The Battle of Britain day an RAF radar fitter from Wisbech upset his superiors by predicting the weather

William Purkis.

William Purkis. - Credit: Archant

Today meteorologists forecast the weather using radar, but this was not always the case. In 1947, a Wisbech man attempted to convince the Meteorology Office, who until then steadfastly relied on more primitive methods, to embrace the future.

William Purkis.

William Purkis. - Credit: Archant

WILLIAM PURKIS was conscripted into the RAF in 1946, a year after the end of the Second World War. He was a radar fitter at RAF Stradishall. His field of expertise was H2S, the first airborne, ground scanning radar system. It was developed in Britain during the Second World War for the Royal Air Force and used in various RAF bomber aircraft.

On September 15 1947, to commemorate Battle of Britain Day, RAF Stradishall opened its doors to visitors, one of whom took a particular interest in William’s H2S gear.

The visitor asked him what a mark on the screen was. William explained it was a cloud and using the image predicted it would rain at 3pm that afternoon.

His prediction proved unerringly accurate. It also made the Meterology Office look a bit foolish, and landed him in a spot of bother with his superiors. This is his story in his words:

I was on duty at RAF Stradishall for the occasion in 1947, having been conscripted into the service the year before. Fortunately, I had been able to secure a place at the radio school and after 12 months I was a fully paid up radar fitter, a cream trade for one in the lower ranks.

My job was to maintain the airborne radar equipment aboard our four squadrons of Lancaster bombers. Each aircraft was fitted with navigation, altitude, guided-landing and blind-bombing radar and as it had to be checked regularly there was always plenty to do.

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For Battle of Britain Day our section hut was cleaned and polished more than usual and we had the test rigs functioning to show anyone who was interested how the aircrews used them as flying aids. My particular baby was H2S, the blind-bombing equipment.

H2S consisted of a number of interconnected boxes, an aerial (rotating scanner) and a display (Plan Position Indicator).

In use, the scanner was fitted under the aircraft to transmit and receive the return signals reflected from the ground below.

These were displayed as constantly refreshed black and white images on the screen; not much detail, but rivers, coastlines, and towns would show up with enough geographical accuracy to pinpoint the position of the aircraft when finding bombing targets below.

For testing purposes in our hut the scanner sat on the bench facing upwards scanning the usually empty sky; the connected PPI simply displayed some clutter at the centre of the screen that came from reflections off the four large aircraft hangers on site.

Nevertheless this was all that we needed to check that the gear was working properly.

Open to the public on the day we soon had visitors; ours was one of the more interesting shows and plenty of people came to our corner of the airfield.

One man in particular quizzed me at length about the gear. What’s that, he said, pointing to a patch on the PPI.

I said it was a rain cloud; rain was always detected and it showed up on the screen, and by using marker rings on the display I was able to tell him how far distant the rain was.

We continued to talk, and after a time I said that while we’ve been talking the rain has come closer by a mile and at this rate it will arrive here by three o’clock. We said our goodbyes and the man went on his way.

At one minute to three the first rain drops were splashing on the windows; at one minute past it was raining steadily, and at thirty minutes past I was summonsed into the office.

Inside, talking to Flt. Lt. Morris, our section head, was another officer who looked less pleased with himself. “How dare I tell a civilian that it was going to rain at three o’clock?” I didn’t know how to answer his exclamation, but I didn’t have to.

It soon became clear that after leaving me my chatty visitor had gone straight to the station meteorology section and told the officer commanding about the rain at 3pm.

He said there might be rain about but he didn’t know of any, and it certainly wasn’t likely to rain that afternoon; what, after all, did the radar boys know about the weather.

My chatty visitor stayed on until the rain began to fall; it was 3pm and, triumphantly, he said to the met officer, “there, I told you so!”.

Overriding authority having been shot to pieces by a civilian and now overcome with indignation I became the target of his ire.

After the unequal rank confrontation in the office, and when he had cooled down a little, I had to show him how I had watched the weather develop on screen and could, with a fair degree of accuracy, know what was to happen.

The Meteorology Department, that still predicted the weather with a piece of damp string, went away somewhat deflated.

Nowadays all weather forecasting is done by radar observation, but many years were to pass before the Meteorology Office were prepared to accept it, so slowly does the establishment change its ways.


On September 15 1940 - now known as Battle of Britain Day - the Luftwaffe launched two huge bombing raids on London. Believing that the RAF was close to breaking point, the attacks were a repeat of their monumental and devastating attack eight days before.

During both of the raids that day, the RAF managed to scatter many of the German bomber formations.

This meant that when the surviving bombers did drop their loads, they fell over a wide area and were less harmful. Thousands of Londoners stood in the streets below watching the battle rage over their heads.

The RAF shot down 61 planes, the highest losses the Luftwaffe had suffered for over a month. The RAF lost 31 planes.

Although fighting continued in the air for several more weeks, and British cities were bombed sporadically for the rest of the war, German tactics to achieve air superiority ahead of an invasion failed.