At the beginning of September the Wehrmacht could look on the situation in France and Italy with some degree of satisfaction.  Although Allied invasion of northern France had not been stopped it has been contained in a roughly dog bone shaped lodgement stretching from eastern Normandy to the Pas de Calais.  But disquiet was growing at OKW. Intelligence reports indicated the Allies now had a massive force ashore and if the Fall rains didn’t come soon the next blow might be too much to bear.  The German commanders in the west were also uncomfortably aware that their ability to hold the line had been made possible by Hitler’s emergency declaration that has diverted thousands of replacements to the western army, but soon the flow of replacements would have to shift back to the East.

Throughout September strong American forces threw repeated attacks against the eastern end of the German line slowly bleeding the infantry, but not outrunning the Germans ability to replace the losses and plug the holes as they appeared.  Some more ground was lost, but the situation remained stable.  An American attempt to punch a whole in the German center failed to make any headway.
The situation at the eastern end of the pocket decayed steadily throughout September.  The British slogged through the bocage clear the region around Caen and at the end of September the Germans decided to withdraw all their mobile forces from the Cotentin Peninsula before they could be trapped there.  One British spearhead was less than forty miles from the west side of the Peninsula. Just to the south on the edge of hedgerow country the British managed to punch through one German infantry corps and began to push through the whole.  By the end of the month a full-scale crisis was apparent.  The French 2ns Armored division and supporting units had rolled into Chartres and a British armored car battalion supported by airlifted American paratroops seized a key town on the railway approaching Paris from the southwest.
In the meeting with Hitler that followed the field commanders may have deliberately overstated the strength of the Allied force heading towards Paris, but it was clear to them the forces west of Paris needed to start moving now, or they could all be lost.  Hitler gave in and authorized the evacuation of western and southern France.  Within hours the commanders were issuing movement orders fearing that any delay might lead to Hitler changing his mind.  Long  lines of troops staggered eastward, grateful that Allied airpower was directed at pounding the front lines instead of stopping their withdrawal.
Finally, at the beginning of October the situation began to deteriorate much more quickly.  The British endeavored to turn the gap into a gaping hole.  They launched four attacks of varying success.  The French 2nd armored division continued its push towards Paris, pushing back an odd blocking force of German artillery and assault guns supported by VIchy Militia.  The blocking force gave ground but didn’t crack with French getting almost too within sight of their occupied capital.  It was now possible to hear the sound of guns in the Paris suburbs.  Just to the north, the British and Canadians began to roll up the German line pushing back a static division and virtually surrounding the reinforced panzer division that was holding the western Flank of the still intact portion of the German line.  After heavy fighting the hard fighting panzers and their supporting units were trapped and destroyed.  Another assault by British armor against the German infantry retreating from the bocage. was held off by a desperately reisting infantry corps..
At the American end of the lodgement two strong attacks punched holes in the German line. A mixed corps south of Calais was routed with two infantry divisions being reduced to cadres and the U.S. 4th corps with massive air support smashed a corps on the south-central section of the German line open9ing the Seine River Valley towards Paris.  The fall rains can’t come soon enough for the retreating Germans.
In Italy the fighting seemed to continue along a set pattern.  The Allies would aim two strong  blows at the German lines at once, one would succeed in taking a German position and the other attack would stall out.  The Germans would lose some troops and pull back to their next line.  The Allies would trundle forward and do the whole thing again.