Cold Spell Media Forecasts and Model Output (General Chat)

wildefalcon

dak wrote: »

Wikipedia!


Mesoscale meteorology is the study of weather systems smaller than synoptic scale systems but larger than microscale and storm-scale cumulus systems. Horizontal dimensions generally range from around 5 kilometers to several hundred kilometers. Examples of mesoscale weather systems are sea breezes, squall lines, and mesoscale convective complexes.
Vertical velocity often equals or exceeds horizontal velocities in mesoscale meteorological systems due to nonhydrostatic processes such as buoyant acceleration of a rising thermal or acceleration through a narrow mountain pass.

Thanks! So, that means it's big, yes? Serious winter event.

dak

I think the Mesoscale Model uses archived upper level atmospheric data to extrapolate wind speeds to ground level for any given height!

wildefalcon

dak wrote: »

I think the Mesoscale Model uses archived upper level atmospheric data to extrapolate wind speeds to ground level for any given height!

and an excerpt from MT Craniums earlier post:

"it makes sense to be on the alert for greater development of meso-scale features; the models have a deceptive look of sudden calm and weak wind fields that may prove misleading to some extent. "

Does this mean the cold "up there" will come down here, because there isn't much happening down here.

Wasn't there a movie about that? Lots of Snow, and people from the US fleeing across the border to Mexico?

Thank goodness this thread allows "general chat", as my mind wanders in mad directions.

Villain

So now we have seen the dreaded downgrades, 18z ain't call the pub for no reason.

maquiladora

Villain wrote: »

So now we have seen the dreaded downgrades, 18z ain't call the pub for no reason.

A downgrade of some sort was inevitable after that. There couldn't really have been much more of an upgrade.

thetonynator

Villain wrote: »

So now we have seen the dreaded downgrades, 18z ain't call the pub for no reason.

what happened in the 6z or is it out yet?

JeanLucPicard

Im confused...

I have to travel from Wexford to Dublin on Friday evening....will this be possible?

Is the Wexford town area likely to get the predicted heavy accumulations of snow forecasted?


I cant read maps or charts so hopefully someone in the know can help me out.

Thanks everone

JeanLucPicard

Wasn't there a movie about that? Lots of Snow, and people from the US fleeing across the border to Mexico?

[/QUOTE]

That movie was The Day After Tomorrow I think!!

Villain

I wouldn't try and forecast anything beyond 12 hours at this stage charts are changing hugely on every run. Its wait and see I'm afraid

nacho libre

Villain wrote: »

I wouldn't try and forecast anything beyond 12 hours at this stage charts are changing hugely on every run. Its wait and see I'm afraid

exactly
the bottom line is don't take any run too seriously. you could end up with an ulcer otherwise!

cherryghost

I'll say again what I said yesterday. The charts won't ever give 100% accuracy. For a more stable reading, wait until tonight, things will be more set in stone.

Although the weekends features seems like a downgrade, don't let your guard down. It's still some serious stuff that's predicted, especially over Friday night/Saturday.

davehey79

cherryghost wrote: »

I'll say again what I said yesterday. The charts won't ever give 100% accuracy. For a more stable reading, wait until tonight, things will be more set in stone.

Although the weekends features seems like a downgrade, don't let your guard down. It's still some serious stuff that's predicted, especially over Friday night/Saturday.

do you still think Longford will get some of the snow this time round?

cherryghost

davehey79 wrote: »

do you still think Longford will get some of the snow this time round?

A definite yes. If not tonight, then tomorrow and tomorrow night

davehey79

cherryghost wrote: »

A definite yes. If not tonight, then tomorrow and tomorrow night

best news i heard all day thanks cherryghost

th3 s1aught3r

North Wales has a servere snow warning. Do you think that would make its way to our east coast or is it travelling straight down?

snaps

th3 s1aught3r wrote: »

North Wales has a servere snow warning. Do you think that would make its way to our east coast or is it travelling straight down?

No because its only NW facing coasts that will get the percip.

maquiladora

Forgot about this thread!

Warnings


Weather Warning

Issued at 16 December 2010 - 11:19
Update on Severe Weather
Very cold wintry weather will start today and will continue into next week with ice by day and by night.
Snow showers developing this afternoon and continuing tonight and Friday morning. These falling mainly over Ulster and Connacht initially, but some showers will reach parts of west Munster, the Midlands and north Leinster later.
Total accumulations up to Friday lunchtime
5 to 10 cm over Ulster, and Connacht, worst on high ground, with possibly some drifting, but totals of 2-5 cm elsewhere.

A second more significant snow event is expected to occur during Friday afternoon, Friday night and for a time on Saturday. A band of heavy snow is expected to spread across the country from the west and northwest.
Further totals of 10-15cm possible, with all areas at risk.


National Forecast



16 December 2010 11:37

Today

Cold and windy this afternoon with temperatures continuing to fall. Some dry bright spells, but showers also. These will turn wintry in the North and West, with snow in places.
Tonight

Very cold and icy tonight with occasional snow showers. These most frequent over the north and west, with some drifting possible on high ground. The snow showers will be scattered elsewhere. Lowest temperatures zero to -3 degrees and feeling colder in the brisk northerly wind.


Tomorrow

Very cold and wintry again tomorrow with further snow showers, mainly over Ulster, Connacht and west Munster, but some dry bright spells too. Later in the day, a band of more persistent snow will reach the West before spreading countrywide. It will be bitterly cold, top temperatures zero to +3 degrees at best, but feeling colder in the fresh northwesterly wind.

http://www.met.ie/forecasts/

cherryghost

These charts are going to change in a few hours for sure. Not only is there a low forming and heading SE towards us as we speak, theres a new low forming in Eastern England.

This may result in Fridays snow front moving across the country slower than expected, and maybe hanging further west than this mornings charts are indicating

Not

maquiladora wrote: »

A second more significant snow event is expected to occur ...


http://www.met.ie/forecasts/

Not like them to use such terminology.

Looks like their official meterological forecasting speak is starting to be influenced, I wonder where from ?:D

ninebeanrows

cherryghost wrote: »

These charts are going to change in a few hours for sure. Not only is there a low forming and heading SE towards us as we speak, theres a new low forming in Eastern England.

This may result in Fridays snow front moving across the country slower than expected, and maybe hanging further west than this mornings charts are indicating

Where are these developments you talk of?

snaps

cherryghost wrote: »

These charts are going to change in a few hours for sure. Not only is there a low forming and heading SE towards us as we speak, theres a new low forming in Eastern England.

This may result in Fridays snow front moving across the country slower than expected, and maybe hanging further west than this mornings charts are indicating

Can you explain more please?

nacho libre

cherryghost wrote: »

These charts are going to change in a few hours for sure. Not only is there a low forming and heading SE towards us as we speak, theres a new low forming in Eastern England.

This may result in Fridays snow front moving across the country slower than expected, and maybe hanging further west than this mornings charts are indicating

this is what i've been saying- some places could end up with locally heavy falls of snow due to shallow lows developing in a 6- 12 hour period. the models will generally struggle this weekend due to how complex a setup it is.

th3 s1aught3r

nacho libre wrote: »

this is what i've been saying- some places could end up with locally heavy falls of snow due to shallow lows developing in a 6- 12 hour period. the models will generally struggle this weekend due to how complex a setup it is.

Are these fronts harder to predict than say normal atlantic fronts that we are more used to ? So we could see changes to forecasts right along the timelines

cherryghost

Yeah, they're popping up anywhere. FAX have some interesting chart readings for Saturday regarding the lows forming

Iancar29

cherryghost

Friday evening still looking good



Might change in a few hours, updated models on the way

Mayo Exile

GFS 12Z starting to appear now

WolfeIRE

http://www.dmi.dk/dmi/index/danmark/vejrkort.htm

click on nedbor

that system will deliver significant snow. would expect it to be even more widespread than this indicates

Wibbler

WolfeIRE wrote: »

http://www.dmi.dk/dmi/index/danmark/vejrkort.htm

that system will deliver significant snow. would expect it to be even more widespread than this indicates

Why? Does it normally underplay it?

cherryghost

Wibbler wrote: »

Why? Does it normally underplay it?

Yeah, it usually underplays by about 50-100 miles. I guess its accurate, but conservative, if you put it that way