To backup what i have said
"Army Group South pushed down from the Dniepr to the Sea of Azov
coast, also advancing through Kharkov, Kursk and Stalino, and on 21
November took Rostov, the gateway to the Caucasus. However, the
German lines were over-extended and the Soviet defenders
counterattacked the 1st Panzer Army's spearhead from the north,
forcing them to pull out of the city and behind the Mius river; the
first proper German withdrawal of the war.
Just as Operation Typhoon got going, the Russian weather struck.
For the second half of October it rained solidly, turning what few
roads there were into endless mud that trapped German vehicles,
horses and men alike. With 100 miles still to go to Moscow, there
was worse to come when the temperature plunged and snow started
following. The vehicles could move again, but the men could not,
freezing with no winter clothing. The German leadership, expecting
the campaign to be over in a few months, had not equipped their
armies for winter fighting.
One last lunge on 15 November saw the Germans attempting to throw a
ring around Moscow. On 27 November 4th Panzer Army got within 19
miles of the Kremlin when it reached the last tramstop of the
Moscow line at Khimki, while 2nd Panzer Army, try as it might,
could not take Tula, the last Russian city that stood in its way of
the capital. Furious rows marked the difference in opinion between
Hitler, who insisted that the drive towards Moscow could not be
halted, and his generals, whose troops were completely exhausted in
the murderous cold. As the Fuhrer started sacking those commanders
who opposed him, it was at this point that the Soviets struck back
for the first time."
The power of Russian Winter . Taken from wiki
