Arriving in England on temporary duty, Krick reported to General Ira Eaker at the Eighth Bomber Command. Eaker sent him to work with General Frederick L. Anderson, boss of the Eighth Air Force, whose headquarters were located underground outside London.

Krick soon learned what the problem was. The group's weatherman was simply giving the flight commanders bits of information -so many low clouds, so many high clouds, so many middle clouds- along the way to the target, over the target, and over the British Air Force bases. When the leader of a flight asked the weatherman for something more to the point, the weatherman hedged.

As a result, many missions were not getting off the ground. Approaching winter brought the promise of worse weather, and the Germans were gaining strength. General Anderson was getting restive. He was also becoming skeptical of the efficiency of his forecasting system. From time to time, as the weatherman continued to report targets socked in, he had sent a reconnaissance plane take pictures of the area at target time-only to learn that the area was clear. Thus, many chances to hit the enemy were being lost for want of better weather forecasting.

"I want you to see if you can't cut these forecasts finer," Anderson told Krick. "I'll slice them as thin as you want," Krick replied, "but you'll have a few aborted missions - we can't be perfect."

"We understand that," Anderson said. "Just tell us from your forecast - do we go or don't we. Better to abort a few missions than to keep sitting here on the ground while the krauts get stronger."

Krick replied, "Let's do it this way: You tell me what you need for the B-17 operations and what you need for the B-24s. [which could not fly as high as the B-17s]. Let me know what the specs are for the takeoff and return to base-route conditions for the fuel loads, target conditions-how many clouds you can stand, and the like. I'll put that blend into my mixer and come out with a yes or no-you can or you can't go."

Later, by the use of vertical glass plates spaced across a large map of Europe lying on a table, Krick depicted the weather in cross-section both vertically and horizontally, showing the pilots what lay ahead as well as below as they proceeded toward the target. Thus, applying an idea he had originated in Washington, Krick gave the airmen the "weather picture" in a literal sense, rather than relying on words alone, as was customary.

More bombs soon began falling on Europe. A target of special importance was a plant for making heavy water, operated by the Germans in connection with their atomic energy experiments. The plant lay hidden in one of the fjords of occupied Norway, nearly invisible except at high noon on a clear day.

The only time it was clear in Norway at that time of year- - November- was when there was a big high pressure area over the country, feeding cold air clouds into the British bases and causing icing problems to aircraft as they took off or returned through these clouds.

Krick found a day when the cost in lost planes would be relatively low, and the heavy water plant was blown out of commission.

General Anderson became increasingly impressed with Krick's abilities, as did others of the Air Force high command in England.

As the time neared for Krick's return to the United States, there was growing demand to keep him in Britain - or at least to get someone to take his place while he was home.

In the end, though, it was made clear that Krick himself was wanted back in England.

In Krick's pocket as he flew to Washington early in January, 1944, was a letter signed "Tooey" and stamped "Secret," from General Carl Spaatz, commander of the newly formed United States Strategic Air Forces in Europe, to his chief back home, General Arnold.

General Spaatz wanted something "absolutely essential" which the Strategic Air Forces had not had. This was a "coordinated weather forecasting system," including long-range forecasting. Except for Krick's work for the Eighth Bomber Command, Spaatz wrote, "there is no consistent long-range forecasting in this theater."

Spaatz intended to make up this lack, but he would need help since time was short. "The first step in this action has already been accomplished by the agreement of AAF Headquarters to release Colonel Krick for assignment," Spaatz wrote to Arnold. He mentioned a cable dated January 5, 1944.

He asked Arnold to help Krick get releases and orders for about ten men from the Weather Information Branch and have them as well as Krick "ordered over here at once on the highest priority." He added that Krick was expected to "be of invaluable assistance in forthcoming operations."

The operations General Spaatz had in mind were to rain bombs on Europe until Hitler had as little left as possible to hit back with when the Allies invaded France. The problem was to find suitable weather to carry out the bombing campaign code-named "Argument." The winter months over Europe historically were cloudy, hiding the targets and giving the enemy time to recover after each blow. The need was for a run of several good bombing days in a row.

With the hand-picked crew of forecasters General Spaatz wanted, Krick returned to England to find such a sequence of good bombing days. He was unaware that while he was in Washington his old nemesis. Dr. Rossby, as consultant to the War Department, had shown up in Britain and tried to block Krick's program, telling Spaatz that Krick had no scientific standing and would not be acceptable to the British, with whom the Americans had to co-ordinate operations.

Spaatz let it all go out the other ear and said nothing of the incident to Krick until the spring of 1944 after the air power he commanded, operating under Krick's weather forecasts, had gained superiority over the German Air Force and made rubble of key enemy targets.

The magic combination of days that made this possible took some time to discover. Searching between their briefings of bomber crews, Krick and Colonel Ben Holzman, who had earned his master's degree from Krick at CalTech, took turns at a grueling routine of thirty-six hours on and twelve hours off.

By early February, with D-Day coming up in June, there was still no such run of bombing weather in sight. Then Krick thought he saw what was needed taking shape: three days of clear weather. A high pressure area over Siberia was pushing westward across Germany, clearing out all cloudiness before it, but with snow along the forward edge. There had been a similar situation in 1928, as spotted by Krick and Hoizman in searching their forty-year archive of classified hemispheric maps worked up earlier in the joint Cal-Tech - New York University map project.

On February 17 Krick briefed General Spaatz and his deputy commander for operations. General Anderson, on what was coming. "You can pull the string on the twentieth," Krick said. "There'll be three straight days of perfect weather-maybe a little more." General Spaatz ordered the decks cleared for action - although, with the Germans at full defensive strength, he expected to lose as many as 250 planes on this first strike.

Krick disagreed. "The weather will be so lousy even when you take off, the fighters in Germany won't even be able to find you," he said.

Late on the night of February 19, with only hours to go, weathermen from the Eighth Air Force, now commanded by General James H. Doolittle, hero of the raid on Tokyo early in the war, reported it was still snowing at Leipzig, the main target. Doolittle canceled the strike.

"Sure, it will be snowing," pointed out Colonel Hoizman, who had the duty that night, "but by the time you get there it will be clear."

General Spaatz thereupon countermanded the cancellation and rescheduled the takeoff for the early morning of February 20. Sure enough, when the bombers arrived over Germany it was snowing, and it kept snowing to within ten miles of Leipzig, just as forecast. Then the storm cleared, and Leipzig was left in flames. Hardly any fighters came up, the raiders not having been expected.

This was only a detail in the broader picture of what happened that morning to smash the Nazi war machine. All told, 11,000 men aboard 1,028 heavy bombers and 832 fighter planes were in the air over Germany, hitting key production centers. While General Doolittle and his Eighth Air Force struck from England, Major General Nathan F. Twining, commanding the Fifteenth Air Force, struck from Italy.

It was a good day. All but 25 Allied bombers and 4 fighters made it back to base. The Germans, swarming aloft to beat back the attackers where they were not caught unaware, as at Leipzig, lost 153 fighters.

Years later, as he walked one day in the Pentagon with his wife, Marie, Krick would run into General Anderson, his old operations chief in England. Anderson threw his arms around Krick and said, "Doc, do you remember the day we won the war?" He meant that pivotal February day in 1944 when Leipzig was shattered, starting to turn the war around for the Allies.

For four more days the attack on Germany continued. When it finally ended, as bad weather returned, the German Air Force was badly crippled and never would recover its previous strength.