Includes all summits in the the northern half of Wales from Pumlumon northwards.
Eryri / Snowdonia National Park
Wednesday 6th December 2023
Last updated
Tue 5th Dec 23 at
4:28PM
After a hard frost, mostly dry and bright, but feeling increasingly bitterly cold as southeasterly winds strengthen and cloud thicken through the day ahead of a front, which will bring and increasing risk of upland snowfall, in across western mountains toward evening, and then spreading to all parts overnight.
Early sun, then overcast. Bitter chill as winds strengthen. Upland snow later.
Southeasterly, strengthening through day from around 30mph after dawn to 40 to locally 50mph before dusk.
Walking increasingly difficult, in places on lower slopes, and feeling bitterly cold as wind chill becomes significant.
Dry much of day, then periods of snow from late afternoon; whiteout
Dry for much of daylight, but fronts edging in from southwest will bring rain and persistent upland snow from mid to late afternoon, giving whiteout. Reverting to rain to all levels overnight.
Hills may be cloud free; before lowering to blanket the hills
Summits likely to start cloud free in the morning. Will deteriorate, during afternoon when snow arrives as cloud lowers to 300m or lower east Wales and 450 to 650m west.
70% lowering later in afternoon to 10%
Early sun, but soon overcast as cloud thickens. Appalling or near zero visibility in the upland snow that arrives late in the afternoon.
-1 or 0C (only a degree or so warmer in valleys). Will feel as cold as minus 16C directly in the wind.
Almost all terrain at least partly frozen.
Eryri / Snowdonia National Park
Thursday 7th December 2023
Last updated
Tue 5th Dec 23 at
4:28PM
Very turbulent conditions developing. Southeasterly, later southerly, winds; lifting through day to 50 to 70mph.
Be prepared for increasingly very difficult conditions, as turbulent and very powerful winds accelerate over the mountains.
Frequent rain, heavy at times.
Frequent spells of rain and drizzle through the day. May become heavy or intense later in the day as an active front moves in, perhaps with local thunder.
Extensive
Extensive hill fog from mid slopes upwards, perhaps lower slopes near west coast and more especially mid Wales.
20%
Overcast. Poor or very poor visibilities.
3C, Feeling closer to -15C in exposure to the wind.
Above the summits, but ground from mid slopes up, still partially frozen, with slow-continued thaw.
Eryri / Snowdonia National Park
Friday 8th December 2023
Last updated
Tue 5th Dec 23 at
4:28PM
Southerly 40 to 60mph at first, but as low tracks in, winds will veer southwesterly and ease 25 to 40mph, maybe less.
Be prepared for difficult conditions with significant wind chill and buffeting. Slowly moderate into the afternoon.
Frequent, at times heavy, rainfall.
Low pressure will drive frequent, and at times heavy, rainfall into the area through the day. Setting in at times in the west.
Extensive
Extensive hill fog will cover the hills throughout the day. Mostly mid to upper slopes initially, but patches descending to lowers slopes in rain as winds veer.
20%
Little if any sun. Visibility often poor due to rain.
Around 3C, but feeling more like -10C or below in direct exposure to the strongest winds.
Above the summits, with upper level terrain continuing to thaw out.
Unsettled conditions will prevail over the next week to 10 days, with periods of upland gales or severe gales with precipitation frequent, mostly rain, although intermittently snow Scottish Highlands, more rarely elsewhere. Driest conditions (relative to the average) will likely be in the northwest Highlands, given the often backed flow, as the low pressure areas track in.