Flex Your Head
Well-known member
"A wee bit of snow in the forecast for the weekend" according to Carol Thingie on BBC Breakfast.
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[Misc] The Award-winning official "More Snow Tomorrow?" Thread [2024-25 Season]
- Thread starter Giraffe
- Start date
Papa Lazarou
Living in a De Zerbi wonderland
As many said yesterday there is still a huge amount of uncertainty over what type of weather we will get next week.
Until then, all models broadly agree. The change starts Saturday, when a Low pressure is forecast to move SE over the Western side of Britain and on down into France by Sunday. Rain will move across West and SW Britain with some sleet or snow over the hills possible before an Easterly wind sets in for Sunday with some wintry showers of sleet or snow in the East. It will become cold everywhere by then.
There are minor differences in the models, chiefly relating to just how quickly the colder air to the east will move over the UK. The GFS has been for some time showing this happening quickly, and has been showing rain turning to snow on Saturday night for some time. However, guidance from Met Office forecasters suggest that they tend to disregard the GFS prec type forecasts, as they tend to over-represent snow.
Either way, IF conditions were perfect (low enough 850hpa temps, a cold low level feed from the East, heavy enough precipitation, etc etc) I wouldn't be surprised to see reports of snow overnight Sat - Sun.
Sunday looks a cold day with showers, wintry in the East. It depends on where the low sits over France as to whether we get some action... it will feel much colder though.
The forecasting challenge (at least from a model perspective) comes Mon - Tuesday (120 hours time roughly)
What previous GFS runs have shown is what the current ECM output is showing. The chart below shows this.
Following the cold snap, a low which formed arond Icleland slip SE towards the UK. This is key as it follows a similar path to the previous one and re-inforces the low over France. This then support the High to the North of us, allowing much colder air to the East to be dragged over us, extending the cold spell.
The UKMO shows this to an extent, and does show a longer cold spell
However, the GFS Op run builds a ridge over the UK, which allows the low to miss the UK and progress towards Scandinavia. This kills the block, and the High sinks SE into europe, allowing the Atlantic to reach us a few days later.
The ECM is a very snowy run all the way through, and ends with this.. an intensely cold blast from the NE
Laridae
Active member
Re: The award-winning official "More snow tomorrow?" thread [2012-13 season]
That last image looks NASTY! Bring on the snow!!
That last image looks NASTY! Bring on the snow!!
Green Cross Code Man
Wunt be druv
Re: The award-winning official "More snow tomorrow?" thread [2012-13 season]
but it's FI anyway as its sooo far off.
That last image looks NASTY! Bring on the snow!!
but it's FI anyway as its sooo far off.
Papa Lazarou
Living in a De Zerbi wonderland
Looking purely at the GFS ensemble FI seems to start at Sunday night.
The rubbish blue arrow shows the last point where there is decent agreement, after which there is wide divergence in terms of 850hpa and (not shown) surface temps.
I've also added a red circle to highlight the good snow chances over the weekend.
chucky1973
New member
this all goes over my head!!! But may just get my hat and gloves out for Sunday just in case!!
Papa Lazarou
Living in a De Zerbi wonderland
Yes, Sunday will be cold.
The latest GFS is a horror show for cold weather. The 'turning point' I mentioned up-thread has turned very much for the worst. The low zips of East, the high collapses, and the Atlantic rushes back in...
The failed cold spell in mid Dec felt very much like this --> GFS goes for cold, sticks to its guns - UKMO comes onboard, ECM comes onbaord for 6 hours --> GFS backtracks immediately, all other models follow.
I'm very very keen to see the GFS ensembles for this, as that will tell just how bad this is for cold and snow next week.
Hillian1
( . ) ( . )
Yes, Sunday will be cold.
The latest GFS is a horror show for cold weather. The 'turning point' I mentioned up-thread has turned very much for the worst. The low zips of East, the high collapses, and the Atlantic rushes back in...
The failed cold spell in mid Dec felt very much like this --> GFS goes for cold, sticks to its guns - UKMO comes onboard, ECM comes onbaord for 6 hours --> GFS backtracks immediately, all other models follow.
I'm very very keen to see the GFS ensembles for this, as that will tell just how bad this is for cold and snow next week.
Papa, when you say bad, do you mean bad for you snow lovers or bad for us snow haters?
chucky1973
New member
im glad you asked and not me, i feel stupid asking those sort of questions, "as in have you not been listening kid"
swindonseagull
Well-known member
please lets have some proper winter weather
Papa Lazarou
Living in a De Zerbi wonderland
to answer you both - potentially bad for snow lovers.
Hillian1
( . ) ( . )
Flex Your Head
Well-known member
When will you be able take a look at the GFS, Papa?I'm very very keen to see the GFS ensembles for this, as that will tell just how bad this is for cold and snow next week.
I've had a bad feeling about this winter ever since we got let down so badly with the 'Beast From the East" which turned out to be a dead chaffinch.
chucky1973
New member
boooooooo
Papa Lazarou
Living in a De Zerbi wonderland
The short version (Hi Resolution part) is out now.
Meteociel - Diagrammes GEFS
The Op & Control (the 2 highest res runs) are close to mild outliers, which is reassuring, BUT sometimes when these 2 agree on a different evolution it can be the emergence of a new solution.
GFS is currently on it's own, so taking into account the other models I'd say we're still 70/30 in favour of a cold spell from the weekend. The 12Z runs later on will be key. If the other big guns (UKMO & ECM) stick to the cold outlook we're looking good, and of course the GFS may come back to cold.
The very latest UKMO forecast is encouraging:
SK1NT
Well-known member
Papa Lazarou
Living in a De Zerbi wonderland
It's still a possibility...
Papa Lazarou
Living in a De Zerbi wonderland
Hillian1
( . ) ( . )
Don't ask such bloody foolish questions, all I see is lots of coloured lines.
What do YOU think?
