I have noticed for many years that weather patterns often last about a fortnight. This reminds me of the Biblical story of “forty” days and “forty” nights of rain. If you didn’t know that “fortnight” meant fourteen, you would probably assume it meant forty. Perhaps a mistranslation somewhere down the line.
Recently I have been observing patterns around the Moon, and I can now see that the Moon cycle of approx 28 days (sometimes 27 or 29, or 30 depending on what mood it is in), can be split into two halves, two fortnights. The weather patterns match the moon cycle.
One fortnight is the Daytime, or New Moon, fortnight, when the Moon is leading up to the New Moon for about a week, then another week as it moves away. All this time, it is near the Sun, aligned with the Sun for New Moon, and is in constant daylight. We don’t really notice it much because the Sun is much more obvious in the day.
The other fortnight is the Nighttime, or Full Moon, fortnight, when the Moon is always in the night sky, a week either side of the Full Moon. At Full Moon, the Moon is aligned with the Sun, but on the other side of the Earth from it. We notice the Moon more in the Nighttime fortnight because there is no Sun around to upstage it. And this is when the Moon seems to have the most control.
Recently we have had 3 weeks of rain, and it looks like a fourth week until the next possible change point. Two fortnights of rain, back to back. Occasionally there is a day that is slightly different, but the general pattern is much the same for a fortnight. Sometimes it is a fortnight of warm sunny weather. Or a fortnight of snow and ice. I can only speak for English weather as that is where I live.
The Full Moon behaves like a fridge, working against the Sun. It gets its energy from the Sun, and turns that into cold to blast at the planet. It doesn’t necessarily make us cold, but it chills the general temperature we already have. I have noticed that around a Full Moon, the skies are nearly always clear, especially around the Moon itself, and it is colder and drier. The Full Moon seems to blast through any cloud cover. Even in the current Nighttime fortnight of the Moon Cycle, we have had almost constant rain except for a couple of days around the Full Moon itself.
I have no idea why we get one particular weather pattern rather than another.
The latest Full Moon (6th May 2012) is a Supermoon. This means it is extra close to the planet. Extra Chilly. Extra controlling.
My guess is that the Moon does its recharging when it is in the New Moon fortnight and bathed in constant Sun, particularly at New Moon when it is closest to the Sun. And because it is busy recharging, it is not as controlling.
(see earlier posts: Shooting the Moon, A Giant Planetarium)