Where’s Jack Frost?

It’s usually around this time of year that this area experiences its first air frosts – but a warm, wet October caused by an active Atlantic and a jet stream sitting close to us has meant that classic radiative cooling nights have been in very short supply. There’s been a couple of chilly nights – down to 2.6C on October 30th and November 5th – but to record an air frost the thermometer must read below 0 Celsius (32Fahrenheit).

The first frost last year was recorded on November 6th. Much hoar was seen around the shady banks of Shoulder of Mutton pond in Wanstead Park

Last year, Wanstead recorded its first air frost on November 6th (-1C). Looking back through the records to 1980 the earliest frost was October 17, 1992, and the latest was January 6th, 2004. Interestingly it appears that having frost in October can signal a mild winter to come!. The median for the first frost is November 16th – 18th. Forecasts for this week suggest we could be scraping the windscreens for the first time on Saturday, thanks to high pressure building in from the Atlantic and calming things down.

Indeed, the models today suggest there is a chance of a block forming in the Atlantic which effectively stops depressions from whistling in from the west, unlocking the door for cooler weather from the north or east. It’s a long way off in meteorological terms though.

Here is a list of first air frosts in Wanstead…