Mountain weather
Eryri / Snowdonia
Confidence
High confidence for a drier period overnight and through Monday daylight hours. High confidence of conditions turning unsettled during Monday evening and lasting though till Thursday. Moderate confidence for a period of heavy snow and freezing rain over hills above 200 M during Monday evening and overnight, before milder air transitions precipitation widely to rain.
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This eveningSunrise:Sunset:
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Mon 16 NovSunrise:Sunset:
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Tue 17 NovSunrise:Sunset:
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Further outlook
This evening forecast
Outbreaks of rain clearing SE with clear spells emerging. Risk of a few isolated showers following from the NW which will fall wintry at height and produce intermittent hill fog. Winds strengthening through the evening with isolated gusts of 30 mph. Summits falling below freezing with a severe wind chill.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Severe Chill Effect
Poor Visibility
Blizzards
Heavy Persistent Rain
Heavy Persistent Snow
Gales
Mountain weather forecast
Cold and largely dry conditions during Monday. Turning wet and windy during the evening with a period of snow and freezing rain before a transition to heavy rain.
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Time
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Time |
00:00
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03:00
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06:00
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09:00
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12:00
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15:00
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18:00
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21:00
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|---|---|---|---|---|---|---|---|---|---|
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Weather
(at 800m)
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Weather symbols |  |
 |
 |
 |
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 |
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Chance of
precipitation (at 800m)
|
Chance of precipitation |
30%
|
30%
|
20%
|
10%
|
10%
|
10%
|
30%
|
90%
|
Wind direction and speed
|
Time
|
Time |
00:00
|
03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|---|---|
|
900m
|
900m | NW 31mph knots
NW
31mph |
NW 29mph knots
NW
29mph |
NW 24mph knots
NW
24mph |
NW 16mph knots
NW
16mph |
NE 8mph knots
NE
8mph |
E 14mph knots
E
14mph |
E 33mph knots
E
33mph |
E 44mph knots
E
44mph |
|
600m
|
600m | NW 19mph knots
NW
19mph |
NW 15mph knots
NW
15mph |
NW 12mph knots
NW
12mph |
NW 6mph knots
NW
6mph |
NE 6mph knots
NE
6mph |
SE 8mph knots
SE
8mph |
SE 20mph knots
SE
20mph |
SE 28mph knots
SE
28mph |
|
300m
|
300m | NW 13mph knots
NW
13mph |
NW 9mph knots
NW
9mph |
NW 7mph knots
NW
7mph |
W 2mph knots
W
2mph |
NE 4mph knots
NE
4mph |
SE 6mph knots
SE
6mph |
E 13mph knots
E
13mph |
SE 21mph knots
SE
21mph |
|
Valley
|
Valley | NW 13mph knots
NW
13mph |
NW 10mph knots
NW
10mph |
NW 7mph knots
NW
7mph |
W 3mph knots
W
3mph |
NE 4mph knots
NE
4mph |
SE 6mph knots
SE
6mph |
SE 13mph knots
SE
13mph |
SE 21mph knots
SE
21mph |
Wind gust
|
Time
|
Time |
00:00
|
03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|---|---|
|
900m
|
900m | 37mph | 35mph | 29mph | 19mph | 10mph | 19mph | 43mph | 56mph |
|
600m
|
600m | 25mph | 22mph | 18mph | 9mph | 8mph | 15mph | 33mph | 42mph |
|
300m
|
300m | 24mph | 20mph | 16mph | 7mph | 7mph | 13mph | 28mph | 39mph |
|
Valley
|
Valley | 24mph | 21mph | 16mph | 7mph | 8mph | 12mph | 27mph | 38mph |
|
Time
|
Time |
00:00
|
03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|---|---|
|
900m
|
900m | ||||||||
|
600m
|
600m | ||||||||
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300m
|
300m | ||||||||
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Valley
|
Valley | ||||||||
| Freezing Level | Freezing Level |
700m
|
500m
|
500m
|
400m
|
400m
|
400m
|
400m
|
400m
|
Additional weather information
Meteorologist's view
Good walking conditions during the day however feeling cold at height with summits staying below freezing. A risk of icy patches during Monday and a light flurry before dawn. Into the evening and overnight, conditions deteriorating quickly with low cloud, hill fog, heavy rain and heavy snow above roughly 200 M making visibility difficult, with near white out conditions at height. Accumulations likely, making navigation difficult and arduous. A gradual transition widely to heavy rain will result in a period of freezing rain over high ground with ice formation possible. A risk of strong 40-45 mph gusts will add to the hazardous conditions, combined with a severe wind chill below MINUS 12 C over summits. A risk of being blown off balance.
Weather
Cold with clear spells to start Monday with a frost likely. A chance of a light wintry shower during the early hours from the NW. Increasing medium to high level cloud through Monday and remaining dry until late evening. Precipitation, locally heavy spreading from the SW during the overnight hours falling as snow and then to freezing rain above 200 M. A gradual transition widely to rain is expected by dawn with accumulations at height expected to thaw. Cloud will be low enough through this period to produce hill fog with poor visibility expected widely. Winds switching to a strengthening ESE and gusting to 40-45 mph during evening and overnight.
Chance of cloud-free hill tops
80% through the day then 10% during the evening.
Low cloud and visibility
Isolated patches of cloud early morning then excellent visibility during the day before evening low cloud and precipitation produces poor to very poor visibility.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Weather
Initial icy conditions possible over summits with thawing snow. Overnight rain and extensive hill fog pushing north through the course of the morning, with heavy showers to spells of rain following on through the day. Cloudy conditions widely, low enough for intermittent hill fog with only a few brighter spells later in the day. A severe wind chill over high ground with summits struggling to rise above freezing.
Chance of cloud-free hill tops
10% during the morning with 40% later into the afternoon.
Maximum wind speed expected
Isolated gusts of 30-35 mph possible during the day before gradually easing into the night.
Temperature
- At 800m Plus 01 C.
- Valley Plus 08 C.
- Freezing level 1400 M.
Low cloud and visibility
Extensive low cloud and poor to very poor visibility during the morning. Temporary visibility reduction following through the afternoon and evening associated with showers to spells of rain along with transient hill fog.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Wed 18 Nov
A continuation of unsettled showery conditions on Wednesday with heavy and perhaps locally thundery showers merging to spells of rain. Largely cloudy with cloud low enough at times for hill fog. Freezing level around 1400 M.
Thu 19 Nov
Showery conditions with a period of hill fog expected to gradually clear south through Thursday with clearer and drier conditions emerging during the evening. A frost forming with a notable wind chill overnight. Freezing level falling from 1400 M to 600 M overnight.
Fri 20 Nov
A drier and colder day with largely fine conditions however summits struggling to rise above freezing with a severe wind chill. Freezing level around 600 M.
Summit specific forecast
Mountain summits
Other points of interest
Cluster of multiple stations