WI: Overlord Weather Forecast Wrong?

June 5-6 was chosen for the full moon and the tides, with the 5th being cancelled due to weather. What if, for some reason, the speed of frontal passage is underestimated enough that the 6th is cancelled early, forcing a month's wait for the next full moon.

However I forget what the weather was like during the next full moon. Say the weather that night was bad too. (Does anybody have meteorological data links for July 5-6, 1944?)

What if July 5-6 had bad weather too, and THAT scrubs Overlord? Bagraton in the east would lead to a Brown Alert moment for the Western Allies, and they decide, "We can't wait anymore, we're taking the next tidal opportunity," and go for the following new moon...on July 20th.

Overlord goes in on the same day of the Bomb Plot IOTL. Does the bombing still happen, could there be enough butterflies to change it, basically, what would happen if the assassination attempt goes down on the same day as the invasion?
 
June 5-6 was chosen for the full moon and the tides, with the 5th being cancelled due to weather. What if, for some reason, the speed of frontal passage is underestimated enough that the 6th is cancelled early, forcing a month's wait for the next full moon.

Fallback option was mid-June without a full moon, but that also coincided with a storm.

Weather had different effects on different elements of the attack - the biggest impact of a storm was low cloud, reducing the effectiveness of air support. Montgomery was prepared to land on the 5th without air support, but it was Eisenhower's call.
 
Fallback option was mid-June without a full moon, but that also coincided with a storm.

Weather had different effects on different elements of the attack - the biggest impact of a storm was low cloud, reducing the effectiveness of air support. Montgomery was prepared to land on the 5th without air support, but it was Eisenhower's call.
I thought I remembered that about the June new moon.

Still, if the July full moon is a bust, the next best time is the 20th...
 
As it turn out the full moon was of little importance, the overcast & sea/ground level haze pretty much made it a no moon night.

The next date for tide conditions wanted was were 19, 20, 21 June, but that period saw a even worse storm start up.

The selection of conditions for the landing were a compromise between diverging needs of the components of the amphibious and air forces. Other compromises were possible. The main problem were the anti boat obstacles. Combined with mines those forced the first assault waves to attack at low tide, which is the opposite of what the assault force wants. But low tides occur at 28 different times in two weeks, so its a matter of choosing the next best low tide hour & then try to solve the other problems.
 
Very few times I've seen this attack examined from the view of everything going right.

1. No Overcast

Airborne not scattered & seize all the local bridges & related objectives.

Bombers have positive visual identification & the air strikes across Normandy are much more accurate. Specifically on OMAHA Beach the Resistance Nests guarding the beach exits each receive 200+ tons of bombs dead on.

Guide boats are not confused by haze obscured landmarks & the initial waves ground at the correct locations.

2. lower wind speeds

Boats are not blown easterly & the easterly tidal current is not wind driven to a higher speed.

DD tanks & other vulnerable landing vehicles not swamped by wind driven waves.

On the down side the invasion fleet is seen a hour or more earlier, & reports are more consistent. Thus reducing surprise & confusion at 7th Army HQ.

There a lot of other little details that can improve, but these weather related items can change without any action by multiple layers of command. the result is a much better concentrated and organized assault falls on a much more battered defense.
 
As it turn out the full moon was of little importance, the overcast & sea/ground level haze pretty much made it a no moon night.

The next date for tide conditions wanted was were 19, 20, 21 June, but that period saw a even worse storm start up.

The selection of conditions for the landing were a compromise between diverging needs of the components of the amphibious and air forces. Other compromises were possible. The main problem were the anti boat obstacles. Combined with mines those forced the first assault waves to attack at low tide, which is the opposite of what the assault force wants. But low tides occur at 28 different times in two weeks, so its a matter of choosing the next best low tide hour & then try to solve the other problems.
True, matters are getting desperate at this point anyway. The deception won't last much longer which risks Normandy being reinforced and with the Russians smashing through in the east the Allies really need to be ashore yesterday. That said going latter could see the Nazi's strip even more forces from France to send east but by then troop levels were already desperatly low anyway. Cutting much further could lead to the Marquis leadership deciding now's a good time for an uprising in advance of invasion. Since many of them are communist that's the last thing the Allies would want.
 
True, matters are getting desperate at this point anyway. The deception won't last much longer which risks Normandy being reinforced and with the Russians smashing through in the east the Allies really need to be ashore yesterday. That said going latter could see the Nazi's strip even more forces from France to send east but by then troop levels were already desperatly low anyway. Cutting much further could lead to the Marquis leadership deciding now's a good time for an uprising in advance of invasion. Since many of them are communist that's the last thing the Allies would want.
Better placed, but less troops defending would be a good angle, imagine the chaos of sending troops to the east, only to pull SS off the line to deal with uprisings.

I am curious on the Valkyrie part of my WI though. Does the assassination still get attempted ITTL if Overlord goes in on July 20th?
 
Better placed, but less troops defending would be a good angle, imagine the chaos of sending troops to the east, only to pull SS off the line to deal with uprisings.

I am curious on the Valkyrie part of my WI though. Does the assassination still get attempted ITTL if Overlord goes in on July 20th?
Probably not at that precise moment as D-Day and Bagaton seem to have been the last straw. If the plotters wait until the Allies are ashore and established again that puts things back into August at the earliest. Butterflies may see Hitler die, usual (rehashed infinitium) questions on outcome after that.

Also going before the Allies are fully ashore is risky if your plan is peace with the west but fight in the east as it doesn't leave the option open to just give up and let the allies win so they can take Germany before Stalin does. While the plotters had a (cackhanded )plan to negotiate the terms were unacceptable and with Stalin breathing down their neck letting the British and Americans win would quickly seem the least worst option.
 
Probably not at that precise moment as D-Day and Bagaton seem to have been the last straw. If the plotters wait until the Allies are ashore and established again that puts things back into August at the earliest. Butterflies may see Hitler die, usual (rehashed infinitium) questions on outcome after that.

Also going before the Allies are fully ashore is risky if your plan is peace with the west but fight in the east as it doesn't leave the option open to just give up and let the allies win so they can take Germany before Stalin does. While the plotters had a (cackhanded )plan to negotiate the terms were unacceptable and with Stalin breathing down their neck letting the British and Americans win would quickly seem the least worst option.
What if the communist uprisings provide enough motivation for the plotters to cover for the loss of motivation by a delayed Overlord? What if things are going so badly in France because Hitler ordered troops pulled to the east?

Would it be possible to change the desired terms by the plotters? Say, "We will fall back to prewar borders in the west, Italy, and with Denmark if you deal with the French communists so we can deal with the Soviets?" I'm not saying Churchill and Roosevelt would go for it, but that would that options plausibly enter the plotters minds?
 
What if the communist uprisings provide enough motivation for the plotters to cover for the loss of motivation by a delayed Overlord? What if things are going so badly in France because Hitler ordered troops pulled to the east?

Would it be possible to change the desired terms by the plotters? Say, "We will fall back to prewar borders in the west, Italy, and with Denmark if you deal with the French communists so we can deal with the Soviets?" I'm not saying Churchill and Roosevelt would go for it, but that would that options plausibly enter the plotters minds?
Its possible but Roosevelt won't stab Stalin in the back, Churchill would but he's not top dog anymore. That said if the plotters did it anyway they wouldn't complain and as OTL DeGaulle would take efforts to dismantle the resistance and/or get it into the army and under his control very quickly.

After that fight on for a bit, do a Rhine crossing and accept a surrender soon after when any new German government is out of options.
 
Its possible but Roosevelt won't stab Stalin in the back, Churchill would but he's not top dog anymore. That said if the plotters did it anyway they wouldn't complain and as OTL DeGaulle would take efforts to dismantle the resistance and/or get it into the army and under his control very quickly.

After that fight on for a bit, do a Rhine crossing and accept a surrender soon after when any new German government is out of options.
I concur, rosecelg isn't going to stab the soviets in the back.

However Truman and the rest of the military and government might, so let's say in this tl, Roosevelt dies a tid bit earlier or has health issues and doesn't run.

Honestly once D-day is afoot there is little to save Germany Hitler or no Hitler.

Now if Stalin said he wasn't stopping until the Atlantic and Constantinople.. Okay.. You might get peoples attention.

But 44 the Germans really don't have any leverage to play with and they have the soviets swarming like africanized killer bee's in the east and the west on shore.

So moving every thing east only stalks the Soviet advance and the west just walks in
could you imagine the outrage of the Soviet union, to west letting nazi Germany anywhere near off the hook? Or they not getting their glory. But late 44 the red army is a massive steam roller of epic proportions.

This would be a ademently violent anti western powers Soviet union if some deal was struck or if the west reneged on yalta or potsdam resulting in ww 2 going on a bit longer
 
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I concur, rosecelg isn't going to stab the soviets in the back.

However Truman and the rest of the military and government might, so let's say in this tl, Roosevelt dies a tid bit earlier or has health issues and doesn't run.

Honestly once D-day is afoot there is little to save Germany Hitler or no Hitler.

Now if Stalin said he wasn't stopping until the Atlantic and Constantinople.. Okay.. You might get peoples attention.

But 44 the Germans really don't have any leverage to play with and they have the soviets swarming like africanized killer bee's in the east and the west on shore
Which was always the biggest weakness of the plotters. Even if they do take over it will do no good and Germany's last hope is that they see this and get their heads out of their arses. It's still unconditional surrender or nothing but it would be surrender with millions less dead and the country less wreaked, which is really their only option for a good outcome at this point.
 
I concur, rosecelg isn't going to stab the soviets in the back.

However Truman and the rest of the military and government might, so let's say in this tl, Roosevelt dies a tid bit earlier or has health issues and doesn't run.

Honestly once D-day is afoot there is little to save Germany Hitler or no Hitler.

Now if Stalin said he wasn't stopping until the Atlantic and Constantinople.. Okay.. You might get peoples attention.

But 44 the Germans really don't have any leverage to play with and they have the soviets swarming like africanized killer bee's in the east and the west on shore
If FDR dies in July '44, Wallace is POTUS, and being a Soviet sympathizer, he wouldn't stab them in the back. I doubt Stalin would do something so rash either, however this is between Tehran and Yalta, so while division of Germany was already decided, the how wasn't. Stalin may demand the North German Plain as to put the Kiel Canal in Red hands, where you see a NATO South Germany that comprises Bavaria and Austria.

The idea above of a shift east coupled with a communist insurrection really has my attention, though.
 
Which was always the biggest weakness of the plotters. Even if they do take over it will do no good and Germany's last hope is that they see this and get their heads out of their arses. It's still unconditional surrender or nothing but it would be surrender with millions less dead and the country less wreaked, which is really their only option for a good outcome at this point.
Agreed.. Like yo.. He is dead.. White flag.. Game over. But I don't see the plotters doing that. .
 
If FDR dies in July '44, Wallace is POTUS, and being a Soviet sympathizer, he wouldn't stab them in the back. I doubt Stalin would do something so rash either, however this is between Tehran and Yalta, so while division of Germany was already decided, the how wasn't. Stalin may demand the North German Plain as to put the Kiel Canal in Red hands, where you see a NATO South Germany that comprises Bavaria and Austria.

The idea above of a shift east coupled with a communist insurrection really has my attention, though.
You are correct I keep forgetting about Wallace.. Either way I think the military would really speak up, and Churchill and de Gaulle would give birth to live goats in the event such a thought could transpire
 
Agreed.. Like yo.. He is dead.. White flag.. Game over. But I don't see the plotters doing that. .
Yeah very true, that was their biggest weakness in that they thought without Hitler they could salvage something from his gains or at least the pre 1937 borders. The Allies weren't having that and the only kind of coup they would accept was the kind that did exactly what you just said.
You are correct I keep forgetting about Wallace.. Either way I think the military would really speak up, and Churchill and de Gaulle would give birth to live goats in the event such a thought could transpire
Wallace wouldn't last long if he tried to make nice with the Soviets. Inspite of what was said in public the alliance was always one of desperation and things would always go back to "hate each other" five minutes after the end of the war. I suspect quiet pressure would be put on Wallace not to run (or else) and then somebody else gets the nod.
 
Wallaces Communist sympathies are exaggerated. He was naive, but he was also a businessman & former Republican. He'd been brought in to Roosevelts New Deal Cabinet to keep agribusiness viable & counter the socialist tendencies among the New Dealers where agriculture policy was concerned.. What I don't know is if Roosevelt kept him inside the information loop. How well was Wallace acquainted with Marshal, King, Dill, Arnold, Knox, Stimson, ect... If he understands and is confident with those guys then not a lot changes with US policy.
 
Wallaces Communist sympathies are exaggerated. He was naive, but he was also a businessman & former Republican. He'd been brought in to Roosevelts New Deal Cabinet to keep agribusiness viable & counter the socialist tendencies among the New Dealers where agriculture policy was concerned.. What I don't know is if Roosevelt kept him inside the information loop. How well was Wallace acquainted with Marshal, King, Dill, Arnold, Knox, Stimson, ect... If he understands and is confident with those guys then not a lot changes with US policy.
True and Roosevelt thought well enough of him to hand him the Sec Commerce post after the '44 election. That said the conservative democrats hated him (which is why he was bumped for Truman) so re-election could be difficult. It depends if the war looks won or not, if its going badly and FDR drops early they may still turn on him at the convention.

Especially as I wouldn't be surprised if Truman happened because elements in the party knew FDR was; if not dying then not terribly far off it and wanted to get their pick a heartbeat away from POTUS.
 
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