Cold Spell Chart, Forecast Analysis & Warnings- 29/11/2010 onwards

ninebeanrows · 29-11-2010 3:01pm #1

Please use this thread strictly for discussion of weather charts and forecasts.

Use the other thread for general chat.

mickger844posts · 29-11-2010 3:06pm

For people wondering when the snow will hit click on Nedbor on this site to give an indication of what hopefully will happen. http://www.dmi.dk/dmi/index/danmark/vejrkort.htm

cherryghost · 29-11-2010 3:25pm

Posted on the other thread. System tonight looks strong enough to continue on til Tuesday afternoon, spreading across the country

attachment.php?attachmentid=137167&stc=1&d=1291036817

attachment.php?attachmentid=137167&stc=1&d=1291036817

lucernarian · 29-11-2010 3:28pm

Why the hell does the NAE 06z chart have to be witheld or whatever from weatheronline?! This would help matters significantly if I had access to it.

29-11-2010 3:30pm

Rougies wrote: »

I think Evelyn must have held the meteireann website editor at gunpoint to type that forecast and warning today.
I can picture it clearly ... "But Evelyn, 20cm .. that's nearly 8 inches!! We can't do that!" ... "Ok smartass, lets make that 25cm ... how do you like 10inches! Type it now or get a bullet in the head!"

edit: Sound like she's made it to the TV studio now too, poor Nuala must have been petrified :O

Lol quoted for truth!
For what it's worth,it is getting very marginal on the coast,that may or may not be the case after dark.
I'm sceptical of any of the forecasted dumpings to reach south wicklow or north wexford.
We shall see.
They could well come into Dublin,louth and the rest of wicklow alright with some coasts see'ing a sleety mix including central Dublin.

That said,theres no thaw worth talking about here despite the air temp being 2.1c
dp is -0.1c
We had the lightest of the lightest snow here an hour ago.

lucernarian · 29-11-2010 3:30pm

Cherryghost, could you indicate what Weather forecasting model that chart comes from?

Edit: I note with interest that the temperature at Ronaldsway airport in the IoM has dropped to 2 degrees at 2.20 from 3 degrees at 1.50, which is a very positive sign. HOWEVER a met office station to the north of Blackpool, which is not even halfway across the Irish Sea, had temperatures rising to 3 degrees at 1pm. I'm awaiting the 2pm readings with interest.

cherryghost · 29-11-2010 3:36pm

http://www.wunderground.com/modelmaps/maps.asp?model=GFS&domain=EU

Here ya go

ninebeanrows · 29-11-2010 3:42pm

To_be_confirmed wrote: »

Why the hell does the NAE 06z chart have to be witheld or whatever from weatheronline?! This would help matters significantly if I had access to it.

Really really annoying.

Always seems to be the case during severe weather etc.

Sponge Bob · 29-11-2010 4:02pm

Jet Stream forming block offshore

H2UMrsRobinson · 29-11-2010 4:08pm

^
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| is that good or bad
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Dotsie~tmp · 29-11-2010 4:11pm

48H accumulation. Looks good to me.

cherryghost · 29-11-2010 4:11pm

In terms of this weekends weather yes, the entire country would be in for a dumping

danni2 · 29-11-2010 4:36pm

Ok it looks like some heavy snow is forecast for the east in the next 24-48 hours, how far inland will the snow travel, will they make it as far as the midlands?

nacho libre · 29-11-2010 4:43pm

danni2 wrote: »

Ok it looks like some heavy snow is forecast for the east in the next 24-48 hours, how far inland will the snow travel, will they make it as far as the midlands?

http://www.yr.no/place/Ireland/Offaly/Clara/advanced_map.html

cherryghost · 29-11-2010 4:45pm

danni2 wrote: »

Ok it looks like some heavy snow is forecast for the east in the next 24-48 hours, how far inland will the snow travel, will they make it as far as the midlands?

Looks as though it might go as far as eastern Galway from somecharts, stretching downwards to Tipp and pulling back to Waterford, while a seperate batch is concentrated on Cork/Kerry

nacho libre · 29-11-2010 4:48pm

cherryghost wrote: »

Looks as though it might go as far as eastern Galway from somecharts,

yes. it would seem so.
http://www.yr.no/place/Ireland/Galway/Clifden/advanced_map.html

it will be interesting to see how much energy is left in it by the time it gets to the midlands.

danni2 · 29-11-2010 4:53pm

Thanks guys, and thanks for that link nacho;)

maquiladora · 29-11-2010 5:03pm

The very latest 12Z NAE showing heavy snow in Dublin/Louth area early Tuesday morning.

Dotsie~tmp · 29-11-2010 5:15pm

Upgrade to 48H percip. accum.

ninebeanrows · 29-11-2010 5:16pm

maquiladora wrote: »

The very latest 12Z NAE showing heavy snow in Dublin/Louth area early Tuesday morning.

Ya beat me!

That chart looks smashing for here.

GFS still progging exceptional, and potential for record breaking temperatures during Thursday night.

darkman2 · 29-11-2010 5:26pm

Weathercheck wrote: »

That chart looks smashing for here.

Dew Points

Could be alot of snow during tomorrow though. Won't be snow at 6am on that evidence however (on coasts).

From 9am is very interesting.

But the 12z GFS beings in the much colder air slower and delays the transition back to snow till tomorrow afternoon...

Iancar29 · 29-11-2010 5:35pm

SKy news weather forecast was just amazing for leinster!:D

10-10-20 · 29-11-2010 5:40pm

I wonder will this work...
It should show the latest MET radar and also Sat24's output.

From: http://met.ie/latest/rainfall_radar.asp?ani=y

image.ashx?ok=1&country=eu&type=slide&index=1&sat

From: http://www.sat24.com/

homolumo · 29-11-2010 5:43pm

maquiladora wrote: »

The very latest 12Z NAE showing heavy snow in Dublin/Louth area early Tuesday morning.

Do you think we will see any of that?

Trogdor · 29-11-2010 6:01pm

Anyway know what surface winds are to be like on East coasts tonight? (Or have a hi-res chart from any recent model output?)Winds have gone North-West again in Bray which i think will spell snow for sure here if that direction can hold overnight. Today during the day was the first Easterly interlude in the surface winds here in the last few days!

pistolpetes11 · 29-11-2010 6:14pm

trogdor wrote: »

Anyway know what surface winds are to be like on East coasts tonight? (Or have a hi-res chart from any recent model output?)Winds have gone North-West again in Bray which i think will spell snow for sure here if that direction can hold overnight. Today during the day was the first Easterly interlude in the surface winds here in the last few days!

Is this what you are looking for ?

darkman2 · 29-11-2010 6:33pm

Those showers should be turning increasingly to rain at this stage in the East near the coast. Won't be till sunrise at the earliest that rain will turn back to snow. It's going to get very messy with melting continuing on the East coast as temperatures rise just above freezing tonight.

lucernarian · 29-11-2010 6:35pm

Having looked at the 850-1000 hPa thickness charts from the NAE Model, it would appear that coastal regions south of Drogheda will more likely than not see sleety snow and rain until about 6am. 10km inland in Leinster can expect more snow, albeit amounts may vary widely.

The GFS model is more pessimistic and suggests the transition will be later in the morning for the likes of Dublin city itself. Many More inland areas should see quite a lot of the white stuff by tomorrow night though!

pistolpetes11 · 29-11-2010 6:43pm

darkman2 wrote: »

Those showers should be turning increasingly to rain at this stage in the East near the coast. Won't be till sunrise at the earliest that rain will turn back to snow. It's going to get very messy with melting continuing on the East coast as temperatures rise just above freezing tonight.

Is there not -8 uppers over the country for most of the night which are due to drop to -10 around 2am, with dew points to drop from around 9pm, as well as a 516 dam line over the country also ?

29-11-2010 6:44pm

darkman2 wrote: »

Those showers should be turning increasingly to rain at this stage in the East near the coast. Won't be till sunrise at the earliest that rain will turn back to snow. It's going to get very messy with melting continuing on the East coast as temperatures rise just above freezing tonight.

Snowing lightly in Cabinteely.

pistolpetes11 · 29-11-2010 6:50pm

darkman2 wrote: »

Those showers should be turning increasingly to rain at this stage in the East near the coast. Won't be till sunrise at the earliest that rain will turn back to snow. It's going to get very messy with melting continuing on the East coast as temperatures rise just above freezing tonight.

Seem to be showing that you are correct on the predictive radar :mad:

tonyrich1 · 29-11-2010 6:52pm

does anyoe foresee these showers going as far south as north wexford. ??

Trogdor · 29-11-2010 6:53pm

pistolpetes11 wrote: »

Is there not -8 uppers over the country for most of the night which are due to drop to -10 around 2am, with dew points to drop from around 9pm, as well as a 516 dam line over the country also ?

Dewpoints are actually progged to rise slightly overnight and then fall back tomorrow morning again, vernight is the main problem area really..

Ps, i wouldn't pay any attention what so ever to what any radar predicting precipitation type is saying;)

pistolpetes11 · 29-11-2010 7:08pm

trogdor wrote: »

Dewpoints are actually progged to rise slightly overnight and then fall back tomorrow morning again, vernight is the main problem area really..

Ps, i wouldn't pay any attention what so ever to what any radar predicting precipitation type is saying;)

DPs for 12

Looks good for me in Newbridge but on most of the East coast they look like there at 0'c bar the small section over the isle of man.

Would you be expecting the showers to rise the DPs ?

Trogdor · 29-11-2010 7:22pm

pistolpetes11 wrote: »

DPs for 12

Looks good for me in Newbridge but on most of the East coast they look like there at 0'c bar the small section over the isle of man.

Would you be expecting the showers to rise the DPs ?

https://us.v-cdn.net/6034073/uploads/attachments/181192/137228.png

That would depend on what the showers consist of:p If we had a constant stream of heavy snow showers i reckon evaporative cooling from the falling snow may keep the temperature and dewpoint the right side of marginal for coastal areas however if we get cold rain it will do no good really. Areas a bit inland from the coast I'd say are a dead cert for snow though.

Redsunset · 29-11-2010 7:22pm

Met Eireann says as far as they can see there is no end in sight to this weather,

Just reported on RTE NEWS now

Radharc na Sleibhte · 29-11-2010 7:31pm

Does anyone know when the weather/temperature is set to return to normal?

Trogdor · 29-11-2010 7:37pm

MikeySligo wrote: »

Does anyone know when the weather/temperature is set to return to normal?

From friday evening onwards, things should warm up a bit from the deep cold that will be present of the next few days. But maybe "warm up" isn't quite the best description as it will still be below average for the time of year.

linguist · 29-11-2010 7:46pm

There appears to be a definite thaw going on here in Donabate at the moment.

traco · 29-11-2010 8:03pm

There seems to be a thaw in portmarnock also at the moment (19:00).

There was rain sleet around 3pm and temps bumped to 3c.

In the last few hours there has been hail or graupel if thats the technical term, mix of hail and fine powder.

linguist · 29-11-2010 8:05pm

Watched Gerry Murphy on RTE...did anyone else? There appears to be a front coming with the snow behind it. Did anyone else spot that? Cold or warm front then?

Radharc na Sleibhte · 29-11-2010 8:26pm

trogdor wrote: »

From friday evening onwards, things should warm up a bit from the deep cold that will be present of the next few days. But maybe "warm up" isn't quite the best description as it will still be below average for the time of year.

Thanks Trogdor.
Sounds good to me.
Love the snow.
Feckin hate the ice.

pistolpetes11 · 29-11-2010 8:35pm

MikeySligo wrote: »

Thanks Trogdor.
Sounds good to me.
Love the snow.
Feckin hate the ice.

The Met said on there forecast they see it lasting into next week ,

Seems to be a slight breakdown at 90hrs but there is always at least -4 uppers and it looks to be getting colder at the end of the run , but this is well into the FI territory

isle of man · 29-11-2010 8:36pm

i think most of the charts are over adding rain/snow etc.
well they are for IOM.
we have had nowt wet for over 24 hours now.
slight dribble up north for 10 mins at about midnight last night.

Temps today have been a lot warmer then the last few days.
There ment to be giving more rain/snow for tonight, but my faith in all the charts i have seen is not vary high at this time, as they have been wrong for the past 3 days for us.
which is a pitty as they are normaly 75-99% right.

clear skys at the mo, rain/snow ment to be at around midnight tonight, but as these showers just apper on the charts from no where i wont hold my breath.

I see the slip stream will be changing by friday which will end this cold weather for a little bit.

Did i see a wind chart posted that had high winds for us on tuesday. That could cuase some major drfting

hotwhiskey · 29-11-2010 8:39pm

This is looking good! the current system across the UK is growing intensity.

Eastcoastryan · 29-11-2010 8:40pm

trogdor wrote: »

That would depend on what the showers consist of:p If we had a constant stream of heavy snow showers i reckon evaporative cooling from the falling snow may keep the temperature and dewpoint the right side of marginal for coastal areas however if we get cold rain it will do no good really. Areas a bit inland from the coast I'd say are a dead cert for snow though.

Hey Trogdor, quick question.. just had a look at your site and it shows the wind direction as NW, is it not supposed to be Easterly? I've noticed the DP is the wrong side of marginal for snow here. Just wondering, are winds supposed to change direction this evening and what effect would this have on temps and Dew Point?

I want more snow and Met Eireann are teasing me with their weather warnings, whats your thoughts on the next 24 hours??

TheMilkyPirate · 29-11-2010 8:41pm

Right so sleety rain if anything in wexford town tonight and snow tomorrow, Am i right?

I'm being very imby i know but i never usually am and haven't seen wexford mentioned once tonight yet so just curious as my girlfriend is due to travel to waterford.

delw · 29-11-2010 8:44pm

M2 bouy dp has gone from -0.8 to -0.6,a slight rise

darkman2 · 29-11-2010 9:08pm

I see posters keep asking question so I think we should deal with this here.

Tonight there will be rain and sleet in coastal counties. Some warmer air has arrived after getting mixed up in the flow from the East. Temperatures and dew points will rise tonight. Lying snow will thaw. Inland a partial thaw will occur. In the morning after 6am snow will return to coastal counties and start to accumulate again.

Tonight snow may occur 40 or more miles inland and on high ground.

Just thought I would put this here because of the number of questions and to avoid confusion.

Basically if you are near or on the coast don't expect anything tonight.

isle of man · 29-11-2010 9:15pm

thanks for clearing that up.

even though i hate to read it.

pistolpetes11 · 29-11-2010 9:16pm

Just incase people are not reading the main reports thread, weathercheck just posted an up on whats happening at the moment

Weathercheck wrote: »

Update

Basically what is happening wrt a thaw and the possibility of marginality in the snow is that as the east winds pick up which are steadily they are whipping up air from the Irish sea which is quite mild. This is tempered as it crosses land. It will mean that temperatures won't dip much below what they are now for the east coast for the rest of the night. Persistent precipitation and the heavier will drop the temp and stop any thawing that is occurring as a result of the temperatures being around 0-2c.

The band over the north UK is gathering and this is the band that is expected to pep up further as it hits the Irish sea. This will then hit the Irish sea coasts from around 3am. Until then light showers will pepper the coast, those which are heavier will contain hail and snow, lighter ones will contain graupel, sleet and rain.

Now as the main band (occlusion) hits tomorrow any precip will readily turn to powder snow as the morning progresses and very cold and dry air will push in behind the front, which origins from Siberia. From Tuesday afternoon any showers will consist of snow or snow grains and will stick to pretty much anything. There will be decent showers of snow hitting the east coast right up until Thursday afternoon.

During Thursday night as a slack low approaches from the Northwest, Ireland looks like remaining in a COL (an area between high and low pressures) winds will be non-existent and conditions over head and on the ground will allow for an extremely cold night, with records surely to be broken in some areas. Now a slight change in synoptic could change this, but temperatures could dip to as low as -15c.

Wednesday - Thursday - Friday look like having dramatically cold maxima and minima.

Friday - Weekend.

Sees a weak system from the Atlantic move in, upper air tempatures will rise dramatically but this will have little impact on the surface with temperatures anticipated to struggle to get above 0 or 1c through the period.

A truly exceptional freeze, and if the next few days work out, sure to rival any other in the last 50 years to affect the Dublin region and eastern seaboard.

Cold Spell Chart, Forecast Analysis & Warnings- 29/11/2010 onwards

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