Battle of Britain

[Polynikes]

the chiefs of staff did discuss the speedboat option in July 1940 and decided it could not be stopped - but it's not a practical suggestion

Because they'd need a port to disembark the few soldiers carried on board.

[Leros87]

the chiefs of staff did discuss the speedboat option in July 1940 and decided it could not be stopped - but it's not a practical suggestion

According to Peter Schenk the Germans planned a diversionary operation using the bulk of 4 Company, I Bn, Brandenburg Regt, carried in 25 speedboats. Their role would have been to raid Dover harbour and its coastal batteries. It would seem that no one looked forward to being a part of this.

[Knouterer]

The possibility of an attack on Dover harbour by fast motor boats carrying commando units (the Brandenburger Regiment) is sometimes mentioned, and the Germans seem to have considered it, but it would seem that any such attack would have been suicidal considering the defences of Dover. The three twin 6pdrs alone – the latest addition to the Coast Artillery arsenal – could spit out 36 rounds per minute per barrel, or even more according to some sources, and would have reduced any attacking motor boats to matchsticks, as they did during an Italian attempt against Malta in 1941. There were AA machine guns on the breakwater as well (possibly also naval Pom-Poms?), and behind that there were 16 pillboxes along the waterfront (mostly manned by Home Guard and naval personnel). In any case, there would be no point in taking the harbour as long as the surrounding heights were not cleared of British troops, and the army garrison of Dover was about 8,000 strong by September, admittedly not first-class troops.
In that context, the commander of the 6in gun battery on the Eastern Arm, B.E. Arnold, in his memoirs of the war (Conflict across the Straits) relates that a friendly destroyer captain handed him nine Brens and one Boys AT rifle (with 17 rounds …) recovered from the Dunkirk beaches, and that he managed to hang on to these unauthorized weapons for quite a while, because his superiors when visiting the battery pretended not to see them.

[Harry Bold1]

There is an english version by now: Sealion ascending, as E Book and as paperback: https://www.amazon.co.uk/dp/B07NK7DMTZ

Hi, just read an alternative history novel, Seelöwe, the landing in England on the 21st of July 1940. Lots of senseful information on the planning and surprise landing in July which is primarily an Luftwaffe op.
There is an Ebook at: https://www.amazon.de/dp/B01N7LIVT9 and also a paperback version.
Reminds me a bit of Tom Clancys Red Storm Rising, comparable style.
I think it falls a bit short,regarding the logistical situation of the Luftwaffe in June and July in France. Would it really have been possible for the Wehrmacht to do this stunt?
What do you think?
Regretfully only in german language, though I hope an english version will follow.

[Knouterer]

Hitler gave the order to start preparing for an invasion of Britain on the 16th of July. On that same day, army engineers tested the first prototype of a landing craft on the Bodensee lake.
In other words, the idea that the Germans could have launched a full-scale invasion five days later is completely unrealistic. The Luftwaffe needed time to repair and overhaul planes, and to improvise new airfields on the Channel coast. In particular, the airborne forces had lost many aircraft and men in Holland and needed to be rebuilt.
The Channel ports from which the invasion would have to be launched were a shambles. For example, the newly appointed port commander of Dunkirk counted no fewer than 177 wrecks in and immediately in front of the harbour. Many could be left in place but others had to be raised or demolished in place before anything could be done with the port. Mines had to be swept, locks between the inner and outer harbour had to be repaired, etc. etc.
Even if we assume that the Germans could have sent over ten or twenty thousand men - without artillery or AFVs - in motor boats, fishing vessels and various other floating objects, and that the Royal Navy would somehow have missed them, local defenders would have had little trouble containing and defeating them. If necessary with the help of a few battalions of Foot Guards bused in from London.

[Paul Lakowski]

As was reported years ago, Admiralty fear a NORWAY style port to port invasion , that could land 100,000 to 200,000 troops with out much warning or ability for RN to prevent. Only thing every one agreed on was they could not count on reliable resupply. Mind you if the political situation in the UK was as terrible as THE DARKEST HOUR presents , then "Stannis Baratheon" could very well have caved in the British side in the midst of such an assault.

https://en.wikipedia.org/wiki/Stannis_Baratheon

https://en.wikipedia.org/wiki/Darkest_Hour_(film)

[AriX]

If germans taked "Kanalkampf" as their primary strategy , how it woukd affect the outcome of BoB?

[Aber]

https://www.bbc.co.uk/news/uk-england-kent-47577930

An unexploded World War Two bomb has been found on a disused airfield planned to be used as a lorry park in the event of a no-deal Brexit.
The bomb was found earlier at Manston Airport, Kent, and police and army bomb disposal experts were called in.

I have seen claims that this is actually the British pipe bomb for airfield demolition - more news should follow later

[History Learner]

This was brought to my attention by the user SpicyJuan:

Mathematical model shows how the Nazis could have won WWII's Battle of Britain

Now, historians and mathematicians from York St. John University have collaborated to produce a statistical model (docx download) capable of calculating what the likely outcomes of the Battle of Britain would have been had the circumstances been different.​
​
Would the German war effort have fared better had they not bombed Britain at all? What if Hitler had begun his bombing campaign earlier, even by just a few weeks? What if they had focused their targets on RAF airfields for the entire course of the battle? Using a statistical technique called weighted bootstrapping, the researchers studied these and other alternatives.​
​
"The weighted bootstrap technique allowed us to model alternative campaigns in which the Luftwaffe prolongs or contracts the different phases of the battle and varies its targets," said co-author Dr. Jaime Wood in a statement. Based on the different strategic decisions that the German forces could have made, the researchers' model enabled them to predict the likelihood that the events of a given day of fighting would or would not occur.​
​
"The Luftwaffe would only have been able to make the necessary bases in France available to launch an air attack on Britain in June at the earliest, so our alternative campaign brings forward the air campaign by three weeks," continued Wood. "We tested the impact of this and the other counterfactuals by varying the probabilities with which we choose individual days."​
​
Ultimately, two strategic tweaks shifted the odds significantly towards the Germans' favor. Had the German forces started their campaign earlier in the year and had they consistently targeted RAF airfields, an Allied victory would have been extremely unlikely.​
​
Say the odds of a British victory in the real-world Battle of Britain stood at 50-50 (there's no real way of knowing what the actual odds are, so we'll just have to select an arbitrary figure). If this were the case, changing the start date of the campaign and focusing only on airfields would have reduced British chances at victory to just 10 percent. Even if a British victory stood at 98 percent, these changes would have cut them down to just 34 percent.​

[Carl Schwamberger]

Designers of commercial war games have been building similar models into their Battle of Britain games since the 1970s. Results vary from one model to another.

[ljadw]

This was brought to my attention by the user SpicyJuan:

Mathematical model shows how the Nazis could have won WWII's Battle of Britain

Now, historians and mathematicians from York St. John University have collaborated to produce a statistical model (docx download) capable of calculating what the likely outcomes of the Battle of Britain would have been had the circumstances been different.​
​
Would the German war effort have fared better had they not bombed Britain at all? What if Hitler had begun his bombing campaign earlier, even by just a few weeks? What if they had focused their targets on RAF airfields for the entire course of the battle? Using a statistical technique called weighted bootstrapping, the researchers studied these and other alternatives.​
​
"The weighted bootstrap technique allowed us to model alternative campaigns in which the Luftwaffe prolongs or contracts the different phases of the battle and varies its targets," said co-author Dr. Jaime Wood in a statement. Based on the different strategic decisions that the German forces could have made, the researchers' model enabled them to predict the likelihood that the events of a given day of fighting would or would not occur.​
​
"The Luftwaffe would only have been able to make the necessary bases in France available to launch an air attack on Britain in June at the earliest, so our alternative campaign brings forward the air campaign by three weeks," continued Wood. "We tested the impact of this and the other counterfactuals by varying the probabilities with which we choose individual days."​
​
Ultimately, two strategic tweaks shifted the odds significantly towards the Germans' favor. Had the German forces started their campaign earlier in the year and had they consistently targeted RAF airfields, an Allied victory would have been extremely unlikely.​
​
Say the odds of a British victory in the real-world Battle of Britain stood at 50-50 (there's no real way of knowing what the actual odds are, so we'll just have to select an arbitrary figure). If this were the case, changing the start date of the campaign and focusing only on airfields would have reduced British chances at victory to just 10 percent. Even if a British victory stood at 98 percent, these changes would have cut them down to just 34 percent.​

These models are giving meaningless results, as losing the Battle of Britain would not force Britain to give up :Sea Lion would still be necessary ,and it would also be impossible .

[Carl Schwamberger]

These models are giving meaningless results, as losing the Battle of Britain would not force Britain to give up :Sea Lion would still be necessary ,and it would also be impossible .

Models are context dependant, context includes variables. The description posted is short on context, have to read the original docs to get a better idea what the designer were up to.

[History Learner]

This was brought to my attention by the user SpicyJuan:

Mathematical model shows how the Nazis could have won WWII's Battle of Britain

Now, historians and mathematicians from York St. John University have collaborated to produce a statistical model (docx download) capable of calculating what the likely outcomes of the Battle of Britain would have been had the circumstances been different.​
​
Would the German war effort have fared better had they not bombed Britain at all? What if Hitler had begun his bombing campaign earlier, even by just a few weeks? What if they had focused their targets on RAF airfields for the entire course of the battle? Using a statistical technique called weighted bootstrapping, the researchers studied these and other alternatives.​
​
"The weighted bootstrap technique allowed us to model alternative campaigns in which the Luftwaffe prolongs or contracts the different phases of the battle and varies its targets," said co-author Dr. Jaime Wood in a statement. Based on the different strategic decisions that the German forces could have made, the researchers' model enabled them to predict the likelihood that the events of a given day of fighting would or would not occur.​
​
"The Luftwaffe would only have been able to make the necessary bases in France available to launch an air attack on Britain in June at the earliest, so our alternative campaign brings forward the air campaign by three weeks," continued Wood. "We tested the impact of this and the other counterfactuals by varying the probabilities with which we choose individual days."​
​
Ultimately, two strategic tweaks shifted the odds significantly towards the Germans' favor. Had the German forces started their campaign earlier in the year and had they consistently targeted RAF airfields, an Allied victory would have been extremely unlikely.​
​
Say the odds of a British victory in the real-world Battle of Britain stood at 50-50 (there's no real way of knowing what the actual odds are, so we'll just have to select an arbitrary figure). If this were the case, changing the start date of the campaign and focusing only on airfields would have reduced British chances at victory to just 10 percent. Even if a British victory stood at 98 percent, these changes would have cut them down to just 34 percent.​

These models are giving meaningless results, as losing the Battle of Britain would not force Britain to give up :Sea Lion would still be necessary ,and it would also be impossible .

I agree that winning the Battle of Britain alone does not necessarily means Britain giving up or Operation Sea Lion having a high degree of success. Personally, I do agree a successful Sealion is unlikely, based on existing German amphibious capacity and logistical issues. Whether it can be a success is, however, a different question from whether it can be attempted and the strategic impacts of even a failed attempt. Likewise, I think those that dismiss the prospects of such do so at their own peril, given the historical record of WWII.

On paper, the Red Army in 1941 was better (at least materially) than the German Army and the logistical issues were obvious even before Barbarossa. Despite this, within six months Leningrad was under siege and it appeared likely Moscow would fall, with the RKKA having been decimated. Likewise, Imperial Japan managed to conquer the Pacific Basin on a shoestring budget logistically and force wise. The most prominent example in this regard was Singapore/Malay, where a smaller Japanese army with virtually no supplies by the end of it managed to, via decisive action, force a larger British force into surrender despite the latter being on the defensive. Sound familiar?

low probability =/= impossible

Still, as I said, I personally doubt such a landing would be a success. However, the wider strategic implications of Germany winning the Battle of Britain and then launching even a failed Sealion benefit them. Gaining air superiority over Southern England, especially London and Portsmouth, gives the Luftwaffe the ability to do to the British what the British did to them in 1943 in terms of seriously crippling the military industrial capacity of the UK's war machine; a land invasion would only compound this. Attrition of the RAF's best/most experienced pilots and forcing the British Army-still recovering from Dunkirk-to take heavy losses will require them to spend months if not a year or more rebuilding, limiting British options in other fronts. Finally, and the most obvious benefit to me, is London sending the Royal Navy on a death ride into the Channel. This has clear short and long term impacts that gravely effect their war effort going forward.

Even outside the issue of direct losses, a failed invasion is going to politically force Churchill and others to keep large numbers of forces deployed to Great Britain to deter another attempt. If, to make up for losses and deter another attempt, the RAF and Royal Navy are depleted in the Mediterranean, then that basically leaves the Italians to occupy Malta (Shutting down the Med in of itself) and overrun Egypt. Likewise, if Britain can't make meaningful commitments in that region, the Yugoslavs, Greece and Turkey are going to be changing their strategic calculus. No invasion and occupation of Yugoslavia/Greece, and Operation Barbarossa starts on June 10th with 12th Army as part of Army Group South too.

[ljadw]

This was brought to my attention by the user SpicyJuan:

Mathematical model shows how the Nazis could have won WWII's Battle of Britain

Now, historians and mathematicians from York St. John University have collaborated to produce a statistical model (docx download) capable of calculating what the likely outcomes of the Battle of Britain would have been had the circumstances been different.​
​
Would the German war effort have fared better had they not bombed Britain at all? What if Hitler had begun his bombing campaign earlier, even by just a few weeks? What if they had focused their targets on RAF airfields for the entire course of the battle? Using a statistical technique called weighted bootstrapping, the researchers studied these and other alternatives.​
​
"The weighted bootstrap technique allowed us to model alternative campaigns in which the Luftwaffe prolongs or contracts the different phases of the battle and varies its targets," said co-author Dr. Jaime Wood in a statement. Based on the different strategic decisions that the German forces could have made, the researchers' model enabled them to predict the likelihood that the events of a given day of fighting would or would not occur.​
​
"The Luftwaffe would only have been able to make the necessary bases in France available to launch an air attack on Britain in June at the earliest, so our alternative campaign brings forward the air campaign by three weeks," continued Wood. "We tested the impact of this and the other counterfactuals by varying the probabilities with which we choose individual days."​
​
Ultimately, two strategic tweaks shifted the odds significantly towards the Germans' favor. Had the German forces started their campaign earlier in the year and had they consistently targeted RAF airfields, an Allied victory would have been extremely unlikely.​
​
Say the odds of a British victory in the real-world Battle of Britain stood at 50-50 (there's no real way of knowing what the actual odds are, so we'll just have to select an arbitrary figure). If this were the case, changing the start date of the campaign and focusing only on airfields would have reduced British chances at victory to just 10 percent. Even if a British victory stood at 98 percent, these changes would have cut them down to just 34 percent.​

These models are giving meaningless results, as losing the Battle of Britain would not force Britain to give up :Sea Lion would still be necessary ,and it would also be impossible .

I agree that winning the Battle of Britain alone does not necessarily means Britain giving up or Operation Sea Lion having a high degree of success. Personally, I do agree a successful Sealion is unlikely, based on existing German amphibious capacity and logistical issues. Whether it can be a success is, however, a different question from whether it can be attempted and the strategic impacts of even a failed attempt. Likewise, I think those that dismiss the prospects of such do so at their own peril, given the historical record of WWII.

On paper, the Red Army in 1941 was better (at least materially) than the German Army and the logistical issues were obvious even before Barbarossa. Despite this, within six months Leningrad was under siege and it appeared likely Moscow would fall, with the RKKA having been decimated. Likewise, Imperial Japan managed to conquer the Pacific Basin on a shoestring budget logistically and force wise. The most prominent example in this regard was Singapore/Malay, where a smaller Japanese army with virtually no supplies by the end of it managed to, via decisive action, force a larger British force into surrender despite the latter being on the defensive. Sound familiar?

low probability =/= impossible

Still, as I said, I personally doubt such a landing would be a success. However, the wider strategic implications of Germany winning the Battle of Britain and then launching even a failed Sealion benefit them. Gaining air superiority over Southern England, especially London and Portsmouth, gives the Luftwaffe the ability to do to the British what the British did to them in 1943 in terms of seriously crippling the military industrial capacity of the UK's war machine; a land invasion would only compound this. Attrition of the RAF's best/most experienced pilots and forcing the British Army-still recovering from Dunkirk-to take heavy losses will require them to spend months if not a year or more rebuilding, limiting British options in other fronts. Finally, and the most obvious benefit to me, is London sending the Royal Navy on a death ride into the Channel. This has clear short and long term impacts that gravely effect their war effort going forward.

Even outside the issue of direct losses, a failed invasion is going to politically force Churchill and others to keep large numbers of forces deployed to Great Britain to deter another attempt. If, to make up for losses and deter another attempt, the RAF and Royal Navy are depleted in the Mediterranean, then that basically leaves the Italians to occupy Malta (Shutting down the Med in of itself) and overrun Egypt. Likewise, if Britain can't make meaningful commitments in that region, the Yugoslavs, Greece and Turkey are going to be changing their strategic calculus. No invasion and occupation of Yugoslavia/Greece, and Operation Barbarossa starts on June 10th with 12th Army as part of Army Group South too.

I have to disagree ,because you are going to fast and create/imagine connections where there are none .
LW air superiority over South-East Britain would have only very limited consequences,as the industrial centers of the UK were outside the zone where the LW could have air superiority : ex: Liverpool,Manchester,Yorkshire.
A failed landing would have been a catastrophe for Germany ,and air superiority would not make SL possible . There were several other conditions and if one was missing : NO SL .
The BoB/SL had also no impact on the outcome f the limited fighting in the Mediterranean/ NA.
For 2 reasons :
the British fores in that region were a mixture of UK and Imperial forces.
The British reinforcements were going to Egypt already before the defeat of the LW in September .
The Imperial forces would go to Egypt even if the LW had air superiority .
About the Balkans : the same was happening L the NZ would go to Greece,even if the LW had air superiority .
And the impact of the Balkans fighting on Barbarossa is a myth: the delay of Barbarossa was not caused by the fighting in the Balkans,but by the weather . Barbarossa before June 22 was out of the question .
Last point : 12 th Army ready for Barbaropssa : this also is a myth .
Germany knew that only a short/quick campaign where the Red Army was defeated in a few weeks could give it victory : a long campaign would give the Soviets the opportunity to mobilize their superior manpower and industrial resources and to use space and weather and time .
Thus,German victory did not depend on a stronger Ostheer (they could lose with a stronger Ostheer and win with a weaker )
Very simplified ,the German plan was
A Invasion of the SU
B The Red Army should go to the border (it was far away of the border ),where it would be defeated .If it did not go to the border,Barbarossa had failed before its started .
C Meanwhile,there would be something as July 20 1944, but in the Kremlin.
D This fighting would prevent the Soviets to mobilize
E The USSR would collapse.
The presence of 12 th Army was irrelevant for a German victory,.,as was the fighting in the Balkans . Besides,there is no relating between the outcome of the BoB and Marita,invasion of Yugoslavia and Mercury .
I forgot a point : Sealion would fail even without an intervention of the RN. And the LW was not strong enough to defeat Fighter Command (which always could withdraw to the North ) to stop counter-attacks by the Home Forces and to prevent the RN from intervening .

[History Learner]

This was brought to my attention by the user SpicyJuan:

Mathematical model shows how the Nazis could have won WWII's Battle of Britain

Now, historians and mathematicians from York St. John University have collaborated to produce a statistical model (docx download) capable of calculating what the likely outcomes of the Battle of Britain would have been had the circumstances been different.​
​
Would the German war effort have fared better had they not bombed Britain at all? What if Hitler had begun his bombing campaign earlier, even by just a few weeks? What if they had focused their targets on RAF airfields for the entire course of the battle? Using a statistical technique called weighted bootstrapping, the researchers studied these and other alternatives.​
​
"The weighted bootstrap technique allowed us to model alternative campaigns in which the Luftwaffe prolongs or contracts the different phases of the battle and varies its targets," said co-author Dr. Jaime Wood in a statement. Based on the different strategic decisions that the German forces could have made, the researchers' model enabled them to predict the likelihood that the events of a given day of fighting would or would not occur.​
​
"The Luftwaffe would only have been able to make the necessary bases in France available to launch an air attack on Britain in June at the earliest, so our alternative campaign brings forward the air campaign by three weeks," continued Wood. "We tested the impact of this and the other counterfactuals by varying the probabilities with which we choose individual days."​
​
Ultimately, two strategic tweaks shifted the odds significantly towards the Germans' favor. Had the German forces started their campaign earlier in the year and had they consistently targeted RAF airfields, an Allied victory would have been extremely unlikely.​
​
Say the odds of a British victory in the real-world Battle of Britain stood at 50-50 (there's no real way of knowing what the actual odds are, so we'll just have to select an arbitrary figure). If this were the case, changing the start date of the campaign and focusing only on airfields would have reduced British chances at victory to just 10 percent. Even if a British victory stood at 98 percent, these changes would have cut them down to just 34 percent.​

These models are giving meaningless results, as losing the Battle of Britain would not force Britain to give up :Sea Lion would still be necessary ,and it would also be impossible .

I agree that winning the Battle of Britain alone does not necessarily means Britain giving up or Operation Sea Lion having a high degree of success. Personally, I do agree a successful Sealion is unlikely, based on existing German amphibious capacity and logistical issues. Whether it can be a success is, however, a different question from whether it can be attempted and the strategic impacts of even a failed attempt. Likewise, I think those that dismiss the prospects of such do so at their own peril, given the historical record of WWII.

On paper, the Red Army in 1941 was better (at least materially) than the German Army and the logistical issues were obvious even before Barbarossa. Despite this, within six months Leningrad was under siege and it appeared likely Moscow would fall, with the RKKA having been decimated. Likewise, Imperial Japan managed to conquer the Pacific Basin on a shoestring budget logistically and force wise. The most prominent example in this regard was Singapore/Malay, where a smaller Japanese army with virtually no supplies by the end of it managed to, via decisive action, force a larger British force into surrender despite the latter being on the defensive. Sound familiar?

low probability =/= impossible

Still, as I said, I personally doubt such a landing would be a success. However, the wider strategic implications of Germany winning the Battle of Britain and then launching even a failed Sealion benefit them. Gaining air superiority over Southern England, especially London and Portsmouth, gives the Luftwaffe the ability to do to the British what the British did to them in 1943 in terms of seriously crippling the military industrial capacity of the UK's war machine; a land invasion would only compound this. Attrition of the RAF's best/most experienced pilots and forcing the British Army-still recovering from Dunkirk-to take heavy losses will require them to spend months if not a year or more rebuilding, limiting British options in other fronts. Finally, and the most obvious benefit to me, is London sending the Royal Navy on a death ride into the Channel. This has clear short and long term impacts that gravely effect their war effort going forward.

Even outside the issue of direct losses, a failed invasion is going to politically force Churchill and others to keep large numbers of forces deployed to Great Britain to deter another attempt. If, to make up for losses and deter another attempt, the RAF and Royal Navy are depleted in the Mediterranean, then that basically leaves the Italians to occupy Malta (Shutting down the Med in of itself) and overrun Egypt. Likewise, if Britain can't make meaningful commitments in that region, the Yugoslavs, Greece and Turkey are going to be changing their strategic calculus. No invasion and occupation of Yugoslavia/Greece, and Operation Barbarossa starts on June 10th with 12th Army as part of Army Group South too.

I have to disagree ,because you are going to fast and create/imagine connections where there are none .
LW air superiority over South-East Britain would have only very limited consequences,as the industrial centers of the UK were outside the zone where the LW could have air superiority : ex: Liverpool,Manchester,Yorkshire.
A failed landing would have been a catastrophe for Germany ,and air superiority would not make SL possible . There were several other conditions and if one was missing : NO SL .
The BoB/SL had also no impact on the outcome f the limited fighting in the Mediterranean/ NA.
For 2 reasons :
the British fores in that region were a mixture of UK and Imperial forces.
The British reinforcements were going to Egypt already before the defeat of the LW in September .
The Imperial forces would go to Egypt even if the LW had air superiority .
About the Balkans : the same was happening L the NZ would go to Greece,even if the LW had air superiority .
And the impact of the Balkans fighting on Barbarossa is a myth: the delay of Barbarossa was not caused by the fighting in the Balkans,but by the weather . Barbarossa before June 22 was out of the question .
Last point : 12 th Army ready for Barbaropssa : this also is a myth .
Germany knew that only a short/quick campaign where the Red Army was defeated in a few weeks could give it victory : a long campaign would give the Soviets the opportunity to mobilize their superior manpower and industrial resources and to use space and weather and time .
Thus,German victory did not depend on a stronger Ostheer (they could lose with a stronger Ostheer and win with a weaker )
Very simplified ,the German plan was
A Invasion of the SU
B The Red Army should go to the border (it was far away of the border ),where it would be defeated .If it did not go to the border,Barbarossa had failed before its started .
C Meanwhile,there would be something as July 20 1944, but in the Kremlin.
D This fighting would prevent the Soviets to mobilize
E The USSR would collapse.
The presence of 12 th Army was irrelevant for a German victory,.,as was the fighting in the Balkans . Besides,there is no relating between the outcome of the BoB and Marita,invasion of Yugoslavia and Mercury .
I forgot a point : Sealion would fail even without an intervention of the RN. And the LW was not strong enough to defeat Fighter Command (which always could withdraw to the North ) to stop counter-attacks by the Home Forces and to prevent the RN from intervening .

Roughly 30-40% of British manufacturing was/is located in the Southern portions of England, especially around London. This is actually an almost perfect mirror of the Ruhr in Germany and, as already stated, we saw how that worked out for Germany when the RAF began their campaign against it in 1943. Likewise, as I said earlier, beyond damaging the standing RAF/British Army and industrial infrastructure, having the Royal Navy fling itself ala Force X at the German landing force is a net benefit no matter how you slice it. Given Bismarck and Tirpitz are coming, and political pressure to prevent another landing attempt, this means inevitably the Royal Navy must reduce commitments elsewhere to effect force transfers to safeguard Great Britain itself.

All of the above has major strategic effects going forward. Nobody is going to Greece if the Italian Navy has superiority in the region, nor are forces going to Greece period if there is a serious risk of Egypt falling, and there would be. Yes, Britain was able to start sending reinforcements in September/October, but this was because by then it was clear Sealion was not coming and that the Luftwaffe had failed to gain the necessary air superiority for it to even be a viable threat. All of this will have political effects on the neutrals in their strategic thinking. Case in point here is the strong possibility of no Yugoslav coup and Turkey being amendable to German interests vis-a-vis the Anglo-Soviets.

Specifically as issues pertain to Barbarossa, the weather issues you cite were the heavy spring rains that caused severe flooding. This prevented a May start date for the invasion, but by June 10th said flood waters had receded and thus provided an opening for the attack to begin. What prevented such, however, was the equipment loss rates in the Balkans as well as the need to garrison the new conquests. This meant the 11th Army had to replace the 12th Army in AGS, which resulted in their delayed start and meant that AGS was unable to carry out the encirclements seen elsewhere in favor of a broad, frontal attack through Ukraine. Here, AGS would take Kiev on its own, decimating Soviet armies before Dnieper and overrun the Donets Basin. AGC, meanwhile, could advance on and take Moscow in September or October. The resulting loss in infrastructure and Soviet force capabilities would likely also doom Leningrad. All of this combined would be an non-survivable defeat for the USSR, ensuring a collapse in 1942.

All of this for the loss of 2-4 German divisions at maximum is a good trade off. Their own lacking in shipping capacity pretty much makes it impossible to lose more than that.