The D-Day Weather Map - Objectivity 297

0:00 Hi there everyone.

0:00 Welcome to the Met office here in the UK.

0:03 This is the weather and climate service for the entire country.

0:06 Full of weather maps here in the archive.

0:08 But today, Katherine Ross, the head of the archive here, is going to show us,

0:13 I'm going to say it, the most important weather map in all of history.

0:19 Ever.

0:22 Do you believe me?

0:23 Let's go and have a look.

0:25 I believe you.

0:26 You believe me?

0:27 Well, you think it is.

0:28 Here we go.

0:30 Massive spoiler, James.

0:31 Look at this.

0:33 So, here we go.

0:34 Here is a map.

0:35 Clearly, we can see Europe.

0:38 We can see the UK.

0:40 We can see Britain.

0:42 We can see the Atlantic Ocean.

0:43 We can even see Iceland and Greenland.

0:45 So, this is Europe.

0:46 And if you haven't figured out already, these maps are all about D-Day.

0:51 Do you think everyone knows what D-Day is?

0:53 Well, if they don't, D-Day was 6th of June, 1944.

0:58 And it was when the Allied forces landed on the beaches in Normandy

1:03 and France to basically start the fight back in World War II.

1:07 This was the turning point of World War II.

1:09 This was kind of the counter offensive when the Allies

1:12 went back into Europe and took on the Nazis.

1:15 Tell me about how these maps fit into the story and why they're so important.

1:20 It's the largest seaborn invasion in history.

1:23 Um, you can have all the stars aligned.

1:25 Everything can be perfect.

1:27 If you haven't got the right weather, you're not invading.

1:30 Speaking of the stars aligning though, the moon was a factor here, wasn't it?

1:33 Yeah.

1:34 Moon and tide had to be right.

1:35 Yeah.

1:36 So, that only gives you a certain number of days you can choose from.

1:39 Then the weather's got to be right as well.

1:42 So, the odds were more than stacked against them.

1:44 And the plan was to invade on the 5th of June.

1:47 Everything was ready.

1:48 Only one problem.

1:49 The weather wasn't good enough.

1:51 Okay.

1:51 Okay.

1:51 And so this chart is for the 5th of June.

1:53 We can see it up here.

1:54 It says Air Ministry Meteorological Office, Monday 5th of June, 1944.

2:00 And this forecast is basically, well, I don't know.

2:03 To me, it's just a bunch of numbers and squiggles and lines,

2:05 but this was no good.

2:06 In order to decide whether you're going to invade on the 5th,

2:09 you've got to make that decision on the fourth.

2:11 So on the fourth, they're looking at their observations and they're forecasting,

2:15 we don't think the weather's going to be good enough on the fifth.

2:18 So this chart shows us they got that.

2:20 absolutely bang on right.

2:22 So this isn't the forecast.

2:23 No, this is actual observation.

2:25 This is what actually happened.

2:26 And it turns out they were right.

2:28 The weather was rubbish.

2:29 So this blue line here is a cold front.

2:31 Fronts bring rain, wind, cloudy conditions,

2:36 all the things you don't really want.

2:37 And it would have been very choppy at sea.

2:39 The gliders wouldn't have been able to fly over.

2:41 No airborne operations possible.

2:44 So you know, totally impossible to invade basically.

2:47 So this is Normandy where they landed and they

2:49 would have been starting from all across here.

2:52 Yeah.

2:52 All all the way along this side of the south coast.

2:55 So I mean what you can see from here,

2:57 not just this this macking great weather front.

2:59 These are called station symbols.

3:01 So they show us the observations at weather stations.

3:04 And probably one of the key things you can pick out is in these circles.

3:07 They draw how much cloud there is.

3:09 So basically the more lines then you've got full cloud.

3:12 So it's completely cloudy here.

3:14 It's completely cloudy here.

3:15 It's completely cloudy over here in the channel and the isobars here.

3:19 So these tell us the direction of the wind.

3:21 Wind will go down these lines.

3:23 But the closer they are together, the stronger the wind is.

3:26 So you can see these isobars are in our opinion quite tight.

3:29 This this means it's windy.

3:30 This sort of thing over here where they're further apart means lighter winds.

3:34 Okay, we've gone back.

3:36 We've gone back in time.

3:36 We've gone to the 4th of June,

3:38 the day before what would have been D-Day but wasn't D-Day.

3:41 Um, okay.

3:42 So this was the this was the weather

3:44 the day before planned D-Day 2 days before actual D-Day.

3:48 So what happens when you're doing synoptic weather

3:50 forecasting which is what was happening here before computers.

3:53 So you take your observations and then about every

3:56 1 hour actually at the when it's really really important

3:59 you take them again and you plot them again

4:00 and then you can see how your weather fronts are moving.

4:03 You can see how the weather patterns are moving.

4:05 So the forecasters would have been looking at this.

4:08 Yep.

4:08 On the fourth.

4:09 On the fourth and going that's going to be here tomorrow.

4:12 So the plan to go on the 5th.

4:14 They're saying no don't do it.

4:15 Who actually is doing this?

4:16 Who's got this massive responsibility?

4:19 So there's a guy called James Stag, group captain James Stag.

4:22 He was a meteorologist.

4:23 He was given rank basically so that he

4:25 could talk to Eisenhower and the joint chiefs.

4:28 So he was the lead meteorologist.

4:30 He was working with a team.

4:32 So he was working with um American milit meteorologists,

4:35 UK meteorologists and they all had to try

4:38 and agree on whether they think the weather's going

4:40 to be good enough and then he stag

4:42 would then take that decision or make that decision.

4:45 If nobody could actually agree, he had to take final responsibility

4:49 and then take that to Eisenhower, General Eisenhower.

4:52 He says we go or we don't go.

4:54 Have we ever heard from Stag

4:57 as to how heavily that responsibility weighed on him?

5:00 Yeah, we've got his diary actually.

5:02 Okay, we've popped upstairs now for a quick look at the stag diary.

5:05 This is amazing.

5:07 Have a look at the front diary 1944.

5:10 D-Day diary historic document keep HM stationary office.

5:15 I love all this stuff.

5:16 Here are the big days in question.

5:18 June 3, June 4, June 5.

5:21 Let's have a look at June 4,

5:22 the day before what was going to be D-Day until they called it off.

5:27 Yes.

5:27 So this is stag chief forecaster you desperately

5:30 trying to find a solution in that weather

5:32 and he says I am now getting rather stunned it is all a nightmare right

5:37 the pressure's on so he wrote that diary on the day he was looking

5:40 at this very map and going am I can we do this can't we do this okay

5:45 so he said don't go on the fifth don't go on the fifth so when

5:48 we look at the map for the fifth he's vindicated there's this front as you

5:52 told us it would have been horrendous if they had done D-Day luckily they didn't

5:56 but he's now looking at this and got to decide can we go on the sixth.

5:59 Yeah.

6:00 And moon and tide are only right on those few days.

6:03 You can't push it over to the seventh.

6:04 It's you know the moon and tide are wrong.

6:05 So he's it's it's we go or we don't go in the next 24 hours.

6:09 I'm getting chills just thinking about it.

6:10 As I say, it was really marginal.

6:12 Not everybody agreed on this.

6:14 So he's looking at this.

6:15 We got it right.

6:16 Then he's looking here and he's looking at this thing

6:19 with an H in the middle of it.

6:20 H means high pressure.

6:22 This is sitting out over the Atlantic.

6:23 How is he getting measurements from the Atlantic Ocean?

6:26 I see there are stations here.

6:27 There's not land here, is there?

6:29 No.

6:29 So, these will be ships.

6:30 I There's the odd island out here as well,

6:32 but certainly these are all ship observations,

6:35 but there's still a few Ubot around at this time.

6:38 So, obviously, if you break radio silence,

6:40 then you know, you're potentially asking to be torpedoed.

6:43 So, this isn't something they would have done ordinarily all the time,

6:46 but they will have received essentially a code of message saying,

6:48 "We need your observations." Because they're looking

6:51 to see that low pressure coming in.

6:52 Yeah, it's coming.

6:53 Yeah, we've got a problem.

6:54 Now, they're looking for high pressure.

6:55 Can we see the high pressure coming in?

6:57 Are things looking better?

6:58 They think is this going to be the savior and push away?

7:01 Yeah, absolutely.

7:02 Obviously, we all know what the call was go.

7:05 But was it was it given with any qualification?

7:07 Was it go but don't blame me if it rains or was it how like do we know anything?

7:12 Kind kind of.

7:13 And now we go to Monday, June 5th.

7:16 This is where he makes the call.

7:18 What have we got?

7:19 What's what's being said?

7:20 Yeah.

7:20 So, fair interval confirmed.

7:22 We've decided we've got it.

7:23 An invasion put on.

7:25 final and irrevocable decision.

7:27 Whatever the outcome, the decision is taken.

7:30 Here we have a bit about the congratulations and he's having some doubts.

7:33 What's what's what does he say?

7:34 Yes.

7:34 So yeah, he he has got some some doubts.

7:36 He knows it's marginal.

7:37 So you got Admiral Cesy here and Admiral Cesy

7:39 said you should be proud of yourself and your forecast.

7:43 And then Stag's response is I wonder he should wait till he sees how things go.

7:49 All right.

7:51 Now the next map shows us what what actually happened.

7:54 Here we go.

7:55 Here is the 6th of June.

7:57 Dday itself.

7:58 Dday.

7:59 Yeah.

7:59 This is a high here.

8:01 I don't see any blue lines or That's all the way over here now.

8:04 So that's well out the way.

8:05 Here's the blue line here.

8:06 There's the front.

8:07 It's moved across Europe giving reasonable weather.

8:11 I believe reasonable but borderline.

8:13 So here's the high pressure, but what they wanted that pressure to be was here.

8:18 So here's your nice widely spaced isobars with your light winds.

8:22 They aren't here.

8:23 These are although not as tight as they were yesterday,

8:27 you know, these are still reasonably tight isobars.

8:30 So, it was still quite windy.

8:31 It was choppy, you know,

8:32 and you can still see here we've still got some cloud symbols across the coast.

8:37 The black lines there pointing down in the little circles there.

8:40 That's what you're after.

8:41 The red lines show you how cloudy it was in the last hour.

8:43 So, it was still cloudy, but if you have a look at this one down over Normandy,

8:48 you can see there's only one line in that circle.

8:50 So, not crazy cloudy,

8:52 which is why the the airborne operations were able to take place.

8:56 It wasn't perfect, but it was just about Well, here's the question then.

9:00 Obviously, D-Day was a horrendous event, but ultimately,

9:04 I guess you'd have to call it successful.

9:06 You know, it turned the war.

9:08 Did Stag get it right?

9:09 Like, should they have gone that day?

9:11 How does weather history judge this call?

9:14 So weather history judges correctly in my opinion this as the most

9:18 important forecast the Met Office has ever made and a correct forecast.

9:21 It was correct.

9:22 It was it was correct.

9:24 It was marginal but it was the right side of marginal.

9:27 It was good enough.

9:28 One of the things that really helps us with that um

9:31 is that you know it wasn't just that the allies had forecasters,

9:34 the Germans had forecasters too.

9:36 Right.

9:36 And so their weather forecasters had the job

9:38 of predicting what the British forecasters were predicting.

9:42 Correct.

9:42 Yeah.

9:43 is an available to them.

9:49 Okay, so this isn't an original, is it?

9:51 This is the German map for what the same time or so it's almost the same time.

9:57 It's not quite, but um but this is a German map.

9:59 Again, you can see the the cold front.

10:01 Not quite in the same place as we've got it, but well out the way,

10:04 but what you can see here by comparison with here,

10:08 if we just line these up, that's the UK.

10:10 Yeah, that's the UK.

10:12 We've got loads of observations all over the UK.

10:14 They've got none or virtually none.

10:16 And where's the Atlantic?

10:18 They don't know about this high pressure.

10:20 Exactly.

10:20 They don't know about the high pressure.

10:22 So they advised that it wouldn't be possible

10:24 to invade if we'd been looking at glorious conditions.

10:27 A nice high pressure plonked right there, therefore right here.

10:32 They'd have known just as well as we

10:33 did that it was perfectly possible to invade.

10:35 Another thing, Katherine, that's really noticeable is, as you said,

10:38 no weather observations for the Germans, for Britain, or virtually none.

10:42 But the British are getting observations from Europe,

10:46 presumably parts of Europe that are even occupied.

10:48 Yeah, most of that.

10:49 How are they getting that?

10:50 Obviously, the British or the Allies had cracked the Enigma code.

10:53 So, they're reading all of the German radio traffic

10:56 and whether observations were part of that radio traffic.

10:59 So the British sitting up in Bletchley Park are picking it all up, decoding it,

11:03 and then the Allies are able to plot all of that data onto their maps.

11:07 So it kind of comes down to a war of data, and the Allies had more.

11:10 I tell you who I think some real unsung heroes are.

11:14 The people who were sending in these forecasts

11:16 out at the Atlantic that the Germans didn't have.

11:19 They're breaking radio silence.

11:20 They could get torpedoed.

11:21 And that's the data that decides it, isn't it?

11:24 Yep.

11:24 That really helps us to know that, you know, there's a high pressure moving in.

11:28 Do you know what though?

11:29 This one here for the sixth is like the glamour map cuz it's D-Day.

11:33 But the real important map is the day before.

11:36 That's the map.

11:37 So this is often referred to as the D-Day map because it's D-Day.

11:41 But when we're telling the story, we always say really this is the D-Day map cuz

11:47 this is what they use to be able to make that decision.

11:50 So this is 1:00 in the morning and the conference where

11:53 they decided to go or no go was 3:00 in the morning.

11:56 And this is the actual map.

11:57 They would have been touching this one

11:59 and looking at this one and using this one.

12:00 Some of them would have been.

12:01 I mean, there'd have been a few copies of this around,

12:03 but yes, certainly some of the forecasters would have been using this.

12:07 Wow.

12:08 Well, I feel really lucky to get to see an actual copy like this.

12:12 It's uh Yeah, you feel you feel the weight of history when you look at it.

12:18 The thing I'm wondering is what's written for D-Day itself.

12:20 Let's turn the page and go to the 6th of June.

12:23 Not a lot.

12:24 No.

12:24 No.

12:25 Why not?

12:25 What?

12:26 What?

12:26 What?

12:26 His job's done, you know, for for you know, they're on the beaches.

12:30 You know, it's it's done.

12:31 Portsouth is where the decision is made.

12:32 So, he goes back from Portsmouth up to London.

12:35 Return from Portsouth.

12:36 You know, lunch at home by 2:30.

12:38 You know, I mean, he does mention some

12:40 concern about the weather because the cloud becomes 10/10,

12:43 which is full cloud cover, and the wind increases.

12:45 So, you know, caused me considerable worry at home,

12:48 but really too tired to be much concerned.

12:51 I mean, he's been up for the last 3 days.

12:53 This is really interesting.

12:54 He's He's having lunch at home back at home

12:56 at 2:30 while the while this is all still happening.

12:59 Absolutely.

13:00 Yes.

13:00 And it's on his mind, but he's also just completely shattered.

13:03 He's exhausted.

13:04 Yeah.

13:04 And he knows there's nothing he can do.

13:06 You know, it's it it works or it doesn't work, but it's out of his hands now.

13:10 This is amazing.

13:11 What a great thing to have.

13:12 It is amazing.

13:12 I'm going to give it back.

13:13 And don't forget, I'll keep it.

13:15 Keep it.

13:15 All right.

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13:46 Little bit of sun, little bit of sun, cloudy again.

13:49 And you can see here, Louisiana, at the end of the day,

13:51 they actually add up how much has been burnt

13:54 to tell how much sunshine there was that day.

13:56 Exactly.

13:56 So, 5.6 hours.