The thick bank of cloud on Tuesday morning took until after midday to thin and clear. A maximum of 14.9C, late in the afternoon as the result of strong sunshine, was the turning point after the past cool days being 1C up on the Monday peak, however, it was still 2.4C below average, but going in the right direction. The overnight low of 1.9C was also higher than the previous night but still a significant 5.2C below my long-term average. Although the breeze continued to come from the northeast it was less strong so felt less cold outside.
The change in warmth can be seen in the soil temperature at a depth of 5cm measured at 08.00 each day with 16.7C, 15.6C, 12.8C, 9.0C, and 8.1C respectively, as the warmth slowly left the ground over the past five days, with today a reading of 10.6C, reversing the trend.
We were greeted by welcome sunshine after dawn on Wednesday although a little muted due to thin high cloud. The air temperature recovered quickly having reached 10.4C by 08.00 making it the warmest start to a day at that time since the 3rd.
The forecast track of the Jet Steam, if a little fragmented at the moment, is still lopping around the north of the UK that sees the high-pressure over and around the UK for probably another week with little or no rain likely.
Radiosonde Part 2 – following on from the introduction yesterday.
The first simple radiosonde was invented in France and first flew on January 7th 1929 with much more advanced electronics these days, now being battery powered. The flight of each balloon can last from 90 to 120 minutes and eventually bursts at great height as the barometric pressure has reduced considerably. The maximum altitude attained is determined by the thickness of the balloon and its diameter whilst the temperature at around 25 miles high can have dropped to -90C. Depending on the wind strength the balloon can drift several 100’s kilometres during its flight.
There are six radiosonde stations around the UK, from near Camborne in the southwest to Lerwick and Northern Ireland with around 1,300 worldwide launch sites.
Tomorrow I will include a paragraph on the use of drones to capture meteorological data.