After what was a record warm and dry September in many parts of the country, October has other plans for us, offering an abrupt introduction to what Autumn’s really about tonight and over the weekend. Calm, dry and warm will make way for cool, wet and windy, as low pressure reasserts its influence on the northeast Atlantic.
This ECMWF chart for 0000GMT tomorrow shows the strength of the temperature gradient along the polar cold front crossing the country, as well as surface pressure and the wind vectors at 100 m.
The temperature field shown is at 850 hPa (~1500 m) and shows a 10 degree difference between the east coast (13 °C) and just off the west coast (3 °C). Further out in the Atlantic this temperature falls further to around -3 °C at about longitude 20 W, but this will not make any progress further east due to mixing of the lower levels heated by the still-warm Atlantic waters.
This front marks the arrival of a much cooler setup than what we’ve become used to in September and looks set to continue well into next week and beyond. The front will intensify over the eastern half of the country later on Friday, leading to a high risk of flooding as it stalls and pivots over the Irish Sea, under support from a deepening upper trough. Keep an eye out for our Facebook updates throughout the day as we monitor the situation.
Later on Sunday and into Monday we will see the next system bringing more strong winds and heavy rainfall. We will see a continuation of the changeable theme throughout next week as potent lows continue to circulate around the parent low located near Iceland.
Some of you were wondering when we’d see rain again. Be careful what you wish for!