US award for Mayo's woman's D-Day forecast

trmartin · 19-06-2021 8:28pm #1

See this link on the RTE web site for a story by Teresa Mannion on an award to be presented to Maureen Sweeney by the US House of Representatives in honour of her weather forecast about an impending storm in June 1944 which changed the timing of the D-Day landings:

https://www.rte.ie/news/2021/0619/1229119-maureen-sweeney/

odyssey06 · 19-06-2021 8:42pm

This is what happens when a Mayo man ends up in the White House

Just trying to follow the article...
"The remote Blacksod lighthouse and coastguard station played a key role during World War II supplying Britain with weather reports. Ted and Maureen Sweeney were amongst those taking readings on an hourly basis, which were being secretly phoned into London."

She wasn't actually the one sending the reports to London though, right?
I'm not clear on how her forecasts were communicated \ picked up and relayed to the British & Americans?

The One Doctor · 19-06-2021 9:57pm

odyssey06 wrote: »

This is what happens when a Mayo man ends up in the White House

Just trying to follow the article...
"The remote Blacksod lighthouse and coastguard station played a key role during World War II supplying Britain with weather reports. Ted and Maureen Sweeney were amongst those taking readings on an hourly basis, which were being secretly phoned into London."

She wasn't actually the one sending the reports to London though, right?
I'm not clear on how her forecasts were communicated \ picked up and relayed to the British & Americans?

Telegraph or Morse via radio.

jackboy · 19-06-2021 9:59pm

odyssey06 wrote: »

This is what happens when a Mayo man ends up in the White House

Just trying to follow the article...
"The remote Blacksod lighthouse and coastguard station played a key role during World War II supplying Britain with weather reports. Ted and Maureen Sweeney were amongst those taking readings on an hourly basis, which were being secretly phoned into London."

She wasn't actually the one sending the reports to London though, right?
I'm not clear on how her forecasts were communicated \ picked up and relayed to the British & Americans?

I thought she was just taking measurements and passing on the data, which is nothing remarkable. I think the forecasts were being done by someone else.

odyssey06 · 19-06-2021 10:06pm

The One Doctor wrote: »

Telegraph or Morse via radio.

I thought perhaps there might have been a bit of sensitivity wrt to the data but seems like it was just shared to the UK met office but seems like I was over-thinking it:

Maureen sent her readings to Ballina, Co Mayo, where they were sent to Dublin, then to the UK meteorological office in Dunstable, 50km north of London.

https://www.irishexaminer.com/lifestyle/arid-30928529.html

Hammer Archer · 20-06-2021 8:50am

Probably the more important observations that she sent weren't the ones that helped forecast the storm on June 5th (which was also forecast by the Germans), but more so the brief clearing that happened on June 6th that allowed D-day to go ahead that day. The Germans had concluded that the stormy start to June would have made an invasion impossible so stood down a number of their forces defending the beaches. They didn't receive any observations from the Irish Met Service and had little data from the North Atlantic.
Had they not gone ahead with D-Day on June 6th, the alternative date was June 19th. The Allies' meteorologists all predicted near perfect conditions that day so the invasions would have almost certainly gone ahead then had they not done so on June 6th. But a "storm" hit the area that day and lasted for three days which could have caused issues had the invasion gone ahead then.

So her observations along with the fact that they were only shared with the Allies and not the Nazis certainly can be credited with helping to ensure that the D-Day landings went ahead successfully.

Danno · 20-06-2021 3:18pm

A lovely recognition, pity they left it so long to award her.

UDAWINNER · 20-06-2021 3:25pm

goes against the theory that we were neutral, doesn't it?

riffmongous · 20-06-2021 3:29pm

I was googling it and found an article from a few years ago telling the story, in a slightly different way where the focus is almost all on her husband instead, fascinating to compare the two

https://www.independent.ie/irish-news/how-blacksod-lighthouse-changed-the-course-of-the-second-world-war-30319681.html

redsteveireland · 20-06-2021 3:54pm

I have heard a different story of a Mayo forecaster playing a role in this too, may have been romantised a little over the years.

towger · 20-06-2021 8:17pm

UDAWINNER wrote: »

goes against the theory that we were neutral, doesn't it?

We were neutral, but the saying was “neutral against who ?”

Tyrone212 · 20-06-2021 9:44pm

Strange. How often would the weather be inclement on the west coast here and then go to affect NW France especially during Summer. Not very often I would say. That was a big determination to make because of crap weather on the West Coast here. More often than not it would head NE not SE.

riffmongous · 21-06-2021 8:23am

Tyrone212 wrote: »

Strange. How often would the weather be inclement on the west coast here and then go to affect NW France especially during Summer. Not very often I would say. That was a big determination to make because of crap weather on the West Coast here. More often than not it would head NE not SE.

It did head NE actually, but the associated front was a over a thousand kilometres long and on the 5th stretched all the way down the North sea from Norway to the Channel.

I've been trying to figure out the full story, it seems they knew from their observations from the other side of the Atlantic that a storm was coming, the Americans predicted using a method based off of historical patterns that it wouldn't arrive in time or would miss and the 5th should be invasion day. The British thought otherwise using their method based on synoptic charts. Every single day was critical because a) they had a limited tidal window where it would be possible to land their ships and b) the high command were extremely worried that the invasion buildup would be discovered by the Germans. The observations from the 3rd confirmed that the storm and front had arrived and the landing scheduled for the 5th was postponed. The observations from the 4th then indicated the front had passed and the forecasters could then extrapolate that the 6th would be ok to go ahead.

If the landing had gone ahead on the 5th it probably would have been a disaster, high winds, rough seas and no air support. If it had been delayed to the next window in June the chance of it being discovered and German reinforcements strengthening the defences would have increased and in addition the weather was also very poor

Hammer Archer · 21-06-2021 11:01am

UDAWINNER wrote: »

goes against the theory that we were neutral, doesn't it?

I think the official line was that we were sharing weather observations with the UK and not sharing them with the Germans before WWII, so that arrangement continued throughout the war.

riffmongous wrote: »

It did head NE actually, but the associated front was a over a thousand kilometres long and on the 5th stretched all the way down the North sea from Norway to the Channel.

I've been trying to figure out the full story, it seems they knew from their observations from the other side of the Atlantic that a storm was coming, the Americans predicted using a method based off of historical patterns that it wouldn't arrive in time or would miss and the 5th should be invasion day. The British thought otherwise using their method based on synoptic charts. Every single day was critical because a) they had a limited tidal window where it would be possible to land their ships and b) the high command were extremely worried that the invasion buildup would be discovered by the Germans. The observations from the 3rd confirmed that the storm and front had arrived and the landing scheduled for the 5th was postponed. The observations from the 4th then indicated the front had passed and the forecasters could then extrapolate that the 6th would be ok to go ahead.

If the landing had gone ahead on the 5th it probably would have been a disaster, high winds, rough seas and no air support. If it had been delayed to the next window in June the chance of it being discovered and German reinforcements strengthening the defences would have increased and in addition the weather was also very poor

The US forecasting team were adamant that the invasion should go ahead on June 5th. There were three forecasting teams at the time, one from the US Army, one from the RAF and another from the Royal Navy and the US team tried to sway one of the UK teams and make it 2-1 to go ahead on the 5th. Like you said, it probably would have been a disaster had that happened.

On the 19th, the alternative D-Day, there were reports of it being the worst storm of the 20th century so far. But looking at the reanalysis charts of that day, while the weather wouldn't have been perfect (the winds did destroy some floating harbours), it was nowhere near as bad as was reported as far as I can see.

piuswal · 21-06-2021 11:54pm

jackboy wrote: »

I thought she was just taking measurements and passing on the data, which is nothing remarkable. I think the forecasts were being done by someone else.

That is what was happening. All Irish Weather Observing Stations transmitted their reports to Dublin and from there they went onto Dunstable, I think it was. This was part of a world wide arrangement of exchanging weather observations which is still in existence today. The Irish, Dev's I suppose, viewpoint was that they were merely fulfilling their international obligations and if the British were not forwarding them to all of their pre war contacts, that was their business and they were not living up to their international obligations.

Yes, it was simply weather observations that were sent from Blacksod and the other Irish Stations.

It's a pity that so many reports and reporters mix up weather obsevations and weather forecasts, Even the plaque at Blacksod Lighthoues refers to the D Day Forecast from there, which is incorrect. It wa unveiled by Larry Wren, one time Garda Commissioner.

There were in fact 3 Forecasting Teams; The job of predicting the English Channel’s famously fickle weather fell to teams of meteorologists from the U.S. Army Air Corps, the British Royal Navy, and the British Meteorological Office.

They used different techniques and came up with different forecasts.

Group Capt Stagg's job was to try and elicit a consensus to present to Eisenhower and the Allied Top Brass.

Blacksod's critical role was an observation that confirmed one of the forecasts that indicated an improving period on June 6th and on the basis of this Eisenhower held the landings for 24 hours and the rest is history.

The German forecast for the period was better that the Allies and because even the respite gave conditions above what were considered safe thresholds for the landings they, logically, assumed they would not take place and Rommel went home to visit his wife on her birthday.

Eisenhower was aware that even the respite condtions were above the planners thresholds but decided to take the risk. The next optimum period, moon and tidal conditions, would be another 3 weeks away and he was afraid that the Germans would be aware that Normandy was the target and deploy their forces, especially their Panzers accordingly and so create a much greater obstacle to the Allies.

As it turns out 3 weeks later saw one of the worst Channel Summer storms in history and great damage was done to the artificial harbours,the Mulberries but of course by that stage the Allies were well established in Normandy.

US award for Mayo's woman's D-Day forecast

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