 07/05 Q1005 RESH=
Or this one?
TAF EGTE 120853Z 121019 24010KT 9999 SCT020 PROB40 TEMPO 1019 24015G25KT 6000 SHRA SCT020CB=
which again doesn't seem conservative given
METAR EGTE 121150Z 23010G20KT 9999 8000NW VCSH SCT015 SCT025CB 10/06 Q1005=
Some of the convection over the UK did turn into thunderstorms:
METAR EGYD 121350Z 23017KT 9999 -TSRA BKN022CB SCT060 07/02 Q1002 WHT=
I tend to agree with XX621 that much of the problem is with the interpretation of weather forecasts, sometimes by people who should know a lot better. That you managed to go out yesterday and find decent skies between the showers doesn't mean the showers weren't there!
This one?
TAF EGHH 120853Z 121019 24010KT 9999 SCT020 TEMPO 1019 24015G25KT 7000 SHRA SCT020CB PROB30 TEMPO 1219 4000 +SHRAGS TSRA BKN014CB=
which doesn't seem particularly pessimistic given
METAR EGHH 121120Z 28019G30KT 9999 6000S FEW018 SCT032CB 07/05 Q1005 RESH=
Or this one?
TAF EGTE 120853Z 121019 24010KT 9999 SCT020 PROB40 TEMPO 1019 24015G25KT 6000 SHRA SCT020CB=
which again doesn't seem conservative given
METAR EGTE 121150Z 23010G20KT 9999 8000NW VCSH SCT015 SCT025CB 10/06 Q1005=
Some of the convection over the UK did turn into thunderstorms:
METAR EGYD 121350Z 23017KT 9999 -TSRA BKN022CB SCT060 07/02 Q1002 WHT=
I tend to agree with XX621 that much of the problem is with the interpretation of weather forecasts, sometimes by people who should know a lot better. That you managed to go out yesterday and find decent skies between the showers doesn't mean the showers weren't there!