Llwytmor (Gwynedd) weather

Headline:

Persistent heavy rain and windy throughout. Heaviest over hills.

Today:

Heavy rain in the north continues, before heavy outbreaks of rain across the country towards the afternoon. Heaviest in the south later, but continuous throughout. Strong winds, with risk of coastal gales. Flooding risk in northern and central areas. Maximum temperature 11 °C.

Tonight:

The rain continues, with heavy outbursts through the evening affecting many, especially in northernmost and southernmost areas. Widespread heavy rain, potentially torrential over higher ground, by dawn. Continued flooding risk. Minimum temperature 7 °C.

Wednesday:

Widespread heavy rain, torrential over hills, through the morning, heaviest in the north before noon, and heaviest in the south in the afternoon. Continued flooding risk. Easing later, showers overnight. Maximum temperature 11 °C.

Outlook for Thursday to Saturday:

Colder, with lighter winds on Thursday and Friday, with scattered showers and sunny spells. A dry start, before widespread rain through the morning, and showers later.

Updated: 04:00 (UTC) on Tue 19 Jan 2021

Rather cold and unsettled conditions look likely for most of the UK, as a low pressure system remains to the northeast. Northwesterly winds from this system are expected to bring frequent showers, particularly to north and west-facing coasts, and this will likely fall as snow over high level areas, and also down to lower levels at times. Atlantic low-pressure systems are expected to cross the south/central parts of the country at times, bringing rainfall and periods of slightly milder temperatures, and there will be a risk of snowfall on the boundary between the mild and cold air masses. Northern and central areas are more likely to be affected by wintry hazards during this period. Temperatures mostly rather cold, but closer to average near approaching lows in the south.

Updated: 04:00 (UTC) on Tue 19 Jan 2021

Confidence for this period is low, though there is a signal for weaker than average westerly winds and for Atlantic low-pressure systems to track further south than normal. This will bring below-average temperatures to the north of the UK, with a greater than normal risk of wintry precipitation. Further south, there is a continued risk of unsettled conditions, with above-average rainfall and periods of slightly above average temperatures. There remains the potential for significant snowfall along the boundary between colder air to the north, and the milder air in the south, with the greatest risk across central and northern areas. Through this period there is a greater than average chance of cold spells spreading across the whole UK at times with the associated risk of wintry hazards.

Updated: 04:00 (UTC) on Tue 19 Jan 2021