I never managed to "bring the House down" myself, but once an unfortunate Met man, having ended his spiel, chanced his arm and asked "Any Questions ?"
One cold winter day at RAF Brawdy, with the cloud brushing the chimney on the 'biscuit factory*' or US NAVFAC as it was properly named, we were all assembled in the cinema for the morning met brief...
The Met man's slides were ready on the OHP, when the Stn Cdr, a cheery fighter pilot, entered. "Morning, Met!", he began, "have some actual!". At which a threw a snowball at the Met man, which landed on the slides - which had been drawn with water-based lumocolor pens. The resulting mess did indeed bring the house down!
On another occasion, the Met man was asked if there was any risk of the rain turning to snow. "No chance", he confidently replied. The next question (from someone who, unlike the Met man, could see out of the window) was "What is the correct meteorological term for that fluffy white stuff which is falling out of the clouds?"
* so named because it was commanded by a Captain Jacobs. A sneaky-beaky place, about whose purpose we weren't supposed to know - it was actually a (then) highly secret SOSUS submarine accoustic tracking facility.