Significant snow Thursday Night/Friday/Saturday

maquiladora

maquiladora wrote: »

How reliable are dp predictions 48 hours from an event like this?

The source is very low dp friendly,it's the mixing en route that will cause the problems.

You often see people post that the door is open to the cold-well thats a very good analogy.
You leave the door open long enough and you are wasting your time leaving the radiators on.
In this case the radiators are the atlantic systems carrying some heat with them as they envelope into the cold feed.
The longer the door is fully ajar (the one at the end of the hall),the greater the likelyhood that the room whose door is also open will get really cold.

In that analogy,the hall is the atlantic and we are the room.
Both doors are open but they are going to slam shut,it's a question of when.


Oh I might add,the radiators burst a lot due to poor maintainence,thats the rain

maquiladora

Deleted User wrote: »

The source is very low dp friendly,it's the mixing en route that will cause the problems.

You often see people post that the door is open to the cold-well thats a very good analogy.
You leave the door open long enough and you are wasting your time leaving the radiators on.
In this case the radiators are the atlantic systems carrying some heat with them as they envelope into the cold feed.
The longer the door is fully ajar (the one at the end of the hall),the greater the likelyhood that the room whose door is also open will get really cold.

In that analogy,the hall is the atlantic and we are the room.
Both doors are open but they are going to slam shut,it's a question of when.


Oh I might add,the radiators burst a lot due to poor maintainence,thats the rain

Bravo!

arctictree

This time tomorrow we should know for certain if we will get a front crossing us on Thurs night. UKMO charts are really pushing this scenario.

I wonder if Snowbie is reading this?!!

A

nacho libre

Sierra Oscar wrote: »

I wonder how much we could get down around Limerick\North Tipp?

if we get a polar low or even a band of troughs, spreading southwards from the northwest, places in munster that don't normally don't see snow will get some.

places in these scenarios that are likely to miss out are the east and south east. so tobeconfirmed you should drive to North Tipperary;)

nacho libre

nacho libre wrote: »

if we get a polar low or even a band of troughs, spreading southwards from the northwest, places in munster that don't normally see snow will get some.

places in these scenarios that are likely to miss out are the east and south east. so tobeconfirmed you should drive to North Tipperary;)

My rule of thumb is very simple.
Would you get rain in summer or at any other time from the atlantic showers in a north westerly?
Yes you would so I think Limerick and north tipp should get a covering of snow and certainly a lot more than I will see probably.

Gonzo

is there a chance of us in Meath seeing any snow from this?

Gonzo if you had snow from that post Xmas episode a few years ago then yes.
In fact I would say yes.
I'm hopefull for every one but less hopefull for lying snow down my way in theory but I simply dont know because like the rest of ye,I know the showers will be big and plentifull but I can only guess the rest.

The wind will be strong at times so that is a plus.
It's a minus too though as it will shorten the time a shower stays with you.
Enjoy anyhow whatever you get,tiz better,much better than last year.

Gonzo

definitely, any snow that I get from this is a plus to the snow I already got beginning of January and who knows there could be more cold snaps after this one. So far this winter Ive had 2 Ice days and 1 snow day, thats much better than any winter since 2000.

arctictree

Gonzo wrote: »

definitely, any snow that I get from this is a plus to the snow I already got beginning of January and who knows there could be more cold snaps after this one. So far this winter Ive had 2 Ice days and 1 snow day, thats much better than any winter since 2000.

2 ice days - are you sure?

AFAIK, an ice day is when your max daily temp is below zero. They are very rare in these parts.

maquiladora

Met warning slightly different from the one posted on Page 3 :

A cold snap will develop over Ireland for Thursday, Friday and much of the Weekend. Wintry showers of hail, sleet and snow are expected at times on Thursday and Friday, with Ulster, Connacht, northern Counties of Leinster and also West Munster most at risk of some significant snowfall, but other areas should see a dusting of snow too. The days and nights will be very cold with any snow lying. Showers should become well scattered later Friday night and for Saturday, and a partial thaw is likely in any sunshine. But present indications suggest that a spell of heavy rain will move up over the country on Saturday night and early on Sunday, falling as sleet and snow for a time, mainly on high ground.

Gonzo

arctictree wrote: »

2 ice days - are you sure?

AFAIK, an ice day is when your max daily temp is below zero. They are very rare in these parts.

Maybe just 1 then, it was the Friday everyone finished work for the Christmas, we had -7C the night before and the temperature rose to about 0C around 1pm and fell again subzero after 3pm with a really hard frost that never melted till Friday Night. Hardest frost we had in a long time. If it wasnt an ice day it was certainly very close to one and looked the same as the ones we got in the 80s.

Trogdor

Gerald Flemming on the 2:55 forecast didn't even go past tomorrows weather, must be very cautious in there about Thursday night onwards. When he ran the temp animation for tomorrow though we got down to 3C here in the East and North-East by 15:00 with snow showers, and tomorrow will be the warmer day!

darkman2

hmmm

maquiladora

No drastic change with the 12Z it seems.

Trogdor

hmm indeed:(, I'd like to see a min temp chart though. Dewpoints look awful givin the conditions.
http://www.wetterzentrale.de/pics/Rtavn4810.png

darkman2

Dew points drop back quickly though below freezing by 18:00 on Friday

Here is a min chart

http://expert.weatheronline.co.uk/cgi-bin/geturl/daten/profi/en/2008/01/30/basis12/enen/tmin_08020112_3012.gif?00b28e3180cce97e05acac2b61642ce5

darkman2

http://www.wetterzentrale.de/pics/Rtavn10217.png

Sunday could yet be interesting as an occluded front passes through. Sleet and rain but snow on the back edge?

darkman2

darkman2 wrote: »

Dew points drop back quickly though below freezing by 18:00 on Friday

Here is a min chart

http://expert.weatheronline.co.uk/cgi-bin/geturl/daten/profi/en/2008/01/30/basis12/enen/tmin_08020112_3012.gif?00b28e3180cce97e05acac2b61642ce5

Those mins are fine in the east as long as theres precip in them.
It's not the same as a marginal easterly in that you are getting a wind off the land not the warmer sea.

Down here it's not DP's I'm worried about as the flow will be passing through the wicklow mountains.It's a possible lack of actual precipitation.

darkman2

Deleted User wrote: »

Those mins are fine in the east as long as theres precip in them.
It's not the same as a marginal easterly in that you are getting a wind off the land not the warmer sea.

Down here it's not DP's I'm worried about as the flow will be passing through the wicklow mountains.It's a possible lack of actual precipitation.

I dont think precip will be a problem judging by those charts. Looks frontal instead of showery. This is backed up by the tiny wamer sector.

ninebeanrows

Well GFS is firming up and it aint bad with precip out to 48hrs

By golly it could be snow nirvana on Friday or there could be tears..

Bad points;

Incursion of -3/-4c 850hpa in association with occlusion

Dewpoints rise to 0/1c when the precip is at the heaviest.

Positives.

Wind of the land, not off the sea.

Lots of Heavy Precipitation

Precip moves in after sharp frost, temperatures down to -2c.

Precip will start off as snow for sure


Conclusion

Friday reminds me of one day yonder in 2001. February........27th maybe!

That was marginal but came off.

This could well be the single snowiest day across Ireland since then.

Why i favour snowfall is due to the fact that the only thing that could scupper this is the dewpoints rising above freezing, if they are at 0c with such heavy precip there will be snow.

If this were to come off with snowfall i would expect the East to be severely disrupted on Friday with upto 9 inches of snow locally and above 3 inches over a wide area.

Trogdor

Deleted User wrote: »

Those mins are fine in the east as long as theres precip in them.
It's not the same as a marginal easterly in that you are getting a wind off the land not the warmer sea.

Down here it's not DP's I'm worried about as the flow will be passing through the wicklow mountains.It's a possible lack of actual precipitation.

It wouldn't stick with those temps though, would it? I'd really love to see some lying snow down here. It's been a very long time:(.

rc28

Weathercheck wrote: »

Well GFS is firming up and it aint bad with precip out to 48hrs

By golly it could be snow nirvana on Friday or there could be tears..

Bad points;

Incursion of -3/-4c 850hpa in association with occlusion

Dewpoints rise to 0/1c when the precip is at the heaviest.

Positives.

Wind of the land, not off the sea.

Lots of Heavy Precipitation

Precip moves in after sharp frost, temperatures down to -2c.

Precip will start off as snow for sure


Conclusion

Friday reminds me of one day yonder in 2001. February........27th maybe!

That was marginal but came off.

This could well be the single snowiest day across Ireland since then.

Why i favour snowfall is due to the fact that the only thing that could scupper this is the dewpoints rising above freezing, if they are at 0c with such heavy precip there will be snow.

If this were to come off with snowfall i would expect the East to be severely disrupted on Friday with upto 9 inches of snow locally and above 3 inches over a wide area.

it's a pity it isnt happening on thursday night as then there would be a chance i wouldnt have to do the irish mock paper! (our school closes very easily when there's snow and ice as the road leading to it is never gritted and becomes a serious skating rink-in one cold snap i saw 3 separate minor accidents)

Paddy.1

Weathercheck wrote: »

If this were to come off with snowfall i would expect the East to be severely disrupted on Friday with upto 9 inches of snow locally and above 3 inches over a wide area.

And the West?

Supercell

That Friday occlusion is looking better and better (12z ensembles are interesting for sure), it all hinges on that I reckon, at least here in the east.
If and its a BIG IF, it doesnt peter out by the time its around Dublin and Wicklow snowfall amounts could be semi decent with 5cm in places and maybe up to 10cm higher up.

Donegal/Mayo /Sligo could all have a good 10-20 cm in places by Saturday (even if the occlusion doesnt materialise).
I also suspect some people on higher ground could have a nice snowy breakdown over the weekend too

Paddy.1

Paddy.1 wrote: »

And the West?

Wc is clever that way.
He already knows that the west will have fallen into the atlantic under the weight of the snow back there so it wont matter at this stage.
He just didnt want to frighten you.
Damn now I have you petrified.

Paddy.1

Widespread, or hit and miss? Convetion may occur even inland as occlusion moves down.
http://www.wetterzentrale.de/pics/brack1.gif

Showers becoming confined to coastal regions by afternoon.

http://www.wetterzentrale.de/pics/brack1a.gif

Eventful couple of days ahead, and going by the above charts, almost set in stone for the northern half of Ireland. Anticipating further tweeks.

darkman2

http://www.meteociel.com/ukmo/run/UW48-7.GIF


No such problems with a warm sector on the UKIMO but less precip.


Sunday looking more and more interesting too;)

Supercell

Updated fax charts not so good for East coast Ireland

http://www.wetterzentrale.de/pics/brack0a.gif

http://www.wetterzentrale.de/pics/brack1.gif

Looks to have moved the snow over to mainland UK.
Going to be a nowcast thing by the looks, just hope there are still troughs forecast this time tomorrow night.

Neamhshuntasach

So if it does actually snow. What are you all gonna do? Build snowmen? Make snow angels?

Supercell

Day off work, take pictures, get drunk.

The best weekdays are snow days.

Ohh, and I'll make a snowman too