Operation Overlord postponed to 19 June

[Juan G. C.]

It is known that in the evening of June 4, 1944, general Eisenhower had to decide wether to launch Operation Overlord on June 6 o to postpone it to the next possible date, June 19. He decided to launch it on June 6. But what would had happened if he had decided to postpone it to June 19? On that date the biggest storm in half a century broke. How would it have affected the landings and the operation?

[History Learner]

IOTL it shut down reinforcements, resupply and air support for days, which obviously would most likely result in the failure of the landings on its own. However, Rommel would also be back from Germany at this time and thus would be in a position to compound this with ordering and managing an effective counter-attack.

[Richard Anderson]

It is known that in the evening of June 4, 1944, general Eisenhower had to decide wether to launch Operation Overlord on June 6 o to postpone it to the next possible date, June 19. He decided to launch it on June 6. But what would had happened if he had decided to postpone it to June 19? On that date the biggest storm in half a century broke. How would it have affected the landings and the operation?

The next window was 18-21 June. If it was put off till then the Great Storm would have resulted in a further two week delay, 2-5 July IIRC. The main result would have been slightly stronger German defenses, but the end result is likely the same.

[Juan G. C.]

The next window was 18-21 June. If it was put off till then the Great Storm would have resulted in a further two week delay, 2-5 July IIRC. The main result would have been slightly stronger German defenses, but the end result is likely the same.

AFAIK the great storm wasn't predicted by the weathermen, so there would have been no more delays and the Operation would have been launched on the first possible day (I don't know if 18 or 19 June).

[Richard Anderson]

AFAIK the great storm wasn't predicted by the weathermen, so there would have been no more delays and the Operation would have been launched on the first possible day (I don't know if 18 or 19 June).

What was not predicted, because it was unknown, was the damage the storm would do to the MULBERRIES. The storm itself was predicated, beginning to develop significantly on 16 June, when all tactical bomber missions flown from England were cancelled due to weather. Reported winds on the beachhead were Force 3 by 17 June and after a lull were predicated to reach Force 6 or 7 by 19 June and for two to three days after. It was a worse storm than that which delayed D-Day (that was an Atlantic storm moving east to west, predicted to reach Force 5-6), but led to similar circumstances in the invasion area. The predicted conditions were similar, if not worse, than those that resulted in the historical delay, so there is every reason to suppose it would have resulted in another delay.

A more interesting question is did Eisenhower make the right decision to go ahead with 6 June, but for the wrong reason? See, https://journals.ametsoc.org/view/journ ... 180311.xml

[Juan G. C.]

What was not predicted, because it was unknown, was the damage the storm would do to the MULBERRIES. The storm itself was predicated, beginning to develop significantly on 16 June, when all tactical bomber missions flown from England were cancelled due to weather. Reported winds on the beachhead were Force 3 by 17 June and after a lull were predicated to reach Force 6 or 7 by 19 June and for two to three days after. It was a worse storm than that which delayed D-Day (that was an Atlantic storm moving east to west, predicted to reach Force 5-6), but led to similar circumstances in the invasion area. The predicted conditions were similar, if not worse, than those that resulted in the historical delay, so there is every reason to suppose it would have resulted in another delay.

At least Dr. Lawrence Hogben, one of the six meteorologists who provided the Forecast for D-Day, said after the War that the storm wasn't predicted: "If we had been a little less certain and said no again, it would have had to shift to the 19th. As it happened, on the 17th, all six of us produced a forecast for the 19th for almost perfect conditions, so they would definitely have gone ahead. On 19 June the biggest storm of the 20th century came up. If they had landed that day, I doubt many landing craft would have even made it to the beaches. It does not bear thinking about" (From this article: https://weather.com/news/news/2019-06-0 ... ed-history). Perhaps he didn't remember well?

A more interesting question is did Eisenhower make the right decision to go ahead with 6 June, but for the wrong reason? See, https://journals.ametsoc.org/view/journ ... 180311.xml

Yes, I've read this article.

[Richard Anderson]

At least Dr. Lawrence Hogben, one of the six meteorologists who provided the Forecast for D-Day, said after the War that the storm wasn't predicted: "If we had been a little less certain and said no again, it would have had to shift to the 19th. As it happened, on the 17th, all six of us produced a forecast for the 19th for almost perfect conditions, so they would definitely have gone ahead. On 19 June the biggest storm of the 20th century came up. If they had landed that day, I doubt many landing craft would have even made it to the beaches. It does not bear thinking about" (From this article: https://weather.com/news/news/2019-06-0 ... ed-history). Perhaps he didn't remember well?

Possibly they did predict that on 17 June...I just realized I was giving the actual circumstances rather than the prediction. Nevertheless, whatever they predicted fell apart quickly. On 17 June the actual winds were Force 3 off the beaches and by the morning of 18 June (0600) were at Force 4 and increasing, while in the Channel measured winds were Force 5 in the morning and afternoon of 18 June. They then increased to between Force 7 and 9 on 19 June (accounts vary). Given the actual conditions on 17 and 18 June, no landing would have been carried out, despite what the prediction the morning of 17 June was; it would have been a repetition of the previous abort.

Yes, I've read this article.

Good.

[paulrward]

Hello All :

After staring out into the darkness on the evening of June 4th, General Eisenhower made the fateful
decision: The Invasion, D-Day, would be postponed until the next available date, June 17th. On that
night, the Airborne would take off, and the Sea-borne invasion would follow in the early light of June 18,
1944. " We can't afford to screw this up - we have to get it right the first time ! " Ike told Monty.

The night of June 17th found hundreds of C-47s and Horsa Gliders crossing the Channel, loaded with
their elite troops. The gliders made safe landings, and the C-47 crews dropped their paratroopers on
target and at the correct altitude. Within hours, the underbrush of Normandy was echoing with whispers
of " Flash ! " and " Thunder !" as the Screaming Eagles and All Amercans linked up into squads and platoons
and began wreaking havoc in the German rear areas behind the Beaches.

At first light on the 18th, the waves of LSTs and LCIs hit the beaches. Off Omaha Beach, the 'Donald Duck '
tanks managed to make the tough swim into shore, and, using their 75mm guns, suppressed the German
defenses, allowing the 'Big Red One', the US First Infantry Division, to storm ashore. At Utah, Gold, Sword,
and Juno Beaches, the Allies quickly seized their beachheads, and began preparing for the push inland to
link up with the Airborne. By Sunset on June 18th, All five landing beaches were secure, and President
Roosevelt made an address to the nation lauding the courage of the Allied Forces.

It was during the night of June 18th-19th that things began to go bad. The wind began to increase, and
by dawn on the 19th, the Channel was so choppy that it began to interfere with the loading of men onto
the landing craft from the transport ships. By noon, heavy rain storms were lashing southern England,
and both the RAF and USAAF found themselve grounded by the weather. The evening of the 19th was
so wet and the rain so severe that the Allied ground forces ashore could only huddle in the dark and rain
and wait for it to end.

June 20th was, for the Allies, even worse. The Channel Storm was now a Full Blown Gale. Transports
and warships were battened down, and the big guns of the Battleships and Cruisers were silent, the
seas being too rough for their gun crews sight their guns. The Allied Air Forces remained grounded,
and hundreds of landing craft, some caught on the beaches, others out at sea, were either washed
ashore or swamped in shallow waters, with hundreds of crewmen lost.

In England, it was increasingly obvious that a disaster was in the making, but there was nothing Ike
could do about it. The men on the beaches could be neither reinforced or re-supplied, nor could
they be withdrawn, and the scattered reports from behind the beaches from the Airborne forces
began to tell of German counter-attacks, attacks being carried out with support from Panzer units.
Without air support or naval gunfire to paralyze the German ground forces, the Wehrmacht began to
exploit areas of local superiority, and the lightly armed Airborne units suffered badly.

By the 21st, the situation had grown dire. During the night, the Germans had re-formed their
divisions, and, despite the pouring rain and high winds, they began to hit the British, Canadian,
and American forces on the Beachheads. The first to crack was Gold, followed within hours by
Sword and Juno. The British and Canadians fell first simply because it was here that the Germans
made their first major attacks. With little artillery ashore, and no air or gunfire support, the
Panzers simply over-ran the three eastern beachheads, and by nightfall of the 21st, all three
British beachheads had fallen to the Germans.

To the West, The Germans succeeded in overwhelming the 101st and 82nd Airborne divisions,
and on the morning of the 22nd, as the skies began to clear, the Heer threw it's full weight against
Omaha. Though the U.S. forces fought desperately, and at last began to get some air cover and
naval gunfire support, it wasn't enough. Thousands of U.S. infantrymen, driven into the surf,
were slaughtered by German forces. The sea at Omaha ran red with the blood of the G.I.s who
refused to surrender.

At Utah Beach, upon hearing of the collapse of the other four beachheads, the decision was
made to attempt a withdrawal. As the word spread, hundreds of Paratroopers began filtering
down to the beach. Under Allied Fighter cover which had, at long last, arrived, the USN and
Royal Navy succeeded in extricating nearly 25,000 men, but these men left behind their equipment,
their weapons, and worst of all, the aura of invincibility that the U.S. Army had acquired in the
ETO. The survivors were a broken force, and the loss of the two Airborne Divisions, the elite
of the U.S. Army, stunned Americans from the average man on the street to Marshall and Roosevelt.

As soon as the forces were withdrawn, ( though paratroopers were still being rounded up or killed
for another two weeks ), Eisenhower submitted his resignation as SCAEF. Under pressure from
Churchill, Monty was put in charge of the combined Armies until the situation could be improved.

There would be no invasion of France in 1944. The attack on Southern France was cancelled, and
the British and American forces continued their slow, dogged slog up the Italian Peninsula.

And in the East, at a meeting of the Politburo, Stalin puffed on his pipe and pronounced the
situation as, " Not what we had hoped for, but one which we will, nonetheless, find a way to
take advantage of. "


Respectfully :

Paul R. Ward

[Juan G. C.]

Possibly they did predict that on 17 June...I just realized I was giving the actual circumstances rather than the prediction. Nevertheless, whatever they predicted fell apart quickly. On 17 June the actual winds were Force 3 off the beaches and by the morning of 18 June (0600) were at Force 4 and increasing, while in the Channel measured winds were Force 5 in the morning and afternoon of 18 June. They then increased to between Force 7 and 9 on 19 June (accounts vary). Given the actual conditions on 17 and 18 June, no landing would have been carried out, despite what the prediction the morning of 17 June was; it would have been a repetition of the previous abort.

Given that IOTL Eisenhower, on the evening of 4 June, took the decision to lauch the Overlord on 6 June when the weather looked pretty bad, would the bad weather on 17 June have deterred him from launching It on 19 June if all the meteorologists predicted almost perfect conditions for that day? Unfortunately we do not know what the meteorologists forecasted on 18 June, which is the last time he could have aborted the Operation.

[Avalancheon]

The next window was 18-21 June. If it was put off till then the Great Storm would have resulted in a further two week delay, 2-5 July IIRC. The main result would have been slightly stronger German defenses, but the end result is likely the same.

If the invasion of Normandy is delayed by several weeks, that gives OKH and Hitler more time to clearly evaluate the situation on the Eastern front. They might have given more consideration to the intelligence reports showing that the Soviets were preparing to attack in Belorussia, not the Ukraine. (Actually, their reports predicted attacks on both regions) Perhaps the Germans would alter their plans.

One thing is certain, though. If Operation Overlord is delayed, there will be knock on effects for Operation Bagration. The Ostheer had armoured reserves in the form of the 9th and 10th SS panzer divisions that were in the Ukraine. In OTL, they were sent to France soon after Operation Overlord. In ATL, they would be available to deploy in Belorussia to meet Operation Bagration.

Their presence would have a significant impact on the outcome of the campaign. Even in OTL, the 5th panzer division was able to put a real crimp on the Soviets in Minsk. If the Red Army doesn't perform as well during Bagration, that will ripple effects for the Anglo-Americans.

[Sheldrake]

It is known that in the evening of June 4, 1944, general Eisenhower had to decide wether to launch Operation Overlord on June 6 o to postpone it to the next possible date, June 19. He decided to launch it on June 6. But what would had happened if he had decided to postpone it to June 19? On that date the biggest storm in half a century broke. How would it have affected the landings and the operation?

The next window was 18-21 June. If it was put off till then the Great Storm would have resulted in a further two week delay, 2-5 July IIRC. The main result would have been slightly stronger German defenses, but the end result is likely the same.

That was my first thought.

Two to four weeks delay in Op Overlord might have had two repercussions.

Further troops might have been dispatched to stabilise the situation in Italy. One Luftwaffe infantry division was dispatched in late May.

The Soviet Operation Bagration might still have taken place on 22nd June. Stalin would not have been happy that the Allies had failed to land before that date, but the significance of the fourth Anniversary of Barbarossa had significance. The troops most likely to be sucked into that battle would be II SS Panzer Corps.

A month or so might have allowed 1st SS 9th, 11th and 116th Panzer divisions to be closer to readiness, but was not likely to change the outcome.

[Juan G. C.]

Would Bagration have started as IOTL with a postponed/failed Overlord?

[Richard Anderson]

Given that IOTL Eisenhower, on the evening of 4 June, took the decision to lauch the Overlord on 6 June when the weather looked pretty bad, would the bad weather on 17 June have deterred him from launching It on 19 June if all the meteorologists predicted almost perfect conditions for that day? Unfortunately we do not know what the meteorologists forecasted on 18 June, which is the last time he could have aborted the Operation.

More importantly, given that in IOTL Eisenhower decided not to launch NEPTUNE without the airborne, he likely never would have decided to launch on 19 June, even though the tides met requirements. 19 June was a waning crescent moon, insufficient to meet the airborne requirements.

Anyway, the historical sequence was:

Y-Day 1 June
2130 3 June - MET team cannot reach consensus for conditions 5 June, nevertheless forces embarked and sailed based upon possibility of improvement
0430 4 June - deteriorating forecast, Channel winds Force 6-7, and decision for delay, fleet recalled
2130 4 June - improved forecast, decision to embark troops again
0500 5 June - conditions not improving (rain and winds Force 8), but decision to go

The corresponding alt-historical sequence then would be:

Y-Day 15 June
???? 17 June - MET team predicts good weather for 19 May
AM 17 June - wind Force 3 at the beaches
0600 18 June - wind Force 4 and increasing at the beaches
AM 18 June - wind Force 5 in the Channel
PM 18 June - wind Force 5 in the Channel
AM 19 June - wind Force 7-9 on the beaches

As you note the real question, albeit it a moot one because of the moon phase, is not what the MET team prediction was on 17 June, but rather what the MET team's prediction was on the morning of 18 June, given conditions were not improving, but getting worse?

You would also need to wonder how bull-headed Eisenhower would be, given the deteriorating conditions the night of 18-19 June and whether or not he would order the landing to go forward in gale conditions?

[paulrward]

Hello All

Mr. Richard Anderson stated :

You would also need to wonder how bull-headed Eisenhower would be, given the
deteriorating conditions the night of 18-19 June and whether or not he would order the
landing to go forward in gale conditions?

But Mr Anderson had earlier conceded that

Y-Day 15 June
???? 17 June - MET team predicts good weather for 19 May
AM 17 June - wind Force 3 at the beaches
0600 18 June - wind Force 4 and increasing at the beaches
AM 18 June - wind Force 5 in the Channel
PM 18 June - wind Force 5 in the Channel
AM 19 June - wind Force 7-9 on the beaches

What Mr. Anderson is apparently ignoring is that, for a landing on June 18th, the Airborne would
have to make their drops on the night of June 17th-18th ! In other words, Eisenhower, having
a Met Prediction on the Morning of June 17th of good weather until May 19th, would have no reason
to cancel the invasion. The Aircraft would take off, the gliders and paratroopers start landing at
about midnight, and now the invasion is going to have to go forward !

When, on the morning of June 18th, the wind on the beaches is Force 4, well, not good, but not
terrible..... in fact, historically less than on June 4th - 5th. If Eisenhower were to cancel the landing
at this point, it means he has thrown away two entire U.S. Airborne Divisions, plus all the British
Airborne that are, even at that moment, holding the ' Pegasus Bridge ' until they are relieved.....

Would Eisenhower cancel an Invasion landing while the sea conditions were still acceptable ( marginal,
but acceptable ) under those circumstances. If he did, he would be throwing away 17,000 men of
the 101st and 82nd divisions - that's a hell of a lot of letters to write to mothers and wives.....

No, Mr. Anderson, once the decision was made to invade, it meant that you had to send the Airborne
first, and that the invasion would HAVE to follow - no ifs, ands, or buts.

And that is why Eisenhower was smoking four packs of Cigarettes per day - chain smoking them, one
after another, for the weeks leading up to the day of the invasion. These ruined his lungs and his
heart, and shortened his life significantly.

Respectfully :

Paul R. Ward

Willy, Joe, and Ike

Willy Joe Ike.jpg (89.73 KiB) Viewed 2716 times

[Richard Anderson]

Yeah, this thread just jumped the shark.