Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Winter/Spring 2013 (Model Output Discussion)
Options
Comments
-
-
-
-
-
Still do not see anything exciting on the cards. Short/mid term potential indeed for the North and NW mostly.
After that? Mid Atlantic ridge will either collapse over us ala the latter stages of the ECM tonight, and GFS I think, or it might link up with the Russian high to form a Scandi block at first, maybe ridging west towards Iceland at time. (Based on GEFS charts, pinch of salt required.) Or will it go to greenland, who knows!
And an important note, tomorrow is the first day of February, in a week, it'll be the 7th. The extent of cold needed for a decent cold spell is increasing each day. The sun will melt any accumulations on paved surfaces unless there is severe cold over the country, which I don't see yet. I'd say at a guess that a 2 week decent cold spell at this time of year uppers of at least -12 or lower would be needed?? Snow will fall at higher 850's but think back to Feb 2009. I went from 4-6 inches of powder snow on pavements to 0 in the spaces of 3 hours when the sun made a few appearances in between showers. Not much melt on grass, but it was a horrible slushy mess in general.
If we are too see a severe cold spell, it'll be from the North mostly I say, there's just not enough cold pooling to our east in the case of an easterly, a north easterly would be better, but a direct northerly would get the coldest air to us quicker.
A chilly time ahead...cold at times...the cold that most of us want? Maybe for those in the north
Anyway here's to a clearer picture over the weekend of what the mid Atlantic ridge decided to do next week.
North/west is the place to be!0 -
Advertisement
-
-
-
And an important note, tomorrow is the first day of February, in a week, it'll be the 7th. The extent of cold needed for a decent cold spell is increasing each day. The sun will melt any accumulations on paved surfaces unless there is severe cold over the country, which I don't see yet. I'd say at a guess that a 2 week decent cold spell at this time of year uppers of at least -12 or lower would be needed?? Snow will fall at higher 850's but think back to Feb 2009. I went from 4-6 inches of powder snow on pavements to 0 in the spaces of 3 hours when the sun made a few appearances in between showers. Not much melt on grass, but it was a horrible slushy mess in general.
!
I think you're being a bit pessimistic with regard to the potential of a cold spell to deliver for snow lovers later in the winter. The effect of the sun on snow melt is a lot less than you would imagine, as the snow reflects most of the sun's radiation. What happened in 2009 was the result of the temps being too high. They were lowered during the heavy showers and then climbed back up above freezing after the showers thus melting the snow. Would have happened anyway, sunshine or not.
Why do you think we would need 2 weeks of cold? Yeah it's true that it seems that way, but that's because it tends to take a while to get the cold to our island. Once the air is cold enough for snow, it's cold enough for snow, simple as that. It can get cold very quickly sometimes in the right setup.
And -12 uppers? Why? -8 to -10 uppers would be fine most of the time. The laws of thermodynamics don't care if it's nearly St. Valentine's day :P
Although in saying that 2 weeks of cold and -12 uppers would be great
0 -
17th february 1991-gave 8 inches of snow in Arklow in a whiteout streamer off the Irish sea from the northeast,after a week of ice days at either side,as good a fall as most got in the final days of november 2010.
I think you're being a bit pessimistic with regard to the potential of a cold spell to deliver for snow lovers later in the winter. The effect of the sun on snow melt is a lot less than you would imagine, as the snow reflects most of the sun's radiation. What happened in 2009 was the result of the temps being too high. They were lowered during the heavy showers and then climbed back up above freezing after the showers thus melting the snow. Would have happened anyway, sunshine or not.
Why do you think we would need 2 weeks of cold? Yeah it's true that it seems that way, but that's because it tends to take a while to get the cold to our island. Once the air is cold enough for snow, it's cold enough for snow, simple as that. It can get cold very quickly sometimes in the right setup.
And -12 uppers? Why? -8 to -10 uppers would be fine most of the time. The laws of thermodynamics don't care if it's nearly St. Valentine's day :P
Although in saying that 2 weeks of cold and -12 uppers would be great
I do think,once you get past mid march though,mother nature is better to send warm weather to us,than cold as its much easier for warmth then than cold and nice too.0 -
I think you're being a bit pessimistic with regard to the potential of a cold spell to deliver for snow lovers later in the winter. The effect of the sun on snow melt is a lot less than you would imagine, as the snow reflects most of the sun's radiation. What happened in 2009 was the result of the temps being too high. They were lowered during the heavy showers and then climbed back up above freezing after the showers thus melting the snow. Would have happened anyway, sunshine or not.
Why do you think we would need 2 weeks of cold? Yeah it's true that it seems that way, but that's because it tends to take a while to get the cold to our island. Once the air is cold enough for snow, it's cold enough for snow, simple as that. It can get cold very quickly sometimes in the right setup.
And -12 uppers? Why? -8 to -10 uppers would be fine most of the time. The laws of thermodynamics don't care if it's nearly St. Valentine's day :P
Although in saying that 2 weeks of cold and -12 uppers would be great
Sure temps rose above zero at times in Feb 2009, but the increasing strength in the sun definitely played a role for my location anyway in terms of how rapid such a large fall melted. In the early days of Dec 2010 I had two days of above 0 temps with little to no snow melt in total cloud cover, drippings here and there, but not total wipeout.
And the -12 850's was in reference to MT's earlier thoughts that a big cold snap could last for quite some time, even into March IIRC correctly?? Maybe he's changed tune from that, but a few are pinning hopes on the appearance of a mid Atlantic ridge next week as a sign that a big cold spell is coming, when I just don't see the cold that would lead to that, unless we get a beastly Northerly blast and proper blocking, not a mid Atlantic ridge that could topple so easily.
And the colder the uppers the better anyway, as seen this month, -9 uppers didn't exactly riffle up anything notewhile did it? Although that Coldspell was quite stagnant to what we know the Irish sea can do.0 -
Advertisement
-
-
-
-
-
Sure temps rose above zero at times in Feb 2009, but the increasing strength in the sun definitely played a role for my location anyway in terms of how rapid such a large fall melted. In the early days of Dec 2010 I had two days of above 0 temps with little to no snow melt in total cloud cover, drippings here and there, but not total wipeout.
Yeah it was the same here in 2009 and 2010 regarding the sun's role in facilitating melting. I'm not saying it doesn't play a role, but I just thought you overestimated that role a bit The wind is also a factor, the stronger the above 0C wind the faster snow will melt, and far as I can recall it was windier in Feb 2010 than it was in early Dec 2010.And the colder the uppers the better anyway, as seen this month, -9 uppers didn't exactly riffle up anything notewhile did it? Although that Coldspell was quite stagnant to what we know the Irish sea can do.
Absolutely the colder uppers the better. The Irish Sea didn't get a chance to shine in the last cold(ish) spell as most of the precip was frontal related. We never really got a decent E/NE flow in place, it was always a bit all over the place hmmming and hawwwing, N/S/E/W, troughs and lows all over the place. It was a big mess. Wicklow mountains loved it though
0 -
True about 09/10, silly enough example.
That is true if there is plenty of snow about, but I'd still say if you had a snowfall say on a Monday for several hours, by that Wednesday/Thursday if you had nothing but sun and the odd flurry since the Monday, you'd want a very cold airmass to still have much on the ground if it was midway through February?
Yeah, but that would be the same for anywhere in the world. I'm, pretty sure there are places in Antartica with 24hrs sunshine with no snow melting going on. And in the eternal darkness of the Arctic, if the temp rises above 0c, snow's gonna melt!
Sun is a factor, but it's a pretty small factor in the grand scheme of things. (EDIT: of course the sun is THE factor regarding everything weather related and life as we know it)
But then again, we live in Ireland, snow marginality capital of the world. The heat from friction from a worm wriggling too excitedly 2 ft under the ground in Leitrim could scupper the chances of snow for the whole country 0 -
-
-
-
-
Advertisement
-
-
-
Looks absolutely bitter with the wind chill on Tuesday, strong NW'erlies piling in the showers in the north west. Probably mainly a high ground snow event but an interesting day nonetheless, should manage a few showers here hopefully. ECMWF still hinting at a more prolonged spell of below average temps as well
0 -
-
And an important note, tomorrow is the first day of February, in a week, it'll be the 7th. The extent of cold needed for a decent cold spell is increasing each day. The sun will melt any accumulations on paved surfaces unless there is severe cold over the country, which I don't see yet.
One comfort is that extent of cold often increases over the Northern Hemisphere in February which can sometimes peak as late as early March, this is because it can take a fair amount of time for such a vast area of the globe to cool down fully during the winter (lag effect).
At a local level, this graph shows the daily average temp at Birr for January & February (based on 71-00 30 year mean). Though this greatly masks day by day within month on month to year on year variation, it does show that cold spells in February tend to occur with an equal frequency - and possibly to a greater extent - than in January in Ireland. It also should be noted that RH & Td values tend to be lower in February also, which can actually make it feel even colder than January.
Data from the ECA&DNew Moon
0 -
One comfort is that extent of cold often increases over the Northern Hemisphere in February which can sometimes peak as late as early March, this is because it can take a fair amount of time for such a vast area of the globe to cool down fully during the winter (lag effect).
At a local level, this graph shows the daily average temp at Birr for January & February (based on 71-00 30 year mean). Though this greatly masks day by day within month on month to year on year variation, it does show that cold spells in February tend to occur with an equal frequency - and possibly to a greater extent - than in January in Ireland. It also should be noted that RH & Td values tend to be lower in February also, which can actually make it feel even colder than January.
Data from the ECA&D
Yes, all well said.
I get so bloody tired of people on this board saying every winter that once February comes it's somehow getting too warm too snow.
I remember many years when the coldest part of the winter was early March! And as well all know by now, it's statistically more likely to snow at Easter than it is at Christmas.
Just as the first two weeks of August are often the warmest, the first two weeks of February and beyond will often be the coldest for Ireland and Europe. A 'lag effect' as you have called it.
In fact, from a meteorological point of view, for some people, winter runs from 21st December to 21st March. As a result, we're very much still in winter.
If there's no sign of cold weather, even in FI, come 1st March, it might be time to put away the snow ploughs. But to be talking about the end of winter on 1st February is just stupid.0 -
-
-
-
Advertisement
-
This discussion has been closed.
Advertisement