A Veterans Day Homage To The Most Important Weather Forecast In History

2019-11-11 06:17:42.000 – Jay Broccolo, Weather Observer and Meteorologist


Veterans Day is a time for us all to pay our respects to those who have served this country with bravery and honor. Our veterans should be remembered every day for what they have sacrificed for the rest of us. I currently have a couple of family members serving in the armed forces and am extremely proud of both of them. I have friends that serve in different branches with many of them serving in the National Guard. I’m sure each of us can think about a family member/s or friend/s who deserve recognition. For my Eagle Scout project, I created a documentary of WWII veterans from my hometown and gave it to the local school system and library. I was even fortunate enough to be able to interview a couple of the Doolittle Raiders, whom were involved in the first air operations to strike Japan on April 18th, 1942. At the time, I had no idea I was going to enter the field of Atmospheric Science, but it was fascinating that a number of the veterans I interviewed with talked about the weather forecasts involved with their missions. This brings me to today’s blog post where I would like to share how a weather forecast proved to be a monumental factor in the Allied forces success in WWII. 

Arguably, the most important weather forecast ever made was the forecast made for the invasion of Normandy on June 6th, 1944, otherwise known as D-Day. A little known fact about D-Day is that it was originally scheduled for June 5th. Operation Overlord, the codename for the Battle of Normandy and Operation Neptune, the actual Normandy landings involved more than 160,000 Allied troops. They stormed the 50 mile stretch of fortified beaches and their bravery and courage was the start to the turning point of WWII.   The Allied forces, under General Dwight D. Eisenhower, were stationed In Portsmouth, England or heading towards France preparing for the amphibious invasion of Normandy for the morning of June 5th. It took years of planning to organize the operation. They wanted to have a bright full moon and land on the beaches during low tide. They decided on a span of time in early June between the 5th and 7th based on historical trends, but on May 29th, weather observations taken in Newfoundland indicated changing conditions that would potentially arrive on the proposed selected date of the 5th. At this point, it was up to a team of 6 meteorologists, two from the U.S., two from the Royal Air Force (RAF), and another two from the U.K. Met Office, headed by RAF meteorologist Captain James Stagg.

A low-pressure system was moving east, followed by a secondary Low. High winds and seas from the storms would jeopardize the operation. Planes would be unable to fly and the boats carrying the troops could potentially capsize. At the time, there were no satellites, no radars, and obviously no computers. Meteorological data was far sparser compared to today. It would take an entire day or so just to create a synoptic map for a 6 hour period, which today is completed in hours using computer models and is far more detailed. At any rate, American weather studies and meteorology was still in its infancy. America had the advantage to be able to track storm all the way from the west coast to the east coast. The U.K. was less fortunate in that regard. The American forecasters forecasted based off of historical trends whereas the English meteorologists relied heavily on the observational data and used historical trends to justify their forecasts. 

By June 3rd, all six meteorologists knew that the 5th would involve unfavorable conditions for a landing. Between the 3rd leading up to hours before the original time of deployment on the 5th, some disagreement in the forecasts rose. The American forecasters believed that the storm was only going to get worse and thought that an earlier deployment would be better. The English meteorologists believed that there would a break between the two systems. After, much debate and reluctance, Captain Stagg persuaded General Eisenhower to postpone the invasion 24 hours. What is most interesting to me is the process of how they came to this decision and in my mind, it is fortunate that they were situated in a geographical position that gave them a massive advantage. Weather stations on the west coast of Ireland proved to be of immense value. A weather station at a post office at Blacksod Point helped detect the lull between the two systems. With this new data, all six meteorologists reluctantly agreed. As this happened on the 4th, while Portsmouth was battered by the arriving Low, Stagg relayed this information to Eisenhower, forever changing the course of history. 

On the morning of the 5th, winds were blowing around 30 mph, with rough seas. These conditions persisted through the day and into the morning of the 6th. The seas were still rough with increased wind speeds along with cloud cover. The rough seas caused boats carrying troops to capsize and mortar shells to miss their intended destinations. High winds and cloud cover cause paratroopers to land miles away as well as bombers to also miss their targets. Later that day, the skies did clear. Stagg’s forecast validated and even though the Allied forces suffered extreme losses, the beaches of Normandy were secured and the Germans abated the region. The element of surprise was heightened by the forecasting on the other side of the channel.

While the Allied forces were no doubt anxiously forecasting for the invasion and making crucial decisions, the German forecasters were not privy to the same data that the Allies were lucky to have and used less sophisticated methods. They still forecasted stormy conditions, the Luftwaffe’s meteorologist forecasted that rough seas and adverse conditions would persist through mid-June. Because of their forecast, German forces believed that Allied forces would not occur. Many commanders left their posts along the coast to attend nearby war games. They technically weren’t wrong either. Unfavorable conditions persisted for the first half of June, but what the Germans missed was the lull between the two systems that the Allied forces had picked up on, largely due to their more detailed forecasting techniques and the information that the Blacksod Point Weather Station recorded. Turns out that June of 1944 was one of the windiest months in the 20th century. During the actual invasion, the weather prevented German forces to reinforce their lines, securing bridges and roadways. It also left them with few options for egress.

It always amazes me just how fragile human history is.  Years later, a book written by John Ross “The Forecast for D-Day: And the Weatherman behind Ike’s Greatest Gamble”, describes a conversation between President-Elect John F. Kennedy and then President Eisenhower why the Normandy invasion had been so successful. Eisenhower’s response was “Because we had better meteorologists than the Germans!”




The Forecast for D-Day: And the Weatherman behind Ike’s Greatest Gamble” – John Ross




Jay Broccolo, Weather Observer and Meteorologist

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