Frost, Ice and Possible Snow Showers this Weekend (13th-16th Dec 08)

JanuarySnowstor

Models are now starting to upgrade the chance of a serious snow event for the SouthWest of Ireland this Saturday.
The latest 18z run has temps of 0-2 all day Sat and Sun with -7 showing Sat night over Kerry
The beeb 5 dayer is even on board if you check out Sat for Cork airport

Will good ol Gerry mention the word shleeet:D

Snowbie

Just looked at the beeb 1 just there with Rob McElwee and precip charts indicating rain over Ireland even preceeding the front but 'Heavy snow' warning for UK yet again.

JanuarySnowstor

Did you not see the West of Ireland laden with snow.
This event (like all great snow events in history) has popped out of the blue.
Im certain the West will see heavy snow on Saturday.
As is the norm the Irish Met will lag behind

Danno

Indeed... the BBC have snow for Kerry... looks kinda pretty!

Snowbie

JanuarySnowstor wrote: »

Did you not see the West of Ireland laden with snow.
This event (like all great snow events in history) has popped out of the blue.
Im certain the West will see heavy snow on Saturday.
As is the norm the Irish Met will lag behind

no?? Do you want to post what you have seen from the 18z so we all see what you are referring to

arctictree

JanuarySnowstor wrote: »

Models are now starting to upgrade the chance of a serious snow event for the SouthWest of Ireland this Saturday.
The latest 18z run has temps of 0-2 all day Sat and Sun with -7 showing Sat night over Kerry

-7c?? That's mighty cold for the SW

Snowbie

Danno wrote: »

Indeed... the BBC have snow for Kerry... looks kinda pretty!

Is this the west laden with snow. Look at the precip in blue over NI and at -1C??? or am i reading something wrong here

nacho libre

i saw what he/she is talking about too, and i'm confused. the question is does that stay where it is or come in over land because i remember a couple of weeks ago the bbc charts showed loads of snow about 200 miles to the north west of Ireland and of course nothing came of that.

JanuarySnowstor

Snowbie wrote: »

no?? Do you want to post what you have seen from the 18z so we all see what you are referring to

I dunno how to post links but it shows heavy ppn moving South over Western Ireland on Saturday with temps at 1C, sub 528 dam air and -5 uppers.
It's a certainty if the charts dont change but mostly for the West and South

Couple this with the beebs forecast just gone and the 5 dayer showing snow for Cork
Type in Cork Airport

Snowaddict

These are the charts that JS is referrring to (in the next post below)

SA.

Snowaddict

The charts which present a risk of wintriness to many parts at the weekend, based on GFS 12Z.



Followed by this one:



And this chart:



And Sunday Afternoon



And Saturday Night Maxmium Temps:

nacho libre

Snowbie wrote: »

Just looked at the beeb 1 just there with Rob McElwee and precip charts indicating rain over Ireland even preceeding the front but 'Heavy snow' warning for UK yet again.

but on the precipitation chart for late saturday it showed tons of snow just off the west coast of ireland.

Danno

The -7 is there allright. Funny how the GFS is only showing this up now...

Snowbie

JanuarySnowstor wrote: »

I dunno how to post links but it shows heavy ppn moving South over Western Ireland on Saturday with temps at 1C, sub 528 dam air and -5 uppers.
It's a certainty if the charts dont change but mostly for the West and South

Couple this with the beebs forecast just gone and the 5 dayer showing snow for Cork
Type in Cork Airport

Of course when there is a chance of snow, i always sit and take note but with the variables you posted above maybe are marginal for lower ground. The lads in Kerry at height may have something better. Here is the precip chart but snowline going for 200m atm. Might be of interest closer the time

nacho libre

it will be interesting to hear what the RTE radio forecaster has to say at 12.

Snowbie

nacho libre wrote: »

but on the precipitation chart for late saturday it showed tons of snow just off the west coast of ireland.

Yea seen that but that usually indicates showers

Edit: the fax has series of troughs in the polar maritime airstream.

kerry1960

JanuarySnowstor wrote: »

Models are now starting to upgrade the chance of a serious snow event for the SouthWest of Ireland this Saturday.
The latest 18z run has temps of 0-2 all day Sat and Sun with -7 showing Sat night over Kerry
The beeb 5 dayer is even on board if you check out Sat for Cork airport

Will good ol Gerry mention the word shleeet:D

JS ,no offence mate ,but snow and -7 in Kerry , in Dec , naw , i'll believe it when im shivering in it .........:)

nacho libre

Snowbie wrote: »

Yea seen that but that usually indicates showers

still a bit confused. sorry.:o
do you mean snow showers or do you mean the precipitation would be in the form of showers of rain once they hit land?

if that's the case, one thing i don't understand is, why would the bbc chart be laden with snow when it's from that direction(off the west coast), also given that the atlantic usually would modify any cold airstream from a westerly or north westerly direction enough to ensure the air temperatures would be too high for snow off the west coast of ireland. i know sometimes we get snow if the source is way up in a cold region of the north atlantic(like greenland) but this doesn't seem to be the case this time.

Danno

The cold is there allright as the very strong diving jet pushes this down from Greenland over a very short spell of time = less modification...




Also, a virtually uninturrupted stream of sub zero dew point air...

danni2

Is this snow event only going to effect southwestern Ireland, or will other parts be effected as well?

Danno

Areas west of a line from Derry to Wexford look like being affected... although, the charts are only showing this today, so the finer details will not be seen until Friday night I would imagine. It could turn out to be nothing yet - hence the word possible in the thread title.

I also suggest that the thread title be changed to Saturday Night/Sunday Morning...

Snowbie

nacho libre wrote: »

still a bit confused. sorry.:o
do you mean snow showers or do you mean the precipitation would be in the form of showers of rain once they hit land?

That graphic indicated snow showers and the fax i posted would back that up with the troughs or organised bands(subject to change of course)

if that's the case, one thing i don't understand is, why would the bbc chart be laden with snow when it's from that direction(off the west coast), also given that the atlantic usually would modify any cold airstream from a westerly or north westerly direction enough to ensure the air temperatures would be too high for snow off the west coast of ireland. i know sometimes we get snow if the source is way up in a cold region of the north atlantic(like greenland) but this doesn't seem to be the case this time.

Tbh, thats the first time i have seen the graphic indicating the whiteness this far south this year out west in the Atlantic. What usually tends to happen, when a trough moves through in polar maritime air, the air tends to chill more behind it. As the air is sourced more GL, the upper air or cold air aloft would create instability over warmer seas and some potent troughs arise.

As with intensity of a shower, the precipitive cooling would most likely result in snow reaching lower levels even in +4C air temp to begin with. Most likely the UKMO model recognises that and produced the graphic for it albeit not accurately i think. That graphic just seems to plaster shed loads of snow out west of Ireland indicating showers and the nature of showers is you just don't know where they will fall. No frontal stuff is charted around for that time.

lostexpectation

got any interesting fact or or figure or charts or maps on heat bloom reducing snow sticking in dublin etc?

Deep Easterly

JanuarySnowstor wrote: »

Im certain the West will see heavy snow on Saturday.

Will hold you too that.

JanuarySnowstor

06z coming out and still showing heavy snow for the Western half of the country. East looks mainly dry

JanuarySnowstor

JanuarySnowstor wrote: »

06z coming out and still showing heavy snow for the Western half of the country. East looks mainly dry

I don't know what GFS you are looking at but if it is the same as mine,I think you need glasses.
-5 850 air off a maratime atlantic [polar maratime air] with temps of 3 to 7 c...
Thats rain unless you are climbing Mt Brandon or Carrantouhill.

JanuarySnowstor

Where did you get the 3 -7?????

7 on the coast-it's the undercut of that surface air that really kills it.Always repeat always when looking for snow look at the upstream surface air temp.
3c in clare and 2 c well inland 4c in kerry 2c in NW Cork with at best 0c dewpoints.

It's all there on the map.

-5c 850 air is not enough for snow in Ireland below 2500ft.

Come on now-be a tad realistic

JanuarySnowstor

I would be confident that everywhere above about 500feet will get snow.
It may not lie, though i think it will.
I'm in Cork under the 2 anyway:D

Of course it could stay dry

ronbyrne2005

http://www.snowathome.com/index.php

How much would it cost to build a snow machine here in Ireland? Compressor and all that sh1te?

maquiladora

Possible Major Snow Event? I just don't see anything even close to that. Just looks like rain and maybe a bit of sleet on high ground....

Snowbie

@JS.

According to the hi res GFS, snow is very unlikely at lower levels in the west and SW.
Above 400m there is only a 45- 50% chance. If anything this is a downgrade but i'm not convinced this was ever going to materialise in the first place.

I will change your thread title as it is misleading to possible snow in west and SW from 'possible major snow event Saturday' as the air is cold sourced but polar maritime it still will be chilly and with precip around a chance is there.

A major snow event is only such when snow falls and settles at lower levels. Mountainous areas are always at risk from major snow events and is somewhat a re-occurance time after time.

Also for future reference, if you can link to an image and describe what you see instead of most here posting links for you it be great. Use the [IMG][/IMG] tags to insert an image

nacho libre

from met.ie:
Temperatures through the weekend will only be in low single figures during the day and the showers (this next bit may or may not be factual;) ) will be of sleet or snow in most aeras, with significant accumulations likely. A spell of more general rain is likely to develop during Monday. The cold weather is then set to continue into the middle of next week, although it wont be quite as cold as the weekend.

so it looks like the wait for snow goes on:(

JanuarySnowstor

Dont agree with title change myself
12z upgrades both temp and ppn
Snow looks a certainty imo

Snowaddict

The latest GFS run is a an upgrade for snow potential for many parts at the weekend, I know Met Eireann have not mentioned anything much but I really though I should post these charts from the 12Z.
They are very interesting to say the least, GFS projecting snow depts of 5 and 6cm in several higher ground areas, within the snowline down to below 100m in eastern areas, this could be something to watch indeed.



And this chart:

ninebeanrows

I think i might throw up.

GFS shows heavy snow over much of Ireland Saturday night/ Sunday.

I might just get sick.. off out of the country for the weekend.

Snowaddict

Weathercheck wrote: »

I think i might throw up.

GFS shows heavy snow over much of Ireland Saturday night/ Sunday.

I might just get sick.. off out of the country for the weekend.

But Met Eireann have said nothing about it Weathercheck.

I'm still a bit skeptical to say the least, although there does seem to be quite a widespread and substantial risk going on the latest run, which is only 48 hours out from the timeframe.

ninebeanrows

Snowaddict wrote: »

But Met Eireann have said nothing about it Weathercheck.

I'm still a bit skeptical to say the least, although there does seem to be quite a widespread and substantial risk going on the latest run, which is only 48 hours out from the timeframe.

Yes of course it might change yet but i would say things are shaping up well for snow over Ireland this weekend.

Dewpoints/ Temperatures/850hpa temps/ Thicknesses all look favorable for snow.

I haven't being saying much as i had hoped it would edge on the other side of marginal but its edged on the snow side of marginal and it only 2 days away.

Obviously await the UKM and other outputs but i would expect warnings will be out tomorrow morning from the MET.

:eek::(

It's a little bit better than the earlier runs.
I'd bring the snow level down to 800ft asl on this one.
The precip if very heavy might bring it lower than that well inland.
Rain for coastal districts.

I must say I've a lack of faith in the GFS even at this short time out due to it's changing all the time!

ninebeanrows

Why arent you guys getting excited!

You have everything on your side, i'm not going be here for god sakes! It's gonna snow :pac::(

I want the snow to be on the ground come Monday afternoon.

Not often these charts play ball.

Snowaddict

Weathercheck wrote: »

Why arent you guys getting excited!

You have everything on your side, i'm not going be here for god sakes! It's gonna snow :pac::(

I want the snow to be on the ground come Monday afternoon.

Not often these charts play ball.

Weathercheck, you just read my mind posting that chart.

I've gone through all 20 perturbations and there is substantial agreement amongst all 20 perturbations of 850HPA's of at least -6, to even -8 over many parts of Ireland at the weekend.

Many of them also suggest snowfall as shown by Weathercheck.

I would give it 50% in favour at the moment, going on the 12Z GFS.

However, this is subject to change.

Supercell

Wow, what an upgrade!, here was me thinking not a snowballs chance in hell..and then here we are, lovely stuff!!

Snowaddict

Supercell wrote: »

Wow, what an upgrade!, here was me thinking not a snowballs chance in hell..and then here we are, lovely stuff!!

Do you think it will actually materialse Supercell?
I mean its a major upgrade for us, but it is only one run and has the peak potential been shown too early, 48 hrs ahead?

Supercell

Snowaddict wrote: »

Do you think it will actually materialse Supercell?
I mean its a major upgrade for us.

Well, it looks like i might see some snow falling, maybe even lying (30% risk I'd guestimate).
At sea level maybe a few hours of wet snow, cant really see any real cold that would allow for lying snow there. That said it is mid December, so who knows

patneve

looking at those charts I'd guess snow over 100-200 metres asl with mixed precipitation below

JanuarySnowstor

Should my title have been changed and downgraded i wonder ?
Latest fax laden with troughs.
If its Gerry on the tv tonight expect some sleeet on mountains

patneve

JanuarySnowstor wrote: »

Should my title have been changed and downgraded i wonder ?
Latest fax laden with troughs.
If its Gerry on the tv tonight expect some sleeet on mountains

one day we will get our revenge on gerry. One day he will predict some sleety rain, and the next day there will be a blizzard with 20 cm accumulations on the whole island...and everyone will laugh in his face:rolleyes:

MUSEIST

patneve wrote: »

one day we will get our revenge on gerry. One day he will predict some sleety rain, and the next day there will be a blizzard with 20 cm accumulations on the whole island...and everyone will laugh in his face:rolleyes:

ahhh thats a bit harsh:D

Supercell

I'm not holding my breath lads..unless that (imaginary) gaff up on Sally Gap comes on sale any time soon

Snowaddict

Supercell wrote: »

I'm not holding my breath lads..unless that (imaginary) gaff up on Sally Gap comes on sale any time soon

I very much agree with you there, although the maps on the 5.55pm forecast showed max temps of 5c and 3c for Sat and Sun respectively, with wintry showers, however the forecaster went no further than Friday...

JanuarySnowstor

Well Gerry didn't mention the word snow which is very odd for him
Looks like its JS against Met Eireann
Imo a disgraceful but typical forecast