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7/1/08 to 13/1/08 Cold spell?
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Rofl.
You do realise that met check dont "come on board".
Their forecast is the current GFS run and they change it for every GFS run.
So if Fantasy island GFS says theres going to be Tornado's in Portlaoise on the 27th of this month,you'll have that on met check.
So really posting met check forecasts as a fact to support a theory is nonsense.
Have a look at them now and they'll reflect this mornings run... and rain.
All your other links reflect GFS's new position too including a 528 line way north of Ireland.
Besides you's need a thickness of 520 or lower at a min for atlantic snow as the layer of air closer to the surface is too modified by the warm atlantic surface to support snow.
Looking at GFS beyond 96hrs hrs(as you were doing 2 days ago) and getting excited about snow in marginal enough conditions is folly.
Of course it may change out of no where but wheres the accuracy in FI GFS then...I'll tell you where ,touching the cloth of the rear end of my pants to be honest
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Anything beyond 48hrs is FI tbh in GFS at the moment.The first time I posted links were in the 60hrs range - hardly FI :rolleyes:
Well you didn't seem to know that metchecks forecasts are from GFS and change with every run when you said they had come "on board" as you put it.Anything FI posted was at the time 216hrs out and was linked to just to show how an evolution can take place. Read back through my posts a bit more carefully in future please!
They even have that as a qualifier on the bottom of each forecast page if you care to look...
You also seemed to think that the 528 dam line coming in from the atlantic was significant,it's not.
2 things had to be pointed out to you there in the "theory" you were putting foward.
We can of course agree to disagree on how silly it is to rely on one run of the GFS to confidently predict weather.
As for evolution,thats nonsense.You can't post a run and say this is going to evolve into x,y or z.
It either will or it won't.
Minus a time machine of course 0 -
Looks very good for Monday Midnight/Tuesday 6am according to the current charts. Areas north of the N6 should get a pasting according to todays 12z runs:
Also, I was being quite specific about where the risk laid, kinda like what is happening tonight here: http://www.boards.ie/vbulletin/showthread.php?t=2055211895
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Deleted User wrote: »As for evolution,thats nonsense.You can't post a run and say this is going to evolve into x,y or z.
It either will or it won't.
Minus a time machine of course
But, I showed the two ECM runs from FI in two posts one right after the other - posts 21 and 22. These were showing how the ECM expected it to evolve, not me!!! Though the chart looked sweet!
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no you posted them, he never mentioned metcheck untill you posted them (lol and you are telling me to read againLook again - I was posting those Metcheck's in response to Damomanye post #25. Metcheck's were for Tuesday Night/Wednesday Morning.) and you specefically refered to metcheck "coming on board" as a direct support for your theory which is why I thought you needed clarification on what those metcheck forecasts actually are.In order to be precise what you should have said was GFS has came on board but really and truly that would be saying the same thing twice and anyhow,I wouldn't be relying on one run in a marginal set up
Yeah but firstly my reply was in direct response to your about tuesday post and not tonight.I wasn't commenting on tonight at all untill now really.Knock airport is circa 800ft asl.Quite a number of roads in the area also traverse high ground or are immediately adjacent to it(which helps a lot in marginal situations),thats where most of the snow is.I wouldnt call it a pasting though.Agreed - http://www.wetterzentrale.de/pics/Rtavn123.png - even shows that above 528 can deliver snow to Mayo tonight.
528 on it's own could not deliver that snow,it needs several other factors to come into play including a cold surface feed not sourced in the mid atlantic.
Some of those factors have indeed came into play tonight up north eg a SE or east wind off a cold surface source turned what started as rain to wet snow.It took a while to do that as it was marginal and had it's work cut out for it to do that.Parts of inland ulster that remained cold all day after a frosty start.
Castlederg for instance had a max of 2c today helpfully providing that surface cold feed.
What happens later in this though is in the lap of the mixing thats going to occurr as a result of the stronger winds.
(That chart above incidently is a projection for midnight not now)0 -
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Uhm-why did you say it was "coming on board" if you knew it was just a mirror image of the GFS?Why would I post Metcheck T+76 and T+80 Pages to back up GFS T+54 and T+60 Charts :?
That chart shows monday.The http://www.wetterzentrale.de/pics/Rtavn123.png chart shows(ed) the majority of NW Ireland to be outside of the sub 528 area, follow the isobar lines back to see where the sub 528 air is coming from, pretty safe to conclude that Sligo and Mayo were under air above 528 dam and still got snow this evening.
It's not monday yet.
Also,thickness demarcations are often drawn in crazy shapes,you cant follow them in the same way as you can an isobar.
LoL for example,you'd be forgiven for thinking that the light blue line there was drink driving.
Someone go out and arrest it 0 -
The GFS Output yet another chart since I posted last, hence I put in (ed) after shows!
Here is tonights chart: http://85.214.49.20/wz/pics/Rtavn063.png0 -
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Ha no he is not when you are talking about a Westerly off the atlantic.Guys, guys............the 528 line is VERY important for snowfall. It is air thickness and generally needs to be below that level to bring snow to low levels. The 528 dam line generally denotes the -5 850 line. Danno is right on this occasion.:D
546 dam is a good enough thickness level for instance to bring snow in the U.S as the air flow is traveling almost exclusively down a cold continental land mass!
546 would probably give us hot hail like in the flash Gordon film here 0 -
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Zero or below dewpoints are pretty much essential for sea level snow danno alright(though you can get it at almost 1c dp too if you have a cold feed down off an adjacent mountain-in which case it either won't be lasting long or your dp will drop to 0 or below thanks to the mountain feed) but they won't guarantee it on their own as witnessed by places in the East that had rain and sleet with 0 and below dewpoints on Friday morning.Some places would have had snow that turned to sleet despite a zero dewpoint or below.
Other factors came into play like higher upper air temps and a sea air feed.
Claremorris is another example tonight reporting over an hour ago light rain with a 0c air temp and a 0c dew point.
I guess my point throughout is you do need a lot of factors together to get your snow and often you need luck not to be missing one or more of them 0 -
Too true - hence my extensive analysis of that model run back on page 2! All them factors were together on those charts. Unfortunately GFS has back-tracked from the slightly now - but who knows - maybe tonights 00z, tomorrow's 06z, 12z and 18z might bring it back for us. The low pressure tonight is not going as planned (forecasted) and might tilt the balance back in our favour when tonights data gets inputted in to those runs tomorrow.
Fascinating stuff! 0 -
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