Prolonged cold spell on the way

maquiladora

MUSEIST wrote: »

Always remember when reading the charts that from about 96hrs+ the upper temps are always exagerated. So, if its showing -10's for next weekend you can assume that its will be only -5's as it approaches that time. That should be a rule people adhere too to avoid hopeless optimism.

Im sorry but thats absolute nonsense. If you mean "dont get your hopes up in advance", fine. But there is no "law" that says 850 temps are "always exagerated" at some point.

Take the 18Z GFS from 4 days ago at 96 hours showing this evening :



The actual 850s were colder than that this evening, not exaggerated.

Previous runs of the GFS were not developing the shortwave in the same way the ECM did. The GFS then began developing the shortwave and its introduction has led to complications that have led to the colder upper temps not reaching us.

A better rule to have might be "take upper temps at 96+ with a pinch of salt since they can be higher or lower by the time you get to that point".

MUSEIST

maquiladora wrote: »

Im sorry but thats absolute nonsense. If you mean "dont get your hopes up in advance", fine. But there is no "law" that says 850 temps are "always exagerated" at some point.

Take the 18Z GFS from 4 days ago at 96 hours showing this evening :



The actual 850s were colder than that this evening, not exaggerated.

Previous runs of the GFS were not developing the shortwave in the same way the ECM did. The GFS then began developing the shortwave and its introduction has led to complications that have led to the colder upper temps not reaching us.

A better rule to have might be "take upper temps at 96+ with a pinch of salt since they can be higher or lower by the time you get to that point".

I never said that there was a law, I said that there was a very consistant trend in the gfs in particular to over stress the upper temps at medium to long range and hence the constant (not always) back-tracking of these temps over time. I thought it was a fairly obvious observation that some people on here were/are clearly failing to see.

So yeah, everything at 96+ 'with a pinch of salt' sound about right.

madmac187

So is it gonna be as cold? for as long as last year??

Su Campu

maquiladora wrote: »

Im sorry but thats absolute nonsense. If you mean "dont get your hopes up in advance", fine. But there is no "law" that says 850 temps are "always exagerated" at some point.

Take the 18Z GFS from 4 days ago at 96 hours showing this evening :



The actual 850s were colder than that this evening, not exaggerated.

Previous runs of the GFS were not developing the shortwave in the same way the ECM did. The GFS then began developing the shortwave and its introduction has led to complications that have led to the colder upper temps not reaching us.

A better rule to have might be "take upper temps at 96+ with a pinch of salt since they can be higher or lower by the time you get to that point".

It is a fact that the GFS has a bias that brings cold outbreaks too far south beyond +72hrs, and also that the ECMWF is overall a more accurate model.

from Tim Vasquez' "Weather Map Handbook", page 102:

MODEL BIASES
"In meridional flow the GFS can be too agressive with amplifying the pattern and driving cold outbreaks southward, particularly past 72 hours. It is a good idea to consider other guidance such as the ECMWF."

http://www.accuweather.com/blogs/Weathermatrix/story/18097/why-are-the-models-so-inaccurate.asp

"Is the GFS model really worse than the ECMWF?" OK, I went there. Forecasters amateur and professional have long-claimed the U.S. GFS model was more inaccurate than the ECWMF. The graph above proves it, and it is the basis for the business model of the ECWMF's institution, which sells the data at exorbitant prices (the GFS data is free -- a quarter of a million dollars will buy you the rights to use redistribute the ECMWF 25-day forecast, but not their weekly or monthly forecasts which go as far as a year out). Although that makes for a compelling reason to keep their secrets to themselves, they have recently started working with the U.S. government to help determine what's wrong with the GFS.


Last month, a breakthrough was discovered: When the GFS is run with the ECWMF Initialization data (see above), the accuracy improves dramatically (you can read the AMS presentation here). Unfortunately, implementing that is not as easy as you'd think - outside of the cost of using the ECWMF data, it only runs twice a day, so the GFS would no longer be able to run at 06Z & 18Z (midnight & noon). I suppose one other option is that we fix our initialization data, but I haven't heard much about that option taking shape. It would probably be a big undertaking. In any case, I'm thrilled that we now know what's wrong with the GFS.

I've seen this myself over and over, and THAT's why I'm not too confident about the GFS' antics next weekend.....

maquiladora

MUSEIST wrote: »

I never said that there was a law, I said that there was a very consistant trend in the gfs in particular to over stress the upper temps at medium to long range and hence the constant (not always) back-tracking of these temps over time. I thought it was a fairly obvious observation that some people on here were/are clearly failing to see.

So yeah, everything at 96+ 'with a pinch of salt' sound about right.

Thats the point I was trying to make - not always. Your original post however says "upper temps are always exagerated" and you can see by the example above that is simply not true.

Glad we can agree on the pinch of salt.

Rabble Rabble

Is it going to snow in Coleraine, though?

maquiladora

Su Campu wrote: »

It is a fact that the GFS has a bias that brings cold outbreaks too far south beyond +72hrs, and also that the ECMWF is overall a more accurate model.

I'm not disputing that at all Su.

I'm just stating that it's simply false that the upper temps are always exaggerated.

MUSEIST

maquiladora wrote: »

Thats the point I was trying to make - not always. Your original post however says "upper temps are always exagerated" and you can see by the example above that is simply not true.

Glad we can agree on the pinch of salt.

My bad, I did not mean 'always' but 'mostly'. Bring on the snow:cool:

maquiladora

MUSEIST wrote: »

Bring on the snow:cool:

+1

But I'm not feeling very optimistic of snow at low levels from this cold spell myself.

maquiladora

WolfeIRE wrote: »

Very excited about the latest run.

Cold spell will be hanging around for longer than the 7-10 days being indicated up to last night. Snow potential will increase as the week goes on.

I hope you are right Wolfe but my gut feeling now is that a breakdown around the end of the month is likely.

Still though, its only the first cold spell and not even really winter yet. Long way to go.

Redsunset

Just watching Sky News now and there saying 6 inches of snow to hit Britain. Not funny.

Sorry they were only reading out of a paper

maquiladora

redsunset wrote: »

Just watching Sky News now and there saying 6 inches of snow to hit Britain. Not funny.

Sorry they were only reading out of a paper

Let me guess, Daily Mail!

Redsunset

Daily express

SIX INCHES OF SNOW WILL HIT BRITAIN


Britain is facing temperatures as low as -10C this week.


BRITAIN will be hit by a Russian cold blast this week with temperatures as low as -10C (14F) and “significant” snowstorms predicted. But have we got enought salt to cope?


Forecasters last night warned much of the country will be blanketed in snow with up to six inches expected in some areas.

The north and the east are in line for the heaviest snowfalls, although the experts say they could spread across Britain as we head to the weekend. Last night councils said they were ready for the winter’s first serious bout of cold weather which could last a fortnight, with rock salt supplies built up in preparation. Transport bodies say theyhope that there would not be a repeat of last winter’s chaos when grit supplies ran out.

Paul Watters of the AA said although councils had increased their salt stocks, supplies could still run out.





He said: “The Highways Agency has got an extra quarter of a million tonnes in reserve.

“But there’s still a shortfall in the amount of salt available in the UK supply chain.

“We’re up to one million tonnes short and, if we have another harsh winter, stocks could still run out. We can’t afford to be complacent.”

Winter’s first falls hit Teesdale, County Durham, yesterday. But bigger snowstorms are expected to fall in Scotland tomorrow and spread across the whole country by the end of the week.

Met Office spokesman Alex Fox said: “There’s a risk of snow in most parts of the UK and some places will see significant amounts. It’s going to be much colder than average.”



SEARCH UK NEWS for:

We should brace ourselves for sleet and heavy frosts as the country is set to suffer through another harsh winter, the weathermen claimed.

Overnight temperatures are expected to fall to -10C but winds from northern Russia and the Arctic mean it will feel more like -12C in some parts. Mr Fox added: “To put that in context, the last time temperatures reached that low was on the night of March 9 and 10 this year at the top of Braemar, a mountain in Scotland that’s 320 metres above sea level.

“That gives us an idea of how cold things are going to get.”

He said temperatures will drop sharply from 8C today with daytime highs falling as low as -1C by the end of the week – far colder than average November temperatures of two or three degrees.

The Met Office also warned that icy roads and pavements would be dangerous for drivers and pedestrians. Brian Gaze, of The Weather Outlook, predicted up to six inches of snow, especially on higher ground.

He said: ‘The snow is expected to persist until next week with ongoing snow or sleet risk and sharp or severe overnight frost.”

He added: “London may have snow by the weekend, with accumulations of a few inches possible across higher parts of the South-east.”

Bookmaker William Hill is predicting the busiest white Christmas betting year on record, with Aberdeen the 3/1 favourite for snow on Christmas Day and London given odds of 6/1. Jonathan Powell of Positive Weather Solutions warned that Britain is in for a repeat of last year’s winter when the country experienced the coldest few months for 31 years.

He said: “December is looking very cold indeed and it will be similar to last year in temperatures.

“We won’t be seeing as much snow as we did then but with the frost and ice it’s going to be a nightmare.

“There are going to be some pretty sharp frosts and black ice, which makes the roads treacherous for drivers.”

seensensee

sorry for off-topic but does anybody know which site provides live temperature readings through out the counties of ireland?

El Horseboxo

Rabble Rabble wrote: »

Is it going to snow in Coleraine, though?

Been snowing up there since August. Only at night though when the temp drops drastically since it regularly reaches 30+ degrees during the day.

Duiske

seensensee wrote: »

sorry for off-topic but does anybody know which site provides live temperature readings through out the counties of ireland?

Is this any use to you ?

http://www.nratraffic.ie/weather/default.asp?RegionId=0

Cantona's Collars

Some snow in N.E England yesterday.



The English press predicting temps to drop to -10 (it's the Daily Mail so expect sensationalist reporting:D)

jambofc

looking at the charts this cold wet morning in trim this event is getting real now imo,east coast and some northern and north/west areas will be seeing some snow snowers by the end of the week for suuuuuuaaaaaa

darkman2

Things seem to be swinging in the right direction again. This mornings ECM a big boost if you want cold and by next weekend snow.:)

Su Campu

Klara Finkele on Radio 1 just now has given no mention of snow for this week, just rain and hail showers along the east, north and northwest coasts. Daytime temps 3-8°C, severe nighttime frosts, but cloudier Wednesday. She said temperatures remaining several degrees below normal.

She didn't go as far as the weekend, so they're clearly not convinced either.

Looks like a euro "hail"out for the country this week.....

DOCARCH

Su Campu wrote: »

Klara Finkele on Radio 1 just now has given no mention of snow for this week, just rain and hail showers along the east, north and northwest coasts.

Kicking for touch!

darkman2

Looks like there will be some snow showers on the East coast on Wednesday night but the real fun begins on Friday night when they start packing on to the East coast




Also expect increasingly severe frosts and I suspect ice will become an issue aswell.

roryc1

Su Campu wrote: »

Klara Finkele on Radio 1 just now has given no mention of snow for this week, just rain and hail showers along the east, north and northwest coasts. Daytime temps 3-8°C, severe nighttime frosts, but cloudier Wednesday. She said temperatures remaining several degrees below normal.

She didn't go as far as the weekend, so they're clearly not convinced either.

Looks like a euro "hail"out for the country this week.....[/QUOTE

Don’t worry about met eireann, they will give a forecast for snow when there is a few inches already down

But in regards to the weekend, great runs this morning

Speak Now

Whatever happens from next weekend on remains to be seen but in the mean time im going to enjoy a nice cold frosty dry week which is great weather after the month we've had so far

ScallowayLass

I've got my fingers crossed, I live in the Shetland Isles and we have heavy snow forecast for later in the week! Here's hoping;)
Last year we had a snow fall around each full moon from November to March and it froze for the rest of the time, paradise for anyone who loves the snow (as I do).

mickger844posts

seensensee wrote: »

sorry for off-topic but does anybody know which site provides live temperature readings through out the counties of ireland?

Lots here http://www.irelandsweather.com/

eskimocat

good hard frost here this morning, its plenty cold out there!! -2.2 at the moment. Looks like things that are definitely building for some of that lovely lovely white stuff!!

ch750536

Hard frost last night, guestimate a -5.

Pangea

These tempertures look incredible, only mid november and we are in a very cold spell.
In my experience bar last year I didnt even include Decemeber in our real winter month due to us never getting a good cold spell in December.
I have never seen as much frost already so early in the season , even a week before halloween.
I wonder will we have peope argueing on the forum saying they have had enough of this weather by the end of the week?

nacho libre wrote: »

he predicts a warm and dry august. he hasn't said anything about winter yet. i wouldn't get your hopes up about next winter - last winter was a once in 50 year kind of event

Those 50 years are at risk of going very fast Nacho :pac:

maquiladora

Nice 0Z models this morning.

But until we are 48-72 hours out then I'm not changing my mind. I'm still not optimistic of snow at low levels because there is still more than enough time for reality to look very different to what the models show.