Operator Wintergewitter, or Operation Winter Storm, was an attempt on the World War II Eastern front mounted by the German 4th Panzer Army to relieve the German 6th Army, trapped at Stalingrad. It commenced on 12 December 1942 and was able to advance just halfway to its objective before a Soviet outflanking move further to the north forced the relief force to break off and withdraw, dooming the 6th Army to defeat and capture.

The surrounding of the German 6th Army by Soviet forces in Operation Uranus had pushed the main body of the Wehrmacht's Army Group South back by sixty to eighty miles. While 4th Panzer Army's XLVIII Panzer Corps established a line on the Chir River , its southern wing had been shattered and only skeleton forces managed to prevent the Soviet 51st Army from breaking into Kotelnikovo , a railhead eighty miles south of Stalingrad, by turning them away at Pakhlebin a couple of miles to the north of that town. Therefore any relief attempt depended on gathering panzer forces from elsewhere. Freshest of the troops chosen was the 6th Panzer Division , then refitting in France after nine months on the Eastern Front. From Army Group Centre came 17th Panzer Division from the Zhizdra front, and from Army Group A in the Caucasus came the 23rd Panzer Division , recovering from the narrowly averted disaster before Orzhonikidze. These three divisions constituted LVII Panzer Corps .

Where to launch the relief attempt was key. The bridgehead over the Don at Verkhne-Chirskaya was physically closest to Stalingrad, but the Russians saw this coming and made sure this bridgehead was knocked out before the anticipated German reinforcements could be assembled. In any case the Don was insufficiently frozen for troops to cross safely — the weather in late November and early December 1942 ranged intermittently from snow to heavy rain.

Instead LVII Panzer Corps was assembled at Kotelnikovo. With 6th Panzer in the middle, 17th Panzer to its left and 23rd Panzer to its right, plus the remnants of the Romanian 4th Army holding the thinly-manned flanks facing the Kalmyk steppes, the offensive began on 12 December. Two rivers lay in the force's path — the Aksai River and the Myshkova River . The force made good progress at first, reaching and crossing the Aksai by the end of the first day but being drawn into heavy fighting at the 8th of March collective farm at Verkhne-Kumsky, and around the railway ganger's hut immediately to the north of the Aksai's banks. The relief force ground towards the Myshkova, using up precious time, but could not cross. In Stalingrad itself, General Friedrich Paulus dithered as to whether to instruct his exhausted and freezing troops to break out to the south, where they would join with Hoth's panzer force at Abganerovo and together withdraw to Kotelnikovo. Without a direct order from Adolf Hitler, he could not make the decision. Obsessed with not withdrawing from where his forces had set foot, Hitler did not give that order, and Paulus stayed put. Whether his fuel- and food-lacking forces could have got themselves out of Stalingrad at all by then is open to question.

As the relief force made its thrust, Soviet Marshal Georgy Zhukov hit the Axis front line further to the north. The Italian 8th Army on the middle Don was suffering the same effects of the cold weather, and gave little resistance to the T-34s that now came crashing through their positions on 16 December. Having brushed aside the Italian contribution to the war on communism, Zhukov added insult to injury by making for Tatskinskaya , the air base closest to Stalingrad and from which the Luftwaffe had been embarking on the hopelessly ambitious task of supplying half a million fighting men in uncertain weather. On Christmas Day the Soviet tanks drove through snowstorms to the airfield and roamed about for hours, blowing away the German transport planes at their leisure.

Seeing that this force was swinging to the left in order to come down behind the German relief army, Erich von Manstein had to detach the 6th Panzer Division from the Myshkova and rushed it to the Italians' aid, saving the position there for the moment but dooming the relief attempt. Accordingly, the Soviet 51st Army then attacked the relief force anew, driving it back to and beyond Kotelnikovo by 29 December and now threatening both Rostov and the entire Army Group A of 400,000 men still bottled up on the Terek River in the Caucasus. Hitler had to make the hard decision to pull this force out altogether, consigning Stalingrad to its fate.