Winter/Spring 2013 (Model Output Discussion)

Pangea

Weathering wrote: »

This snow has really come out of nowhere in donegal,I was expecting an isolated shower at most
What changed? I wonder will it continue for much longer

Too bad you wished for the mild weather , its on its way now for the end of the week, tut tut.

Courtesy Flush

Pangea wrote: »

Too bad you wished for the mild weather , its on its way now for the end of the week, tut tut.

Do the models suggest that the mild coming for this weekend will last long, well into next week ?

Caff Caff

Courtesy Flush wrote: »

Do the models suggest that the mild coming for this weekend will last long, well into next week ?

It will be a short peak of mild and a return to cold within a matter of days (2-3 perhaps) possibility of sharpening cold to a greater possibility of severe cold but still all quite uncertain at this time. That's what makes this an exciting time

Cantona's Collars

Rain & 10c for the weekend according to M E.

Weathering

Pangea wrote: »

Too bad you wished for the mild weather , its on its way now for the end of the week, tut tut.

I didn't wish for mild. I said this cold spell wasn't up to much for snow where I am ha. lets hope we all get a Northerly soon that half ars_d easterly can get

paddy ocon

would this be ust wind and rain for friday

Speak Now

paddy ocon wrote: »

would this be ust wind and rain for friday

Yes, a bit windy in the northwest but nothing special.

Rebelbrowser

Looking at the 12z NAE there is a weak band moving over the west tonight from NW to SE. Best prospects for snow look like Donegal/Sligo/Mayo direction but just looking at dew points and thickness, it could yet be snow for anywhere that actually gets this precipitation (not much would have to change).

On an imby basis, it passes through Cork at around 6am. Uppers are only -4 then but dew points are -3 and the 528 dam line is v close by so we could get lucky again.

snaps

Rebelbrowser wrote: »

Looking at the 12z NAE there is a weak band moving over the west tonight from NW to SE. Best prospects for snow look like Donegal/Sligo/Mayo direction but just looking at dew points and thickness, it could yet be snow for anywhere that actually gets this precipitation (not much would have to change).

On an imby basis, it passes through Cork at around 6am. Uppers are only -4 then but dew points are -3 and the 528 dam line is v close by so we could get lucky again.

looking on sat24 is that the band out to the west or is that the boundry between the cold air and mild air due to hit us on Thursday?

Villain

Some heavy rain totals showing for Friday and Saturday, if current charts hold I'd expect some flooding

Rebelbrowser

snaps wrote: »

looking on sat24 is that the band out to the west or is that the boundry between the cold air and mild air due to hit us on Thursday?

Not sure tbh. I'm finding it v hard to reconcile certain charts to others during this spell.... On balance though I don't think this is Thursday's front.

maquiladora

12Z GFS winds up that low off the northwest on Friday to to 959mb.



An area of very tightly packed isobars.



Sustained hurricane force winds at sea.



Worth keeping an eye on, if that track shifted south the west/northwest would be in for some severe winds.

Then the next day the GFS produces another Atlantic low (not near Ireland) with pressure down to 925mb, which in itself if interesting because only a handful of north Atlantic storms on record have been below 930mb.

Larbre34

This may be a silly question but does ultra low pressure always guarantee strong winds or is it the overall rate of change of pressure from highest to lowest within a system that gets the air moving at speed?

maquiladora

Larbre34 wrote: »

This may be a silly question but does ultra low pressure always guarantee strong winds or is it the overall rate of change of pressure from highest to lowest within a system that gets the air moving at speed?

The steeper the pressure gradient, the stronger the wind.

Mr Cumulonimbus

maquiladora wrote: »

12Z GFS winds up that low off the northwest on Friday to to 959mb.

Then the next day the GFS produces another Atlantic low (not near Ireland) with pressure down to 925mb, which in itself if interesting because only a handful of north Atlantic storms on record have been below 930mb.

Nasty. Interestingly the 20th anniversary of the "Braer Storm" has just passed. Esimated pressure of 914mb at it's lowest point.

maquiladora

Mr Cumulonimbus wrote: »

Nasty. Interestingly the 20th anniversary of the "Braer Storm" has just passed. Esimated pressure of 914mb at it's lowest point.

Yep, I've been posting in the FI thread some of the charts being thrown up recently showing a storm with an even lower pressure than that.

From today's 12Z GFS ensembles :

http://modeles.meteociel.fr/modeles/gens/run/gens-3-1-96.png?12

And a nasty one for us :

http://modeles.meteociel.fr/modeles/gens/run/gens-2-1-114.png?12

Entering into a period of wet and windy weather from the end of this week, potential is there for it to be very windy at times, worth keeping an eye on.

Mr Cumulonimbus

maquiladora wrote: »

Yep, I've been posting in the FI thread some of the charts being thrown up recently showing a storm with an even lower pressure than that.

From today's 12Z GFS ensembles :

http://modeles.meteociel.fr/modeles/gens/run/gens-3-1-96.png?12

And a nasty one for us :

http://modeles.meteociel.fr/modeles/gens/run/gens-2-1-114.png?12

Entering into a period of wet and windy weather from the end of this week, potential is there for it to be very windy at times, worth keeping an eye on.

Wow! Imagine if they tracked to the south of us at those intensities and sucked in a nice frigid easterly. You could have a snowicane!

EDIT: thanks Maq. Hadn't looked into the FI thread before posting the Braer storm chart here. Unaware it was already up there.

Mr Bumble

^^^^
Was thinking the same......maq, is this SSW related??

Luisport

Historic North Atlantic Superstorm Possible for Saturday
.

By Fred Pickhardt On January 23, 2013

NOAA OPC Surface Forecast 12Z 25 January 2013 showing possible historic storm low.

A historic extratropical storm is possible over the central North Atlantic on Saturday, the 26th of January based on the latest computer models. A weak 1014mb low will move off the Virginia and North Carolina coasts early Thursday. It will move rapidly east to northeast, deepening to a 977 mb storm low by 12Z Friday, the 25th, southeast of Cape Race with winds up to 50 knots. Thereafter, this low is forecast to “bomb out” as it moves northeast, dropping 57 mb of pressure to 920 mb by 12Z Saturday, the 26th, with hurricane force winds of 85 knots (nearly 100 mph) likely.

The all-time record for North Atlantic extratropical storms was the Braer Storm of January 1993 that reached a minimum pressure of 914 mb (26.99 in Hg) on January 10th. The 1993 storm caused blizzard conditions across much of Scotland and also led to the final breakup of the oil tanker MV Braer, which had been stranded in rocks off the Shetland Islands by a previous storm.
http://gcaptain.com/historic-north-atlantic-superstorm-remains-likely/

Luisport

Historic North Atlantic Superstorm Possible for Saturday
.

By Fred Pickhardt On January 23, 2013

NOAA OPC Surface Forecast 12Z 25 January 2013 showing possible historic storm low.

A historic extratropical storm is possible over the central North Atlantic on Saturday, the 26th of January based on the latest computer models. A weak 1014mb low will move off the Virginia and North Carolina coasts early Thursday. It will move rapidly east to northeast, deepening to a 977 mb storm low by 12Z Friday, the 25th, southeast of Cape Race with winds up to 50 knots. Thereafter, this low is forecast to “bomb out” as it moves northeast, dropping 57 mb of pressure to 920 mb by 12Z Saturday, the 26th, with hurricane force winds of 85 knots (nearly 100 mph) likely.

The all-time record for North Atlantic extratropical storms was the Braer Storm of January 1993 that reached a minimum pressure of 914 mb (26.99 in Hg) on January 10th. The 1993 storm caused blizzard conditions across much of Scotland and also led to the final breakup of the oil tanker MV Braer, which had been stranded in rocks off the Shetland Islands by a previous storm.
http://gcaptain.com/historic-north-atlantic-superstorm-remains-likely/

Mr Cumulonimbus

Luisport wrote: »

Historic North Atlantic Superstorm Possible for Saturday
.

By Fred Pickhardt On January 23, 2013

NOAA OPC Surface Forecast 12Z 25 January 2013 showing possible historic storm low.

A historic extratropical storm is possible over the central North Atlantic on Saturday, the 26th of January based on the latest computer models. A weak 1014mb low will move off the Virginia and North Carolina coasts early Thursday. It will move rapidly east to northeast, deepening to a 977 mb storm low by 12Z Friday, the 25th, southeast of Cape Race with winds up to 50 knots. Thereafter, this low is forecast to “bomb out” as it moves northeast, dropping 57 mb of pressure to 920 mb by 12Z Saturday, the 26th, with hurricane force winds of 85 knots (nearly 100 mph) likely.

The all-time record for North Atlantic extratropical storms was the Braer Storm of January 1993 that reached a minimum pressure of 914 mb (26.99 in Hg) on January 10th. The 1993 storm caused blizzard conditions across much of Scotland and also led to the final breakup of the oil tanker MV Braer, which had been stranded in rocks off the Shetland Islands by a previous storm.
http://gcaptain.com/historic-north-atlantic-superstorm-remains-likely/

Here's a visible wavelength image of the US eastern seaboard at 18Z. Nothing special to be seen yet. Will all change by Saturday if the models hold true. Jet well illustrated too.

Blizzard 2010

Looks like flooding for parts of England. No sign of a return to the freezer. It will remain changeable though and not overly mild

Luisport

Ryan Maue‏@RyanMaue

Currently at 995 mb -- 6-hourly pressure time series: 987, 980, 963, 935, 922, 919 at tau+36. 65mb/24hours is ferocious/extreme deepening

5 hRyan Maue‏@RyanMaue

GFS back to 919 mb with explosive cyclone off east coast that will move WNW of Iceland during next 36-48 hours. http://twitter.com/RyanMaue/status/294659035070861314/photo/1

Luisport

Matthew Hugo‏@MattHugo81

The low in the W Atlantic goes from 987mb to 938mb in about 18hrs! http://www.wetterzentrale.de/pics/bracka.gif http://www.wetterzentrale.de/pics/brack0.gif - A drop of 49mb! #wow

Luisport

Matthew Hugo‏@MattHugo81

@UKweatherpics - Without question and then some. 24mb fall in 24hrs is a 'bomb' this low is off the scale.

Rikand

is it too soon to predict, but wondering what the weather will be like for the weekend of the 2nd/3rd of February. Is it likely to get cold again or will it be similar to what we are getting this weekend ?

Dead_Rabbits

Rickylovesuall wrote: »

is it too soon to predict, but wondering what the weather will be like for the weekend of the 2nd/3rd of February. Is it likely to get cold again or will it be similar to what we are getting this weekend ?

MT and the general idea among the experts seems to be after the 4 Feb a cold outbreak is likely. None can pin exactly when, maybe around the 4th or out to the 14th of Feb.

Something is defiantly brewing but the detail wont be pinned down till mid/late next week. So keep an eye out here and you will see more activity and details then:)

Dead_Rabbits

Both North Amercian Models are playing off the same hymn sheet. Must bode well as the Western PV is In Their Back Yard.

GEM




GFS




And to follow suit the UKMO minus the low digging in further south over Britain and Ireland.

Elmer Blooker

ME hinting at frosty weather next weekend which indicates pressure building.
We'll see what their week ahead forecast says tomorrow around one pm.

Rikand

hopefully the frost doesnt come in until the 4th - my birthday the weekend of the 2nd and 3rd and dont want frost

Thanks for the early thoughts though