UK Will Act As Atlantic Low Pressure Punch Bag Next 7 Days

Written by Mark Vogan on August 21, 2015 in Rest of Europe, Summer 2015, United Kingdom & Ireland with 0 Comments

We have a strengthening negative NAO pattern developing in which an eastern Canada-Greenland-Scandinavian blocking high joins forces and locks in a deep trough underneath. Because high pressure extends south of Greenland and south of Scandinavia into southern and southwestern Europe, the UK sits beneath the eastern flank of the low in which embedded lows shall rotate around the mother low centred between Scotland and Iceland. Each low will present wind, heavy rain, thunderstorms and surges of heat and humidity from the south frequently over the next 5-7 days.

Prepare for a turbulent week next week with a lot of energy within the atmosphere. The action commences tomorrow as a stalled front lights up as the temperature gradient increases and low pressure forms. Some very heavy rain is expected widely through the central swathe of the UK tomorrow night into Sunday. Expect 30C tomorrow PM around Great London, only 16C in Northwest Scotland.

Credit: AccuWeather Pro

[s2If current_user_can(access_s2member_level1)]

Here’s the NAO index, note how it’s tanking! This has been steady throughout the summer.

nao_fcst

500mb height anomaly over the next 5 days looks like this. The deep trough is locked in by stronger heights on all sides.

Credit: AccuWeather Pro

Because these lows are forming on the base of the trough where air masses of large contrast (between cool, dry and warm, humid) they’ve a lot of moisture to work with and once they track NE over the UK, they’re deflected back out over the Atlantic as they’ve nowhere to go, surrounded by strong and blocking high pressure, the same lows are likely to rotate full circle around the trough and head back into the UK a couple of days later.

ECMWF surface shows the formation of lows at the base of the large upper vortex in which air piles up and pressure lowers.