Big Freeze in early/mid February?

Snowaddict

Subtle changes once again on the latest UKMO 12Z Operational evolution, but it is also relatively similar to that of GFS 12Z Operational.

The first signs of colder air being advected Westwards across the UK & Ireland are now in reach at T+72, with 850mb temperatures of -6, even -7 into Eastern areas later this coming Monday, as pressure begins to fall slightly and a fresh Easterly flow becomes established - introducing a wind chill factor:

12Z UKMO T+72



Throughout the week, towards Thursday, very cold conditions persist with Easterly & Northeasterly winds, generally light to moderate in strength, falling slacker also on some occasions. There are quite solid indications of persistent Heights to the variable North out to T+144. These Heights could also begin to link up with a strong core of High Pressure centred over Eastern Europe and Russia later in the week. Towards T+120 & T+144, as HP begins to retrograde and back Northwest to an extent, there is the threat of an even more unstable and possibly somewhat more cyclonic Easterly pattern approaching.

Conditions generally very cold throughout, with severe frosts quite possible at night time. There is the threat of light sleet & eventually all snow showers in Eastern areas between T+72 and T+144.

Medium Term Indications

There are also increasing indications in the medium term that we will see even more enhanced propagation of the latest warming event at the 30mb level to the Troposphere, as pointed out very well also by Redsunset. This is beginning to come into evidence now at the T+144 timeframe & could well enhance Height Rises to the variable North.

The latest 6-10 Day NOAA 500mb Height Anomoly chart indicates the aforementioned pattern quite well:

http://www.cpc.noaa.gov/products/predictions/610day/610day.03.gif

Both the North Atlantic Oscillation & Arctic Oscillation are also forecast to trend continuously negative for 7 days at least.



Summary

In summary then, present indications suggest that a much colder pattern will indeed become established from next Monday as relatively, but not excessively deep cold air begins to back Westwards across the UK & Ireland. There is the risk of light snow showers in Eastern areas during the midweek period in particular, however there is no current signal for widespread or heavy snow showers, with pressure generally remaining between 1010mb and 1020mb across the country.

Later in the week, a somewhat more cyclonic Easterly/Northeasterly airflow may become established across the country, with even deeper cold arriving.

Overall confidence on the arrival of a much colder pattern is now at about 85%.

SA

patneve2

owen, weather isn't a competition.

irishdub14

jesus, have a flight to catch next thursday, this is the first time im wishing snow doesnt fall!!

owenc

patneve2 wrote: »

owen, weather isn't a competition.

that isnt what i said or ment i was just telling them that it isnt a surprise to see a salter considering they were here since december... and then they got jealous..

LEIN

owenc wrote: »

that isnt what i said or ment i was just telling them that it isnt a surprise to see a salter considering they were here since december... and then they got jealous..

What on earth are you talking about?

Snowaddict

irishdub14 wrote: »

jesus, have a flight to catch next thursday, this is the first time im wishing snow doesnt fall!!

You may just be in luck then

The latest ECMWF 12Z Operational Guidance, while still suggesting a very cold spell developing, with winds eminating predominately from the East, downlpays the risk of any organised snowfall or indeed any organised snow showers.

In general, the potency of the cold, to T+168 on the 12Z Guidance is not quite as potent as the January 2010 Cold Spell. However, towards T+144 the flow does turn more due Easterly & is more continental sourced, with 850mb temperatures of -8 being advected into Ireland.

In general, present guidance suggests only the risk of light snow showers out to Thursday/Friday of next week, albeit with a prolonged spell of blocking and winds generally eminating from the East, perhaps becoming more continental sourced towards Midweek & thereafter, which, despite relatively high pressure readings, could lead to the potential for light snow showers in Eastern areas.

SA

Snowaddict

In addition to the above, it is worth noting that ECMWF 12Z Operational is remarkably consistent tonight & does indeed model a prolonged cold spell..

Now, anything beyond T+120 in general at the moment should be treated with suspicion, but I think it's worth noting that tonight's ECMWF Medium Term Guidance to Day 7 & Beyond is very consistent with it's Stratospheric forecasts.

Extreme blocking is indicated towards T+192 with a vast continental Easterly flow, one which Deep Easterly would certainly be happy with :cool:

ECMWF 12Z Op - 05/02/2010



Such an evolution would also offer the risk of ongoing light snow showers in Eastern areas.

SA

Deep Easterly

Snowaddict wrote: »

Extreme blocking is indicated towards T+192 with a vast continental Easterly flow, one which Deep Easterly would certainly be happy with :cool:

ECMWF 12Z Op - 05/02/2010



Such an evolution would also offer the risk of ongoing light snow showers in Eastern areas.

SA

Classic looking chart SA . Gives me a shiver down the aul back. Let's hope it actually verifies. Some beautiful skyscapes to be had if that plays off!

lucernarian

I'm very suprised that the Atlantic could be stifled so much and this is in Februrary where it would be returning to life if anything.

I am hoping for not so much a prolonged deep cold with showers peppering Ireland, as we saw what that leads to back in December and January. I'd rather have a couple of days of disruptive snow than a prolonged period of burst pipes, massive heating bills and A&Es full of injured people.

Donegal and Wicklow had decent accumulations over the past spell, but apart from heavy wet snow on higher populated ground in Ireland, it's been quite snow-free.

Is there anything in the NWP models to suggest organised precipitation like troughs or else the Atlantic doing battle with the cold air? My look on the charts suggests nothing whatsoever. And Polar Lows?! Pah.

If anyone has the time to find the historic charts,in january '85 [it may have been february but I think it was january and it was definitely '85] in an Easterly, a shallow low developed off wexford and meandered northwards hugging the East coast from Dublin south to Rosslare.
It gave several inches in Dublin,it' snowed from about 11 in the morning right through to about 7 in the evening.
Dublin bus stopped at about 4.

Deep Easterly

Deleted User wrote: »

If anyone has the time to find the historic charts,in january '85 [it may have been february but I think it was january and it was definitely '85] in an Easterly, a shallow low developed off wexford and meandered northwards hugging the East coast from Dublin south to Rosslare.
It gave several inches in Dublin,it' snowed from about 11 in the morning right through to about 7 in the evening.
Dublin bus stopped at about 4.

It will be easy enough to rustle up something. Any idea at all of date?

darkman2

Certainly going to turn much colder now from Monday. The details like 850hpa temps and precipitation will have to wait a couple of more days. Also some relatively minor differences still between the models. The temperature profile looks like it will be broadly similar to January's event. Also the ECM charts tonight are very cold at the surface aswell. Ice and frost becoming widespread again and those snow showers getting going on the East coast. Contrary to opinion above, which I rspect, the ECM after 168hrs shows a cyclonic flow as opposed to anticyclonic so I think showers would be a bit beefier then suggested above. But thats a while out yet.

forkassed

This may interest some snow freaks

Snow storm bears down on US capital


Light flakes started falling around noon (1700 GMT) in downtown D.C. as forecasters warned 30 inches (75 centimeters) or more of heavy, wet snow, accompanied by powerful winds, could fall through Saturday in Washington, Baltimore and surroundings. It could be the heaviest snowfall since January 1922 in the U.S. capital.


Webcam

Deep Easterly

Deep Easterly wrote: »

It will be easy enough to rustle up something. Any idea at all of date?

I've no idea of the date except I think it was january-it was definitely 85 and the easterly[maybe northeasterly] went on for at least a week with light snow showers that stuck prior to the day long event.

nacho libre

damn. i was hoping for active troughs moving from west to east. if only just to see the terror on Jerry Murphy's face:p still, if the ecm can be trusted paddy1 and anyone who enjoys high heating bills should be happy:pac:

also, as was noted earlier the longer it lasts the greater potential for something unexpected to crop up for those in the east and south east. i've resigned myself to the fact i won't be seeing significant fall of snow this winter. so i'm just looking forward to the cold and crisp air and hopefully it'll eventually get cold enough for frost to stay on the trees by day

Redsunset

The only bend in the river i can see is this.







What you think BB

Thats it I'd say.
From personal experience,I can tell you the irish sea delivered in that set up.
Good deep snow including a shallow low in the flow.

nacho libre

Published at 10:00, 1 February BBC

(Next update at 10:00, 8 February)

Written by Jay Wynne

Summary
Briefly milder then very, very cold
As January draws to a close we can confirm that for the whole of the UK, December and January have been the coldest since the winter of 1981/1982. In Scotland it has been the coldest December and January since records began, way back in 1914. It looks like February will do nothing to bring the average temperature up a bit, in fact quite the opposite.


Monday 1 February 2010 to Sunday 7 February 2010

Eventually turning milder
It will take until about Wednesday for the whole of the UK to get back into the milder westerly airstream from the Atlantic. Before then it does turn briefly milder in Scotland with some rain and hill snow, but we're soon back into the colder northerly airstream. Further south it will be a little milder and wetter through Monday night into Tuesday. The second half of the week and into the weekend sees west or southwesterly winds across the UK. With that comes milder conditions, but also bands of rain in association with low pressure systems. During Wednesday, as the transition happens, there could be some significant snow from the Midlands northwards.

Monday 8 February 2010 to Sunday 14 February 2010

Bitter cold returning
High pressure, an anticyclone, will build over Greenland and Scandinavia, and this is going to have a big impact on our weather. Around the edge of that high comes a bitterly cold easterly wind. Temperatures will be well below average for all parts of the UK, with a noticeable windchill factor and severe overnight frosts. Rainfall amounts are likely to be below normal, however snow could well come out of the near continent to affect southern areas at times. Many places will enjoy some cold sunshine but the skies in eastern Scotland and northeast England will probably be rather cloudy.

Monday 15 February 2010 to Sunday 28 February 2010

Staying very cold
There looks to be little change in the big picture. The large anticylone remains in place producing very cold easterly winds and blocking the progress of Atlantic frontal systems from the southwest. It's going to stay very cold with well below average temperatures and severe overnight frosts. Amounts of precipitation are expected to be around normal in the south and east of the UK, but drier than average conditions are expected in the northwest.

Next week
Will the cold march into March?
Monthly forecasting
The weather beyond about a week ahead stretches even the most experienced weather forecaster. Complex numerical weather forecast models from the Met Office and the European Centre for Medium Range Weather Forecasting (ECMWF) are run many times for the month (and season) ahead to build up a picture of the likelihood of different weather types affecting the UK.

they look to be right about the cold coming back(i hope i haven't jinked it by saying that)
it would be fantastic if it does last long as they suggest. although their forecast is for the uk so it's quite possible the atlantic could get back in here. of course in the ideal set-up it would be given a bloody nose and sent packing each time it squared up to the colder air over us.

Deep Easterly

The 17th of Jan 85 looks chilly also:

850's:



500's:



Looking at the stats, a very cold month. Severe frost recorded every night for the first 20 days of the month at both Claremorris and Galway city stations and again towards the end of the month. It was actually much warmer in the east (relatively speaking). Snow also was not exclusively confined to the east. Sounds like a classic month. Will try and post up some countrywide stats later.

It would have been that week alright DE.
Feb '86 iirc was similar and then glorious jan 87.
Those were the spoiled 80's where you had a week of snow nearly every year at some point.

Deep Easterly

Deleted User wrote: »

It would have been that week alright DE.
Feb '86 iirc was similar and then glorious jan 87.
Those were the spoiled 80's where you had a week of snow nearly every year at some point.

Feb 86'. The supreme of all weather events and probably the most easterly month we had in the 20th century. Will never happen again on the scale, at least in our lifetime I would reckon.

nacho libre

Deep Easterly wrote: »

Feb 86'. The supreme of all weather events and probably the most easterly month we had in the 20th century. Will never happen again on the scale, at least in our lifetime I would reckon.

so what were the 850mb temps like back then and how much lieing snow was there?

Deep Easterly

nacho libre wrote: »

so what were the 850mb temps like back then and how much lieing snow was there?

Not much snow, and what little there was tended to be along the east coast; Overall, it was one of the of the driest months on record.

Back to January 1985, here are some of the monthly means from Met Eireann stations for that month:



Looks colder overall than January 2010, esp at inland stations.

Speak Now

owenc wrote: »

Here we go jealousy strikes once more

We'll see who's jealous in the summer :P

Deep Easterly

Jerry Seinfeld wrote: »

We'll see who's jealous in the summer :P

Too right! The north of Ireland might be the snow capital of the nation in the winter, but come summer, we further south will have the heat and the thunderstorms. The summer storms in the north, having experienced a few of them, are weaklings compared to what we get in the Republic.

Bring them on!

WolfeIRE

I really hope the local authorities are stocked up with salt/grit because there are going to be some very cold nights ahead of us.

-8C's above us on Tuesday


through to saturday

ECM keeps it going through to Monday week


By the way forkassed, thanks for that excellent washington webcam. http://www.earthtv.com/en/camera-location/washington-capitol-en

WolfeIRE

I know this is off topic but i had to share lads. It's brilliant

Back on topic, what a nice sunny day it was there:pac:

Deep Easterly

WolfeIRE wrote: »

I know this is off topic but i had to share lads. It's brilliant

Back on topic, what a nice sunny day it was there:pac:

Ha ha! brilliant! :pac::pac::pac:

lucernarian

I do love a bit of nostalga, but only if I can see more of the same next week:p

What are key factors in looking for comma low development, especially with the medium term forecast in mind?

Oh and my idea of medium term is 96-120 hours I suppose, there's little point in looking out for specific snowfall events beyond that. This is Ireland after all!

nacho libre

Deep Easterly wrote: »

Ha ha! brilliant! :pac::pac::pac:

Indeed.:D