Cold Spell Discussion (Ireland): Cold/Frosty/Icy with Snow for some

little bess

Oh if only we had some precip, dp's at m2 now -0.1 !

Saganist

Quick question. Are easterlies enough to produce some new convection out at sea or do we need a more NE. ?

fontenoy7

Daniel2590 wrote: »

Are you able to get any pics? :O

Where in the coast??

JanuarySnowstor

The 'EVENT' tomorrow for the South will probably be decided by dewpoints.
It could be a great snow event for us but it is marginal
The one pity is that we haven't had a decent feed from the UK over the last few days to cool things down.
We are basically relying on a deep cold pool from the atlantic.
The models from now on aren't really any help, it's now down to radar & lamp post watching

Weathering

Pic of bangor atm pic.twitter.com/pkcm19HO

Trotter

What do I need to be watching for here in Waterford now?
I'm keeping an eye on the dew points and temp along with the rain today radar.

Am I right in saying our best shot here on the Waterford coast is 1am Monday morning to 7am Monday morning if the DP is below 0?

Rebelbrowser

JanuarySnowstor wrote: »

The 'EVENT' tomorrow for the South will probably be decided by dewpoints.
It could be a great snow event for us but it is marginal
The one pity is that we haven't had a decent feed from the UK over the last few days to cool things down.
We are basically relying on a deep cold pool from the atlantic.
The models from now on aren't really any help, it's now down to radar & lamp post watching

Im getting more worried the nearer we get. Thought it would be generally colder by now... I'll stick to my guns though and keep calling it a snow event.

channaigh

My car is frozen now ground getting slippy. Thought I seen a flake but it was only ash from my smoke. We live in hope in kk

Rebelbrowser

Trotter wrote: »

What do I need to be watching for here in Waterford now?
I'm keeping an eye on the dew points and temp along with the rain today radar.

Am I right in saying our best shot here on the Waterford coast is 1am Monday morning to 7am Monday morning if the DP is below 0?

Would say so - and if the precipitation is there...

Trotter

Rebelbrowser wrote: »

Would say so - and if the precipitation is there...

Looks like a heavy band of precip coming across the southern half of the country from about 7pm tomorrow night. I'll book my seat at the lamp post.

Rougies

Saganist wrote: »

Quick question. Are easterlies enough to produce some new convection out at sea or do we need a more NE. ?

yeah fine once the temps are all good. You want over about 150km of "fetch".

Tom Cruises Left Nut

Trotter wrote: »

Looks like a heavy band of precip coming across the southern half of the country from about 7pm tomorrow night. I'll book my seat at the lamp post.

Welcome back man, glad ya kept the faith !

rc28

Rougies wrote: »

yeah fine once the temps are all good. You want over 150km of "fetch" at least.

Yes the most important thing is the length of the fetch - this is why a north easterly is better than a straight easterly for the bulk of the Leinster coast - the showers come down from around the Isle of Man area and hit from south louth all the way down to Wicklow. However, a straight easterly brings a shorter sea fetch and it seems that Anglesey spoils things (just like the Isle of Man shadow in 2010 did for certain areas e.g. Bray!).

Rougies

rc28 wrote: »

Yes the most important thing is the length of the fetch - this is why a north easterly is better than a straight easterly for the bulk of the Leinster coast - the showers come down from around the Isle of Man area and hit from south louth all the way down to Wicklow. However, a straight easterly brings a shorter sea fetch and it seems that Anglesey spoils things (just like the Isle of Man shadow in 2010 did for certain areas e.g. Bray!).

Just to add to that, you can see the Isle of Man shadow in full effect right now. If I lived in Portaferry, Co. Down I'd be rowing out to the IOM with a very large bomb right now!

Trotter

t|nt|n wrote: »

Welcome back man, glad ya kept the faith !

I could smell a low DP with potential precip and said to meself.. Theres gotta be some mention of Waterford? Surely?

That and the missis is out. I cant be accused of being addicted to weather watching if Im not being watched weather watching now can I?

H2UMrsRobinson

Ok that's it I'm off to de pub. Can't take anymore.

Rougies

coffee to go wrote: »

Photo of the Wicklow Gap today at about 3pm. Road was surprisingly clear both ways. -2ºC at the top but felt waaaaaaay colder. Occasional light flurries while we were there. I hear the Sally Gap was much worse.

Rotated version
http://imgur.com/Vi2m9Nu

John.Icy

Saganist wrote: »

Quick question. Are easterlies enough to produce some new convection out at sea or do we need a more NE. ?

North Easterlies anyday for the East. Easterlies are usually too dry for most. Streamers only kick off at certain points, they wont just form out of nothing. The IOM is our streamer machine. In an easterly, it's the north and south tips that get streamers going, like tonight, and in a north easterly its on the west and east tips of the IOM they fire up from, like 2010. With a NE there's a longer sea fetch, so streamers are more intense and longer lasting and lengthwise cover more area. I got 35cm from the southern branch of the IOM streamers in 2010 over a 2/3 day period as did much of Kildare, Dublin, Carlow and Wicklow.

Tonight's easterly may push a few tiny flurries onto the coast outside of the IOM business, but they'll be so light it'll probably be snizzle. And looking at the radar, it's not great.

Rougies

John.Icy wrote: »

North Easterlies anyday for the East. Easterlies are usually too dry for most. Streamers only kick off at certain points, they wont just form out of nothing. The IOM is our streamer machine. In an easterly, it's the north and south tips that get streamers going, like tonight, and in a north easterly its on the west and east tips of the IOM they fire up from, like 2010. With a NE there's a longer sea fetch, so streamers are more intense and longer lasting and lengthwise cover more area. I got 35cm from the southern branch of the IOM streamers in 2010 over a 2/3 day period as did much of Kildare, Dublin, Carlow and Wicklow.

Tonight's easterly may push a few tiny flurries onto the coast outside of the IOM business, but they'll be so light it'll probably be snizzle. And looking at the radar, it's not great.

Any idea why the IOM fires them up on either side?

finnharpsboy

no snow here so so sad

coffee to go

Rougies wrote: »

Here, I rotated it for you. Nice panorama!
http://imgur.com/Vi2m9Nu

Doh! Stupid mobile upload. Thanks for the fix.

delw

Very light sleet coming down here at the minute,probably the best we'll get all night :rolleyes:

Mr Cumulonimbus

Rougies wrote: »

Any idea why the IOM fires them up on either side?

You can see that now on the 1930 radar. Seems to be another streamer forming at the southern tip of the IoM.

EDIT: better again on the 1945 radar.

dacogawa

M2 buoy down to -0.1 dew point, Howth at dew point 0.4°C (temp2.3°C)

Just hope for something in from the Irish sea now!

If anyone in Dublin gets a chance go up to 3 rock for your snow withdrawal, it's a winter wonderland, knee deep in places, pics later, have to run...

snowstorm445

Rebelbrowser wrote: »

Im getting more worried the nearer we get. Thought it would be generally colder by now... I'll stick to my guns though and keep calling it a snow event.

Why are you losing faith? It's still very much on the cards at the moment.

maquiladora

Trotter wrote: »

What do I need to be watching for here in Waterford now?
I'm keeping an eye on the dew points and temp along with the rain today radar.

Am I right in saying our best shot here on the Waterford coast is 1am Monday morning to 7am Monday morning if the DP is below 0?

DP below 0, uppers of at least -5. Being close to the coast though will make it a bit more marginal. There is still uncertainty about just how far east precip will get, it could be very light if it does get to Waterford. Should be able to get some idea from reports earlier in the night along the Cork coast how likely rain/snow might be.

Don't expect too much!

Rougies

Mr Cumulonimbus wrote: »

You can see that now on the 1930 radar. Seems to be another streamer forming at the southern tip of the IoM.

Yeah I noticed that. I noticed it in 2010 too, but I didn't think that the IOM was actually causing it. I thought the streamers would have developed anyway, but the IOM was just getting in the way and annoying us with the shadow.

So the IOM is both a hero and a villain when it comes to streamers it seems. Interesting.

whitebriar

Its not the IOM that fires off showers,its just a reference point.
Its fetch,ie the length of sea track the cold air passes over,the longer the better and obviously the bigger the difference between the 850 temps and the sea temp the better.
Yes in my experience easterlies are dryer than northeasterlies due to shorter fetch than say a diagonal Ne down the Irish sea.
They're usually not bad for Dublin but just not as good.

Rougies

whitebriar wrote: »

Its not the IOM that fires off showers,its just a reference point.

John.Icy wrote: »

Streamers only kick off at certain points, they wont just form out of nothing. The IOM is our streamer machine. In an easterly, it's the north and south tips that get streamers going, like tonight, and in a north easterly its on the west and east tips of the IOM they fire up from, like 2010.

So which is it
A bit of both I would say. Streamers can and do form out of nothing in the middle of a lake. Look at the Great Lakes snow for instance.
I would say the IOM can help kick them off though. It certainly looks that way anyway. Both now and in 2010

snowstorm445

maquiladora wrote: »

DP below 0, uppers of at least -5. Being close to the coast though will make it a bit more marginal. There is still uncertainty about just how far east precip will get, it could be very light if it does get to Waterford. Should be able to get some idea from reports earlier in the night along the Cork coast how likely rain/snow might be.

Don't expect too much!

I'll keep you posted. Although don't think you'll be getting the same weather, it may well be a whiteout in Waterford and a washout in Cork, or vice versa, or both the same!