Clear skies over the Ardennes

On the morning of 23 December 1944, after a week of fog, low cloud and freezing drizzle, the sun came out over the Ardennes. Cold, dry air from an extensive high-pressure system, which American meteorologists called the “Russian high”, flowed over western Europe from the north-east. The temperature fell below freezing, the ground froze hard, and the sky was clear to the horizon. For the soldiers who had been fighting since 16 December this meant one thing above all: Allied aircraft, which had barely taken off during the first week of the German offensive, could at last return to the battlefield.

The clear weather is sometimes described as “the only factor Hitler feared”. That is a simplification. The German planners did indeed make the date of the attack depend on a forecast of bad weather, but Adolf Hitler and his commanders also had to reckon with a shortage of fuel, the rapid movement of Allied reserves and the resistance of American units – and these factors halted the offensive just as much as air power did. By the time the skies cleared, the attack was already several days behind schedule.

An offensive under cover of cloud

The Wacht am Rhein plan assumed that three German armies – Sepp Dietrich’s Sixth SS Panzer Army, Hasso von Manteuffel’s Fifth Panzer Army and the Seventh Army – would pass through the Ardennes within a few days, cross the Meuse and advance on Antwerp. But the Wehrmacht no longer had any means of defending itself against Allied air power: after years of losses the Luftwaffe was too weak to give cover to the armoured columns, and the summer of 1944 in Normandy had shown what fighter-bombers operating by day did to German divisions. It was therefore assumed from the outset that the attack would take place during a period of prolonged overcast that would keep Allied aircraft grounded. The date was postponed several times while the planners waited for a suitable forecast.

That condition was met. From 16 to 22 December fog and low cloud hung over the Ardennes and over the airfields in England, Belgium and France. American reconnaissance aircraft had failed to spot the concentration of German troops before the offensive, and in the first days of the battle tactical aircraft could fly only occasional sorties during brief clear spells. German columns moved along the roads by day, something they could not have afforded in France in the summer.

Even so, within the first week the offensive had begun to diverge from the plan. In the north the Sixth SS Panzer Army got stuck in front of the Elsenborn ridge, where the American 2nd and 99th Infantry Divisions halted Dietrich’s attack. Joachim Peiper’s battle group, which had left the crime near Malmedy in its wake, was cut off in the valley of the Amblève. St. Vith, a key road junction, held out until 21 December, and Bastogne, surrounded by the Germans, beat off one attack after another and on 22 December rejected a demand to surrender with Brigadier General Anthony McAuliffe’s famous “Nuts!”. The Fifth Panzer Army advanced furthest west, but its spearheads, too, were beginning to run short of fuel.

Aircraft over the roads of the Ardennes

On the morning of 23 December Allied tactical air forces took off in full strength. Over the northern part of the front operated Major General Elwood Quesada’s IX Tactical Air Command, working with the American First Army; over the southern part, Brigadier General Otto Weyland’s XIX Tactical Air Command, supporting Lieutenant General George Patton’s Third Army. Both commands belonged to Lieutenant General Hoyt Vandenberg’s Ninth Air Force. On the British side the fighter-bombers of the RAF’s Second Tactical Air Force went into action, including rocket-armed Hawker Typhoons.

The main striking force consisted of Republic P-47 Thunderbolt and Lockheed P-38 Lightning fighter-bombers. They attacked columns of lorries and tanks on the narrow, snow-covered roads, bridges, villages turned into strongpoints, and German artillery positions. Vehicles stood out clearly against the clean snow, and the crossings of the river valleys – the Ourthe, the Amblève, the Sûre – created natural bottlenecks in which the columns became easy targets. German soldiers and commanders, in their accounts of those days, stressed that movement by day practically ceased and that supplies had to be moved at night.

Further east the Martin B-26 Marauder and Douglas A-26 Invader medium bombers of IX Bomber Command were at work. Their targets were the bridges and the rail and road junctions in the Eifel and on the west bank of the Rhine through which the offensive’s supplies flowed. On 23 December the Marauder formations met strong opposition from German fighters and flak and suffered heavy losses that day – the Luftwaffe, though weakened, could still concentrate several hundred aircraft over the Ardennes. Fierce air battles were fought over the front in the days that followed.

The strategic bombers joined the attacks on the rear areas. On 24 December the Eighth Air Force sent more than 2,000 heavy bombers over Germany – the largest single raid by that formation in the whole war – directing them mainly at airfields and communications centres in the western Reich. The mission leader, Brigadier General Frederick Castle, was killed when his B-17 was shot down and crashed in Belgium; he was posthumously awarded the Medal of Honor. In those same days RAF Bomber Command attacked railway junctions in the Rhineland, including Trier, whose centre was largely destroyed at the time.

Supply from the air for Bastogne

The aircraft most eagerly awaited were those over Bastogne. The encircled town, defended by the 101st Airborne Division, Combat Command B of the 10th Armored Division and smaller units, including the African-American 969th Field Artillery Battalion, was on the verge of running out of supplies. On 22 December artillery ammunition was limited to 10 rounds per gun per day, dressings were in short supply, and many wounded lay in cellars and garages without surgical care, because the division’s field hospital had fallen into German hands in the first days of the battle.

On the morning of 23 December two teams of pathfinders – paratroopers whose job was to guide in the aircraft – jumped over the town from two planes and set up radio beacons for the incoming transports. Soon afterwards successive waves of Douglas C-47 Skytrain aircraft of IX Troop Carrier Command began arriving over the drop zone. According to figures compiled by the American glider pilots’ association, of the 264 C-47s sent out that day 253 reached the drop zone, dropping about 334 tons of ammunition, food and medical supplies. The aircraft flew low and in separate groups, so several were shot down by German flak deployed around the pocket.

The drops were repeated on 24 December and, after a weather-enforced pause on Christmas Day, on 26 and 27 December, when according to the same figures some 290 aircraft flew over the town with 169 tons of cargo. On 26 December the first glider landed at Bastogne carrying a volunteer team of surgeons and medical orderlies, who immediately began operating on the wounded; further gliders brought in ammunition and fuel. Estimates of the total supplies delivered to the defenders between 23 and 27 December vary from source to source, but they amounted to several hundred tons in all. This enabled the defenders to beat off a powerful German attack on Christmas Day, while fighter-bombers of XIX Tactical Air Command struck units forming up for the assault just in front of the paratroopers’ lines.

Fuel and the Meuse

The other side of the picture was the German rear. The offensive suffered from a shortage of fuel from the very start – the panzer divisions had set out with stocks meant to last as far as the Meuse, on the assumption that American dumps would be captured along the way. That did not happen: the Americans managed to remove or burn the largest depots, including the one near Stavelot. Now air attacks on roads and rail junctions hampered the delivery of what fuel remained. Supply columns waited in the forests for nightfall, and tanks came to a halt with empty tanks.

The Fifth Panzer Army’s spearhead felt this most acutely. The Wehrmacht’s 2nd Panzer Division, advancing westwards past besieged Bastogne, reached the woods around Foy-Notre-Dame (PL) on 23 December, only a few kilometres from the Meuse at Dinant, and on 24 December its units and the neighbouring Panzer Lehr Division reached the area around Celles. This was the furthest point the German offensive attained. The bridge at Dinant was defended by British units of the 29th Armoured Brigade, and the forward German battle groups were stranded without fuel. On 24–26 December they were attacked by Major General Ernest Harmon’s American 2nd Armored Division, supported by British tanks and fighter-bombers; around Celles several dozen German tanks and hundreds of vehicles were destroyed or captured. In the north Peiper’s battle group, surrounded in La Gleize, abandoned its tanks and heavy equipment on the night of 23/24 December and broke out on foot to its own lines – of a group that had numbered some 4,800 men at the start of the offensive, about 800 were left in La Gleize, and most of them managed to escape the encirclement.

A prayer for weather

The improvement in the weather is linked to one of the most frequently repeated anecdotes of the battle. In early December, before the German offensive, when the Third Army was fighting in rain and mud in Lorraine, Patton asked the army’s chief chaplain, Chaplain (Colonel) James O’Neill, to write a prayer for good weather for fighting. According to O’Neill’s account, the text was printed on cards bearing the commander’s Christmas greetings and some 250,000 copies were handed out to the soldiers of the Third Army. When the skies cleared on 23 December, Patton – as the chaplain recalled – was convinced the prayer had worked and decorated O’Neill with the Bronze Star. The story, recounted by the chaplain himself, became part of the general’s legend; for historians it is above all evidence of how heavily both sides made their plans depend on the weather.

Significance

Clear skies did not in themselves decide the fate of the offensive – the German attack had already been halted in the north, delayed at St. Vith and tied down at Bastogne, and the panzer divisions were short of fuel even before 23 December. But from that day on the Wehrmacht lost its most important asset: freedom of movement by day. Supply from the air enabled the defenders of Bastogne to hold out until 26 December, when units of Patton’s Third Army broke through to the town, and air attacks on roads and rail junctions deepened the fuel crisis that immobilised the German spearheads near the Meuse.

The good weather lasted only a few days; at the end of December and in January snow fell over the Ardennes again and the clouds returned. On the evening of 24 December Manteuffel proposed halting the attack and withdrawing, but Hitler refused. The Luftwaffe responded on 1 January 1945 with Operation Bodenplatte – a massed attack on Allied airfields in Belgium, the Netherlands and France, which destroyed many aircraft on the ground but cost the Germans several hundred aircraft and pilots who could no longer be replaced. When in January 1945 the Americans and British went over to the counter-offensive and on 25 January eliminated the German salient in the Ardennes, air superiority was once again one of the key factors in their victory.