After a few days respite, particularly across central and eastern areas, the rest of the week and the coming weekend will be dominated by further Atlantic storms crossing the UK. In fact, we are going to see three low pressure centres cross the UK between now and Sunday, spawned along a very active Atlantic jet stream which separates very cold air spilling out of NE Canada and warm moist sub-tropical air rising up from direction of the Bahamas.
The first of these lows is currently deepening to the SW of Ireland, centred around 48 N' 20 W' as of 0900hrs, and is expected to be steered northeast by the strong upper flow across southern Ireland Wednesday morning and northern England tomorrow afternoon/evening. The low will see its deepest phase tonight to the SW of Ireland, falling to around 942mb, before it fills as it crosses the British Isles. This deep low is expected to develop very large wave heights in the SW approaches, with Cornwall, S/W Wales and S Ireland probably seeing the largest waves in the world tomorrow looking at significant wave height forecasts, so coastal flooding may again be an issue at high tide. Winds are likely gale or severe gale force, initially with passage of the frontal system moving through tonight and Wednesday morning ahead of the low pressure system and then on the southern and southeastern flank of the low moving NE across the UK, the strongest winds are likely to be across Wales, southwest and southern England - where we are likely to see gusts of 60mph inland, perhaps 70mph along coasts and maybe a few 80mph gusts across the far southwest. A band of persistent rain moving through overnight/Weds morning and bands of showers following will likely bring up to 20-30mm in places, perhaps up to 40mm over higher ground - so exacerbating already high river levels.
The second low arriving from the southwest early on Friday looks to be slightly shallower feature compared to tomorrow's low by the time the centre crosses southern England, with the strongest winds on its southern flank reserved for northern France. However, as it develops further south over the Atlantic compared to tomorrow's low, it will likely have greater warmth/moisture content wrapped up in its circulation, so heavy rain will be more of an issue than the winds late Thursday and through Friday as this system and its wrap-around fronts move northeast across England and Wales. There is still some uncertainty over the exact track of this low, but it could bring another 20-30mm of rain across southern Britain before the low and its fronts clears later on Friday - so more bad news for the flooding situation.
The Third low arriving this Saturday follows a very similar track to tomorrow's low, the frontal system arriving ahead of the low sweeps rain and gales northeast Friday night, then the strongest winds arrive beneath the core of the low as it passes NE across northern Britain during Saturday, southern Britain bearing the brunt of the strongest winds, with gusts of 70-80mph indicated around southern and western coasts of England and Wales. The rain followed by frequent showers over the weekend bring even more high rainfall totals.
Further lows looks to follow across the UK early next week looking at model output, so a concerning situation for the ongoing flooding issues.
