Prolonged cold spell on the way

Elmo5

Heard Vincent O'Shea from Met Eireann on radio this afternoon. Saying risk of snow for many places over the weekend. Only precip type mentioned was snow

Su Campu

Surface winds flow neither along nor between isobars. Over land they wind flows at about a 30° angle to the isobars, towards the low pressure centre. Over the sea, where surface friction is reduced, this angle is less, more like 15-20°. So when you see isobars on a chart, first see if they're over water or land, then estimate the surface wind by applying the angle above.

BEASTERLY

Deleted User wrote: »

The charts you posted are for today...not sunday...
Also have a look at the sea area forecast..

http://www.met.ie/forecasts/sea-area.asp

Those charts I posted for today was just to illustrate the point about how winds travel at slight angles from isobar to isobar from higher to lower pressure and not parrallel to them.

Look at the ECM, sunday 0100 hrs is the first chart to show any sort of Easterly hint to the wind.

I'm not saying the ECM is correct but it is something to note before we start talk of streamers for the east.

BEASTERLY

Su Campu wrote: »

Surface winds flow neither along nor between isobars. Over land they wind flows at about a 30° angle to the isobars, towards the low pressure centre. Over the sea, where surface friction is reduced, this angle is less, more like 15-20°. So when you see isobars on a chart, first see if they're over water or land, then estimate the surface wind by applying the angle above.

Thanks you Su, that is what i was trying to say about slight angles, Northerly winds it is so. No Snow for us in the east till sunday so. lol

Apology please BB? Just joking:P

homolumo

mickger844posts wrote: »

Hope so too Derek but i remember one of the experts in here last Winter gave the reasons why we don't get much snow down here. Its all about location i guess. Maybe this Winter could be a good one

we did have one nice day of snow

maquiladora

BEASTERLY wrote: »

No Snow for us in the east till sunday so. lol

Don't forget that these are only models, and the models are changing slightly on every run anyway.

nacho libre

Elmo5 wrote: »

Heard Vincent O'Shea from Met Eireann on radio this afternoon. Saying risk of snow for many places over the weekend. Only precip type mentioned was snow

perhaps he could have a word with Gerry:pac:

For the avoidance of doubt,Beasterly you are wrong regarding wind direction on saturdayI'll post the UKMO wind page which is usually a blend of their model and the ecm and for day time saturday,the wind direction is north east.. (updated 10 mins ago) play saturday...
Even at 20 degree's off the angle of the isobars

http://www.metoffice.gov.uk/weather/uk/uk_forecast_wind.html

mickger844posts

homolumo wrote: »

we did have one nice day of snow

Yeah one day in one of the coldest Winters on record. Not a very good return compared to vast majority of the country.

maquiladora

maquiladora wrote: »

Don't forget that these are only models, and the models are changing slightly on every run anyway.

Indeed and thats what we always say on here too.
The ukmo may change their outlook for saturday but as of now,they are charting a swing of winds back to the northeast as the UK low moves south and thats what you'd expect to happen.

I can't believe I'm having this conversation,it's basic stuff

Now no more of this no snow in wexford stuff please :D (or waterford )

BEASTERLY

Deleted User wrote: »

For the avoidance of doubt,Beasterly you are wrong regarding wind direction on saturdayI'll post the UKMO wind page which is usually a blend of their model and the ecm and for day time saturday,the wind direction is north east.. (updated 10 mins ago) play saturday...
Even at 20 degree's off the angle of the isobars

http://www.metoffice.gov.uk/weather/uk/uk_forecast_wind.html

Ok fair enough, if that was right were in business. Let's just hope it stays that way. Suppose we won't know until friday night, lol.

Ah I'm only trying to reassure you Beasterly

All friends now? what brand of ski do you have ?

nacho libre

danielpaul wrote: »

will we see snow in killarney like last year it was amazing

what a fantastic scene that is! i bet that shot would do well in a weather photo competition.

Su Campu

Just to clarify the wind thing - surface winds flow at an inward angle to the isobars, but this angle reduces with increasing elevation through the boundary leayer until the flow is pretty much parallel to the isolines (say the 850hPa height lines), ie. geostrophic wind.

For figuring out sea tracks of showers etc, isobars are not the most reliable, as it is is the upper winds (say 850-700hPa) that will be steering the showers. So take a look at the 850 and 700 geopotential charts and take roughly the average of the two to see "what way the wind blows" - literally!

carlmwan

WolfeIRE wrote: »

check this carl
http://www.earthtools.org/

just find your location and it will give you an approx height.

By the way, any chance people could post their height asl and their approx location if possible.

drove me mad last year reading posts 'Snow shower here' etc with no location.

thanks thats a great site it has contour lines and everything im at 46m asl but there is a area beside me at 100 asl

WolfeIRE

nacho libre wrote: »

what a fantastic scene that is! i bet that shot would do well in a weather photo competition.

that's included in a weather gallery in posted today. thanks to some of the folks here who contributed. http://www.irishweatheronline.com/2010/11/gallery-big-freeze-2009-10.html

Regarding precipitation for the next 48 hrs or so this HIRLAM is a good guide
http://www.dmi.dk/dmi/index/danmark/vejrkort.htm
click on nedbor.
also has a temperature run.

Also, here is a great wind guide for ireland. don't forget to select your location in Ireland
http://www.windguru.cz/int/index.php?sc=47736

Deep Easterly

Deleted User wrote: »

The ECM and the UKMO have much more human input and are much more in tune with what happens here.

Are you sure about that BB? There is human input into the actual interpretations alright in official forecasts but not in the actual outputs themselves.


A fairly good way to predict the path of showers is to look at what direction the 500h streams are moving:



of course there would be more to it than but will give a fairly good idea as to the direction any showers would be moving in.

ninebeanrows

I am a measly 21m above sea-level!

WolfeIRE

Weathercheck wrote: »

I am a measly 21m above sea-level!

only joking WC:pac:

Deep Easterly

Weathercheck wrote: »

I am a measly 21m above sea-level!

39 m asl here

Rougies

65m here. Woohoo I'm above Su Campu's "low-level" bracket

Better order the snow chains....

maquiladora

Deep Easterly wrote: »

39 m asl here

36 :mad: :rolleyes:

rhonin

50M here.
The home place in Belmullet is 162M

Elmo5

69m I think

nacho libre

Deep Easterly wrote: »

39 m asl here

75 m asl here.

Rougies

Elmo5 wrote: »

69m I think

You think!?

http://www.earthtools.org/

Get with the times!

Lumi

maquiladora wrote: »

36 :mad: :rolleyes:

A pathetic 14m asl

nacho libre

WolfeIRE wrote: »

that's included in a weather gallery in posted today. thanks to some of the folks here who contributed. http://www.irishweatheronline.com/2010/11/gallery-big-freeze-2009-10.html

Good stuff Wolfe'. Hopefully you'll have a few more wintry images to add to it in the coming days.

maquiladora

12Z NAE has snow showers approaching the northwest coast tomorrow evening

help cant find Su's low level bracket guide LOL
Im 48m (if I done it right ) above sea level