"The Ryman method involves describing every weather situation in figures and making a mathematically informed estimate of how it could develop", I said. "He divides the atmosphere into three-dimensional parcels of air and assigns numerical values to each aspect of the weather within them. Then he uses maths to see where things may go."

...

"The truth is, Meadows, he's not an easy man but he is a brilliant one and the British meteorological community has felt the lack of him keenly. Now we come to the nub of the thing. Are you acquainted with the so-called Ryman number?"

I was coming to the limit of my knowledge. "Only in the most basic sense, sir," I admitted. "It explains the dynamic relationship between the two type of energy, kinetic and potential, that change the weather."

Sir Peter nodded. He did not seem surprised. "No one has got much beyond the basics. That is what I' am sending you to Scotland for. Though I once used some of his work, I myself know only a little about this side of things."

"Why do you need to...? If I may ask...?"

"The Ryman number is of enormous significance because it defines the amount of turbulence in a given situation. ... The government wants to use this number for a particular operation. Airborne and amphibious and enormous in scale. The long-expected invasion across the Channel into mainland Europe. We think Ryan himself is the only man alive who really understand how a range of values of his number might be practically applied - around a specific geographical area and over a particular time window - but he has not responded to my letters."

I spent the second night in the cot-house, as I would many over the forthcoming four months, doing calculations - sometimes in my head, sometimes with a wooden slide-rule, notched and ink-stained, which I still possess. Squeezing precision out of continuous domains in a mustering tumult of differential calculus - such was my life in that strange time.

Lying on the bed doing calculus. Sitting on the crapper doing calculus. Shaving doing calculus. Doing calculus while listening to the radio, hearing what was going on in the war or, for preference, some classical music. Doing calculus while eating. Doing calculus while squeezing the toothpaste tube.

"He has a messy little beard, wears specs. Looks a bit peculiar. Holes in his suit jacket." She giggled. "You better watch out or that's what you will become."

"Why?" I asked, affronted.

"All you scientists end up that way."

"What do you mean?"

"You have no style. All you think about are your equations."

"Ah," I said, rising to the challenge. "That that is just it, don't you see? The style is in the equations. Some people write ugly proofs, others do it with panache. I like to think mine are as beautiful as, as -- well, anything!"

I watched her face become aghast. "Anything? Anything is not beautiful. Only special things are beautiful."

I felt embarrassed at my inability to express myself. "All right, Miss, if you say so. But one day I'll show you some of those equations and you will see what I mean."

The book missed the point that the final weather decision was made on foot of the meteorological report from Belmullet in the North West of Ireland which showed an approaching high and tilted the balance to D day being on June 6th. This is well documentated and indeed is celebrated in Belmullet annually. It showed there was a short window of opportunity which would be in the English Channel area on the 6th after the poor weather of the 5th. This was truly the deciding weather report.

I am someone who would probably not even understand a Math for Dummies book so I was happy with the limited amount of real math within the book. As was mentioned above, the author definitely emphasized that math played a major role in deciphering weather patterns. This book definitely increased my interest in learning more about the role of math in evaluating what we non-math people think of as everyday mundane topics.

Regarding the characters in the book, I looked some of them up on the internet: Kricks, Stagg and Petterssen and perhaps others on the various teams were for real.