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Isolated Frost

Isolated Frost Presents: Great Britain December 2010 Forecast

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December:

N Scotland + Shetland/Orkney/Western Isles (80% Temp./70% Precip.)

I expect a cooler than average start to temperatures with blocking towards Greenland, the blocking slowly moves southwards and gives a westerly-dominated start to the month, NW & W continue throughout, with temperatures around average, snowfall throughout the Western Isles and the Nevis/Cairngorm area will be slightly cooler, with NE Scotland and the Northern Isles, the 528 Dam Line slowly moves south throughout and the Northerly Blocking moves Eastwards, giving Wintry PPN to most of this area, uppers of around -8/-10 throughout the cold spell with NNE & NE's dominating. As the month goes on, the winds pull from the East, and a small Scandi High arrives. Cold end with snow-covered New Year period for most.

Rest of Scotland (70% Temp./90% Precip.)

I expect a cool, wet start with Wintry PPN throughout the Central areas and Scottish Border region. I expect the wet weather to continue, until a settled patch in the middle of the month, giving below average temperatures and clear skies, with hard frosts above 300/500m. Then, as the wind moves Easterly during the latter part of the month, snow showers hit, giving cool temperatures and heavy falls, I expect the Air Pressure to be above average throughout the month. Coldest along the Western areas.

N England (80% Temp./60% Precip)

I expect a cool start in the west, with warmer temperatures in the East. I forsee hard frosts in the Pennines and Lake District area, with heavy snowfall in the North West. I predict a turn in fortunes, with the East seeing the cooler weather in the mid and latter parts of the month, with below average Precip. and dryness throughout, I think there will be NE dominated month, with snow showers along the NE Coast and North York Moors at times, but overall dryness prevails, with some Westerly winds giving snowfall to areas in the North Pennines and Yorkshire. I think that throughout Yorkshire, it will be coolest, thanks to prevailing Northerlies and North Easterlies, and a White Christmas and New Year to Yorkshire and Humberside.

Midlands (70% Temp./50% Precip.)

I think the Midlands will be repaid, after falling behind last year, I think it will see a similar picture to Yorkshire, with cold throughout, the West Midlands will be coldest, with frost hollows experiencing -10C throughout the month, and snowfall to be widespread during N'ly/E'ly spells, especially along the East Coast. I think that thanks to blocking in the NE, cold shoots of air will give record low windchill temps. throughout the month. I expect some stormy conditions towards the end of the month, in the East Midlands, thanks to NE'ly and W'ly colliding, with low pressure.

SW England & Wales (90% Temp./80% Precip.)

I expect a cold, wet and snowy start to the month, along with some mild evenings. As the Northerly/North Easterly' arrives, a cold spell arrives, with dry weather, ensuring most snow collected from the start of the month, is preserved without additional falls. The cold continues, until South Wales and the South West see a milder spell towards the end of the month, with hailstorms, along with Thunderstorms, a W'ly takes control towards January.

S & SE England (70% Temp./90% Precip.)

I expect an average, to warm start, apart from on the South Coast to December. With cold N'ly spells giving some falls to the rural areas of the region. I then expect the middle of the month to be cold and dry, and transitional, as the temps slowly fall and precipitation lands as snowfall in London aswell, giving a perfect scenario after Christmas, as a NE'ly blasts the region, with heavy falls, and low temps.

So, roughly along the same lines as NW, cool and dry, with a late outburst. I think the CET will be 3.2C and the E&W Rainfall Series will come out at 70%.

I think a cold month for pretty much everywhere, I think the prevailing wind will be NW/NNW in the Western areas of England & Wales, with N/NNE/NE on the Eastern Coastline area.

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How does having percentage anomalies for temperature work, then?

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How does having percentage anomalies for temperature work, then?

100% = Average local value

I.E. The av. temp for N England is 5C, the temp for 2010 December is 4C if 80%, 3C if 60%, or 8C is 160%. Same for precip.

All in all, practically basing this year's December average on the long term one.

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Interesting prognosis, and I hope it comes to pass.

What tools/teleconnections/analogues did you use to help with your forecast?

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Interesting prognosis, and I hope it comes to pass.

What tools/teleconnections/analogues did you use to help with your forecast?

I've used what I expect from the CFS models, the teleconnections of La Nina and what I think looks like being it's affect on the Atlantic this year, the summary of patterns on a strong La Nina, aswell as the current European Pressure/Pattern situation. I've been checking precipitation and pressure models for precip. figures and I've been following the situation of the Gulf Stream, along with the current AO & NAO situations.

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100% = Average local value

I.E. The av. temp for N England is 5C, the temp for 2010 December is 4C if 80%, 3C if 60%, or 8C is 160%. Same for precip.

All in all, practically basing this year's December average on the long term one.

I hope you realise that is not a valid methodology.

You can only use proportions if you use an absolute scale - for temperature this is the Kelvin scale.

An example of why using Celsius won't work:

What's 50% of 0.1C?

0.05C? No. Its approx -136C (using the absolute Kelvin scale).

Hopefully you can appreciate that this is not a sensible way to compare temperature anomalies, and is why absolute anomalies are used.

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very well put together 'isolated frost' its exciting studying the data, and then putting out your forecast for others to read/hear is a good feeling, anyway keep it up and hope to see a january forecast.

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I hope you realise that is not a valid methodology.

You can only use proportions if you use an absolute scale - for temperature this is the Kelvin scale.

An example of why using Celsius won't work:

What's 50% of 0.1C?

0.05C? No. Its approx -136C (using the absolute Kelvin scale).

Hopefully you can appreciate that this is not a sensible way to compare temperature anomalies, and is why absolute anomalies are used.

i think everybody knows what he means...give him a break :wallbash:

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Timmead, is there anything you will not criticise?

I eagerly await your own winter forecast!

Nobody likes a smart a#se.

Well done for having a go Isolated!

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I hope you realise that is not a valid methodology.

You can only use proportions if you use an absolute scale - for temperature this is the Kelvin scale.

An example of why using Celsius won't work:

What's 50% of 0.1C?

0.05C? No. Its approx -136C (using the absolute Kelvin scale).

Hopefully you can appreciate that this is not a sensible way to compare temperature anomalies, and is why absolute anomalies are used.

:lol: and this is why i stay out of weather discussion! get real! the guy has had a punt at a forecast, at least give him credit for publishing it and making an effort. :rolleyes::nonono:

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I eagerly await your own winter forecast!

Nobody likes a smart a#se.

Well done for having a go Isolated!

Well put but is a#se technically correct I ponder?

H

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To be honest I think I could produce a more accurate forecast by flipping a coin.

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To be honest I think I could produce a more accurate forecast by flipping a coin.

Is that how the metoffice did their long range forecasts?

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To be honest I think I could produce a more accurate forecast by flipping a coin.

.....Hopefully you can appreciate that this is not a sensible way to compare temperature anomalies......

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December:

N Scotland + Shetland/Orkney/Western Isles (80% Temp./70% Precip.)

I expect a cooler than average start to temperatures with blocking towards Greenland, the blocking slowly moves southwards and gives a westerly-dominated start to the month, NW & W continue throughout, with temperatures around average, snowfall throughout the Western Isles and the Nevis/Cairngorm area will be slightly cooler, with NE Scotland and the Northern Isles, the 528 Dam Line slowly moves south throughout and the Northerly Blocking moves Eastwards, giving Wintry PPN to most of this area, uppers of around -8/-10 throughout the cold spell with NNE & NE's dominating. As the month goes on, the winds pull from the East, and a small Scandi High arrives. Cold end with snow-covered New Year period for most.

Rest of Scotland (70% Temp./90% Precip.)

I expect a cool, wet start with Wintry PPN throughout the Central areas and Scottish Border region. I expect the wet weather to continue, until a settled patch in the middle of the month, giving below average temperatures and clear skies, with hard frosts above 300/500m. Then, as the wind moves Easterly during the latter part of the month, snow showers hit, giving cool temperatures and heavy falls, I expect the Air Pressure to be above average throughout the month. Coldest along the Western areas.

N England (80% Temp./60% Precip)

I expect a cool start in the west, with warmer temperatures in the East. I forsee hard frosts in the Pennines and Lake District area, with heavy snowfall in the North West. I predict a turn in fortunes, with the East seeing the cooler weather in the mid and latter parts of the month, with below average Precip. and dryness throughout, I think there will be NE dominated month, with snow showers along the NE Coast and North York Moors at times, but overall dryness prevails, with some Westerly winds giving snowfall to areas in the North Pennines and Yorkshire. I think that throughout Yorkshire, it will be coolest, thanks to prevailing Northerlies and North Easterlies, and a White Christmas and New Year to Yorkshire and Humberside.

Midlands (70% Temp./50% Precip.)

I think the Midlands will be repaid, after falling behind last year, I think it will see a similar picture to Yorkshire, with cold throughout, the West Midlands will be coldest, with frost hollows experiencing -10C throughout the month, and snowfall to be widespread during N'ly/E'ly spells, especially along the East Coast. I think that thanks to blocking in the NE, cold shoots of air will give record low windchill temps. throughout the month. I expect some stormy conditions towards the end of the month, in the East Midlands, thanks to NE'ly and W'ly colliding, with low pressure.

SW England & Wales (90% Temp./80% Precip.)

I expect a cold, wet and snowy start to the month, along with some mild evenings. As the Northerly/North Easterly' arrives, a cold spell arrives, with dry weather, ensuring most snow collected from the start of the month, is preserved without additional falls. The cold continues, until South Wales and the South West see a milder spell towards the end of the month, with hailstorms, along with Thunderstorms, a W'ly takes control towards January.

S & SE England (70% Temp./90% Precip.)

I expect an average, to warm start, apart from on the South Coast to December. With cold N'ly spells giving some falls to the rural areas of the region. I then expect the middle of the month to be cold and dry, and transitional, as the temps slowly fall and precipitation lands as snowfall in London aswell, giving a perfect scenario after Christmas, as a NE'ly blasts the region, with heavy falls, and low temps.

So, roughly along the same lines as NW, cool and dry, with a late outburst. I think the CET will be 3.2C and the E&W Rainfall Series will come out at 70%.

I think a cold month for pretty much everywhere, I think the prevailing wind will be NW/NNW in the Western areas of England & Wales, with N/NNE/NE on the Eastern Coastline area.

Nice forecast for my area; hope that works out at as hoped. Just one niggle, where is Humberside? Its not on any map I have seen since 1996. Really bugs me... you mean Northern Lincolnshire!

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Good effort Isolated Frost :)

Hopefully the thread won't get locked because of some of the other members.

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I hope you realise that is not a valid methodology.

You can only use proportions if you use an absolute scale - for temperature this is the Kelvin scale.

An example of why using Celsius won't work:

What's 50% of 0.1C?

0.05C? No. Its approx -136C (using the absolute Kelvin scale).

Hopefully you can appreciate that this is not a sensible way to compare temperature anomalies, and is why absolute anomalies are used.

You are right, but I don't think it really matters, we get the general idea of what I.F. means.

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Not bad I.F., although you didn't include Northern Ireland and Ireland...naughty....:acute:

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Not bad I.F., although you didn't include Northern Ireland and Ireland...naughty....:acute:

maybe he would add NI/I in later?

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maybe he would add NI/I in later?

They will be added on my full December-March Forecast on December 4th.

The possible Bartlett High in FI could signal a slightly different start to December, if it's still there by then.

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Looking forward to your Dec-March forecast IF. It is people like you that make this Forum so interesting as Winter approaches. Keep up the good work!

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How does having percentage anomalies for temperature work, then?

Good question though I sussed this out for myself.

I hope you realise that is not a valid methodology.

You can only use proportions if you use an absolute scale - for temperature this is the Kelvin scale.

An example of why using Celsius won't work:

What's 50% of 0.1C?

0.05C? No. Its approx -136C (using the absolute Kelvin scale).

Hopefully you can appreciate that this is not a sensible way to compare temperature anomalies, and is why absolute anomalies are used.

Stop being so pedantic

To be honest I think I could produce a more accurate forecast by flipping a coin.

Im still waiting!:whistling: No plagerising the METO forecast now.

IF thank you for putting together such a nice, no full of technical nonsense weather forecast. It was consise and had a methodology to it that actually made sense. You seperated the UK into regions instead of date zones which to me means Im not having to drag myself around reasing all about SE England. You used the CFS forecast and the Greenie High, which again Im sure will be the single most important meteorlogical factor this coming winter. And Yes Im delighted first class effort!

Look forward to January.

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Good question though I sussed this out for myself.

Stop being so pedantic

Im still waiting!:whistling: No plagerising the METO forecast now.

IF thank you for putting together such a nice, no full of technical nonsense weather forecast. It was consise and had a methodology to it that actually made sense. You seperated the UK into regions instead of date zones which to me means Im not having to drag myself around reasing all about SE England. You used the CFS forecast and the Greenie High, which again Im sure will be the single most important meteorlogical factor this coming winter. And Yes Im delighted first class effort!

Look forward to January.

Thanks for the feedback. The zones are the most important part to me, as the papers usually read: SE England = UK.

Looking forward to your Dec-March forecast IF. It is people like you that make this Forum so interesting as Winter approaches. Keep up the good work!

Blush. Thanks. Will do the Ireland forecast for the winter soon!

Also thanks to everyone commenting, even tinmead, always interesting to learn new stuff...

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