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

Gremlin

Confab wrote: »

Definitely the last of the snow for Dublin.

Can you explain meteorogically, how you arrive at that conclusion? I'm not trying to be smart, just interested.

pistolpetes11

Confab wrote: »

Definitely the last of the snow for Dublin.

Care to back that up ?

lucernarian

The latest forecast from the meteorologists in Dublin Airport (the TAF forecast) suggests sleety rain and graupel showers until about 5 or so this evening, then from about 6pm onwards until 12 middday tomorrow there will be falls of snow. The models are also upping the precipitation totals for early tomorrow morning and tomorrow afternoon too, for the east coast. I expect that this evening there will be continued penetration of showers into the southern midlands. How much exactly is hard for me to say!

nacho libre

pistolpetes11 wrote: »

Where did you get that from ?

Which sites show the 06z run first ?

they are the thoughts of netweather's chief forecaster.

compsys

To_be_confirmed wrote: »

The latest forecast from the meteorologists in Dublin Airport (the TAF forecast) suggests sleety rain and graupel showers until about 5 or so this evening, then from about 6pm onwards until 12 middday tomorrow there will be falls of snow. The models are also upping the precipitation totals for early tomorrow morning and tomorrow afternoon too, for the east coast. I expect that this evening there will be continued penetration of showers into the southern midlands. How much exactly is hard for me to say!

Oh I really hope so. It always seems like the best snow is 12 hours away. Would really love some daylight snow though.

Cionád

3hr chart looks decent for Dublin if the temperatures drop

Calibos

Gremlin wrote: »

Can you explain meteorogically, how you arrive at that conclusion? I'm not trying to be smart, just interested.

I don't recal if Confab is one of the boards 'Experts'. Think he might be just one of the laymen like ourselves who should really have posted that in the other thread.

As a result, I don't think he can explain it meteorogically. It can certainly be explained Psychologically though. ie. Pessimism, glass half empty. He's just on a downer from the sleet and rain and thaw and losing his weekend snow.

I'd be the same only for the fact that conditions for snow are to return from 12pm onwards to the same if not better conditions for snow then they were for the weekend stuff. Had those conditions not delivered for us on the seafront locations of the east on the weekend, I would remain pessimistic. ie I'd believe it when I see it. However seeing as they did deliver for us at the weekend I see no reason not to be optimistic that they will deliver again this evening.

Sure I would have preffered for what we had on the ground from the weekend to remain to provide a base for the fresh stuff coming today or tomorrow. As it stands now with the thaw and slush we will basically be starting from scratch again. But I am confident of waking up tomorrow morning to at least the same snow levels and beautiful winter wonderland scenes I woke up to on Sunday Morning.

All that said, and it was a lot said tbh I would prefer if this thread was kept to the boardsie experts discussing events and forecasts. I know their discussions between themselves can get a bit impenetrable to the layman like ourselves but maybe an expert every 10 posts could summerise in laymans terms the previous few technical posts. This thread is already full of posts and pictures that should have been posted in the general thread and not the forecasting technical thread.

Timistry

Cionád wrote: »

3hr chart looks decent for Dublin if the temperatures drop

Kerry has the front and back door open and the snow just does not want to come in to say hi!

pistolpetes11

Timistry wrote: »

Kerry has the front and back door open and the snow just does not want to come in to say hi!

Thats open to so many different interpretations

pistolpetes11

nacho libre wrote: »

they are the thoughts of netweather's chief forecaster.

An excellent outlook if it proves to be the case .

Timistry

pistolpetes11 wrote: »

Thats open to so many different interpretations

so it is! Lets just stick to the weather related ones for now;) Seriously though, kerry, limerick and clare are having no luck!

pistolpetes11

M2 buoy down to -0.5

Su Campu

Jake1 wrote: »

Su, how well do you think our neck of woods will do from the snow later? Are we far enough inland for decent snow today , ?

Thanks.

I'd be very confident that we'll see proper snow again this evening with the colder air setting in again. More streamers off the sea, as we've seen for days. I'd expect the flakes to be fairly large, and the depths to build quicker. Also with winds dying down, frost will be harsh, leaving treacherous driving conditions on today's slushy roads.

nacho libre

pistolpetes11 wrote: »

An excellent outlook if it proves to be the case .

yes. let's hope so. on the model threads over on netweather his opinion is always valued. he did say sometime back that December would be a cold month overall. Our own M.T.Cranium has hinted these next two-three days are likely the peak of the cold, but his winter outlook also suggests December will be colder than average. So all in all there are grounds of optimism we'll see a bit more of the white stuff from time to time in December.

Su Campu

Su Campu wrote: »

I'd be very confident that we'll see proper snow again this evening with the colder air setting in again. More streamers off the sea, as we've seen for days. I'd expect the flakes to be fairly large, and the depths to build quicker. Also with winds dying down, frost will be harsh, leaving treacherous driving conditions on today's slushy roads.

Aw Thanks a million, I was hoping you'd say something like that!! :D:D

nacho libre

Su Campu wrote: »

I'd be very confident that we'll see proper snow again this evening with the colder air setting in again. More streamers off the sea, as we've seen for days. I'd expect the flakes to be fairly large, and the depths to build quicker. Also with winds dying down, frost will be harsh, leaving treacherous driving conditions on today's slushy roads.

Su Campu, since you're in the mood for good news, is there any chance you could rustle up a polar low for your cousins in the west and northwest for this weekend?

Tom Cruises Left Nut

M2 down to 0.5

Pangea

My question is getting lost in the other thread, il post it here.

Just wondering, seeing as the easterly winds are really driving down tempertures, they said with the northern winds at the weekend tempetures will not be as severe, Is this always the case?? Is air from east always colder than the norths?
Northerly winds will give more snow potential for me Im pretty sure.

pistolpetes11

Su ,

All them showers bubbling up in the north Sea, do you think that they could hit land over here ?

Su Campu

pistolpetes11 wrote: »

Su ,

All them showers bubbling up in the north Sea, do you think that they could hit land over here ?

Those showers are forming in -12-13°C T850s, which is the coldest we've seen so far. While we won't get them that low over the Irish Sea, they are forecast to get below -10°C, which will cause more explosive convection off the east coast. 500hPa levels will be slightly warmer than previously, but there is increasing deep layer shear, so we could see more organised bands of convection forming evernight, with some thundersnow and graupel again. Their more organised nature may keep them going further inland, maybe 2 or 3 counties, instead of the 1 over the last couple of days.

Gremlin

pistolpetes11 wrote: »

Su ,

All them showers bubbling up in the north Sea, do you think that they could hit land over here ?

I will first say that I'm not an net expert but If i understand it correctly we are in essentially the same airmass as those north sea showers. Because of the temperature differential between the land and sea (the sea being relatively warm) the showers bubble up there but lose their intensity and fade away as they pass over the UK landmass. Once the air hits the irish sea it warms again creating the convective activity you can see on the satpic animations. However because the irish sea is nowhere near as big as the north sea the showers are not as intense since they have had less time to convect before they hit land again.

If I got that wrong maybe the met experts will correct.

PS any of you met experts prepared to lay your reps on the line and give a 24 hr snowcast?

nacho libre

Pangea wrote: »

My question is getting lost in the other thread, il post it here.

Just wondering, seeing as the easterly winds are really driving down tempertures, they said with the northern winds at the weekend tempetures will not be as severe, Is this always the case?? Is air from east always colder than the norths?
Northerly winds will give more snow potential for me Im pretty sure.

less cold, yes, but, for you, it means a much greater chance of wintry showers than anyone else in the country, if it's a proper northerly

TheMilkyPirate

What are lee clouds su? And what effect do they have?

dave1982

Raining here now :mad:

Mayo Exile

pistolpetes11 wrote: »

M2 buoy down to -0.5

Down to -1.3 at 1300.

Calibos

Have I got this right.

While the colder air mass coming from the east is starting to slow down and reverse the thaw and DP's are now back in negative figures, that until the deep cold really digs in across the Irish sea, we will only see the mild convection and scattered shower streams we are seeing now at 2pm. However, later tonight when the deep cold really starts making progress over the Irish sea, its only then that the real explosive convection gets going and we then start seeing really beefy streamers delivering the kind of intensity and shower durations we saw on Saturday and Sunday night.

Would I be also right in thinking that the current wind direction of almost due east is actually going to make things even better than the weekend because of the longer sea track for the streamers. ie. at the weekend we were getting streamers forming off the Dundalk coast and tracking South West towards Dublin and Wicklow, whereas today the sea track will be all the way from the Cumbrian/Blackpool coast in the UK towards Dublin/Bray/Wicklow. ie twice as long a sea track as the streamers on Sat/Sun??

Mayo Exile

Time is 1209GMT. Image in visible spectrum.

Credit to NERC Satellite Receiving Station, Dundee University, Scotland.
Link: http://www.sat.dundee.ac.uk/

Rougies

Calibos wrote: »

Have I got this right.

While the colder air mass coming from the east is starting to slow down and reverse the thaw and DP's are now back in negative figures, that until the deep cold really digs in across the Irish sea, we will only see the mild convection and scattered shower streams we are seeing now at 2pm. However, later tonight when the deep cold really starts making progress over the Irish sea, its only then that the real explosive convection gets going and we then start seeing really beefy streamers delivering the kind of intensity and shower durations we saw on Saturday and Sunday night.

Would I be also right in thinking that the current wind direction of almost due east is actually going to make things even better than the weekend because of the longer sea track for the streamers. ie. at the weekend we were getting streamers forming off Strangford Lough off the NI coast and tracking South West towards Dublin and Wicklow, whereas today the sea track will be all the way from the Cumbrian/Blackpool coast in the UK towards Dublin/Bray/Wicklow. ie twice as long a sea track as the streamers on Sat/Sun??

Yup, good explaination of the situation. You might want to post that in the chat thread for some of the people despairing at their snow melting right now!

kakee

<snip>

cherryghost

We should see an intensity coming from the east starting from 5pm. Prolonged sleet strengthening through the night for some heavy snow showers.

Snow may not be as widespread as last night but given the intensity of forecast, snow should make it inland as far as Westmeath (Athlone hopefully :pac:)