Atlantic Storm Watch: December 2013

ninebeanrows

Hard to imagine that by midday tomorrow a system that is now is barely noticeable could threaten hurricane force winds to parts of the northwest.

Real rapid development.

maquiladora

At 24 hours, 12Z ECM is about 10mb more intense and a bit further south than the GFS.

ninebeanrows

Real headache for Met Eireann tonight.

They really have to call the storm on the 6.1 or 9pm bulletins or they will receive criticism if it comes off.

Would not want to be in their boots tonight with the rapid developments and heightened uncertainty.

This storm is now less than 24hrs from landing its first blow in the west.

JanuarySnowstor

Weathercheck wrote: »

Hard to know where the ECMWF would fit in, other than it is definitely further south than the GFS and looks rather Dangerous for the northwest IMO.

Real risk of Hurricane force wind gusts for the northwest tomorrow.

Yes it's slightly deeper than the UKMO
It's looking a cert for damage in the Northwest

Of course the slightest of nudges South overnight would put us all at risk
Must be proving a nightmare for Met Eireann to call this one accurately
They really need to get a warning out

ninebeanrows

JanuarySnowstor wrote: »

Yes it's slightly deeper than the UKMO
It's looking a cert for damage in the Northwest

Of course the slightest of nudges South overnight would put us all at risk
Must be proving a nightmare for Met Eireann to call this one accurately
They really need to get a warning out

Yes very difficult, but no reason now not to put out a fairly strong worded warning for the northwest.

Slight changes in the timing of rapid cyclogenesis will cause huge differences in path.

Old school weather forecasting needed overnight.

howlinwolf

Weathercheck wrote: »

Real headache for Met Eireann tonight.

They really have to call the storm on the 6.1 or 9pm bulletins or they will receive criticism if it comes off.

Would not want to be in their boots tonight with the rapid developments and heightened uncertainty.

This storm is now less than 24hrs from landing its first blow in the west.

yes they are in a hard spot alright but surely calling it is the right thing to do,all latest signs are pointing to trouble for the north/northwest....if it doesn't come off they will get an ear bashing but im sure they are well used to that by now. better safe than sorry and all that.

maquiladora

Weathercheck wrote: »

Real headache for Met Eireann tonight.

They really have to call the storm on the 6.1 or 9pm bulletins or they will receive criticism if it comes off.

Would not want to be in their boots tonight with the rapid developments and heightened uncertainty.

This storm is now less than 24hrs from landing its first blow in the west.

They called it on last nights forecast. Siobhan mentioned gusts "well over 100 km/h" for the northwest.

Today's 12Z ECM is very similar to yesterday's 12Z, perhaps a touch stronger.

cyclops999

Meteoalarm gone from yellow to orange for Ireland tomorrow.

JanuarySnowstor

I'd say a warning will be issued before 8pm on their website and they will pbly issue one on their tv forecast at 6:55pm

ninebeanrows

ECMWF touches sustained 50-60kts on to coastal northwest tomorrow evening, so gusts to 80kts or above.


Must be noted that a very small area of tight gradient so areas southeast of Ulster/North Connacht would not be greatly affected going off latest ECMWF.

ninebeanrows

maquiladora wrote: »

They called it on last nights forecast. Siobhan mentioned gusts "well over 100 km/h" for the northwest.

Today's 12Z ECM is very similar to yesterday's 12Z, perhaps a touch stronger.

Yes but not an official warning, or fore-warning issued on their site whatsoever.

maquiladora

Weathercheck wrote: »

Yes but not an official warning, or fore-warning issued on their site whatsoever.

Considering how many times the title of this thread has changed from Level 1 to Level 2 over the past 48 hours, maybe its better to wait before issuing a warning.

Anyway, the warning is on Meteoalarm now so it should appear on the Met Eireann site soon.

"Southwesterly winds will increase 60 to 80 km/h and will gust 100 to 120 km/h., in exposed coastal areas of Galway, Mayo, Sligo, Leitrim amd Donegal, later Wednesday afternoon and for a time Wednesday night."

M.T. Cranium

You can see some signs of the developing storm on satellite imagery, I estimate the centre to be near 50N 39W and there is a trace of squall line development ahead of that around 36W. A ship located well south of the centre around 39N has a southwest wind of 40 kts and is at 22 C. No ships well located at this time for useful readings next 6-12 hours, it would seem, so satellite imagery will be our main source of information.

I have the same general impression as most of you seem to have, a slight upgrade with GFS blinking at this point while the GME has the most robust solution.

Agree that most of the impacts will be north of a Clare to Dublin line and max gusts likely to be around 70 kts Mace Head and possibly 80 kts Belmullet, these around 9 p.m (Wed). Dublin could have a brief period of 60-65 kt gusts around midnight. North Ulster also closer to midnight and lasting well into the night for max gusts as storm could be even stronger in western Isles, so 85 kts Malin Head around 0200h my call there.

All of that subject to a possible 20-30% downgrade if GFS has best handle, don't see much chance of an upgrade to these values. This suggests scattered reports of fairly minor damage such as trees down, tiles off roofs, and in general would advise against travel in the areas outlined during the period 7 p.m. to end of event late overnight. There could also be some issues with Atlantic trying to subdue coastal defences at high tide, there again, probably relatively minor issues not quite at the "storm surge" level.

The intense looking systems later in the period will probably be shifted north and downgraded, while the weather may not be as mild as last week, it will probably be a bit milder than it looks on the charts as the Atlantic tirelessly modifies stale arctic air from distant sources. Any given event could suck in a rather mild sector as per tonight and tomorrow morning. Snow will sometimes be seen as low as 200-300 m between systems but may be largely absent from direct contact with most of the public unless they go out of their way to find it.

Weathering

Yes but perhaps they could issue an Advisory instead of a warning in times of uncertainty like this past few days. I don't know what the criteria requirements are for such advisories but I believe the Met office issue them when there is a 40pc chance of severe weathering occurring. I'm no expert but I imagine we've already met the UKMO criteria for an advisory

maquiladora

ECM with a 937mb low off the north coast on Stephens Day.

ninebeanrows

Siobhan issued a pretty strong forecast at 6.1

maquiladora

Still worth pointing out that if the 12Z GFS is right, then tomorrow will be a complete non-event, with gusts on even exposed coasts no stronger than they are right now this evening.

Hooter23

Hopefully it will come even closer cause the area of strong winds looks very small for this storm for some reason.
The monster storm near christmas time has been showing up quite alot on some charts would be a nice Christmas present if it happened although it looks abit too extreme we might be all homeless a week from now :pac:

ninebeanrows

Well the ECMWF mean was slightly further south than the Operational leading to further reason to believe the GFS projection is an outlier.

ninebeanrows

WZ comparison might be better.

1) Operational ECMWF



2) Mean ECMWF

maquiladora

Very strong signal for deep low pressure dominating the Christmas period on the ECM ensembles.

TheDoctor

We're all going to die!!!!!!!!!!!!!!!!!!!!!!!!!

rickdangerouss

TheDoctor wrote: »

We're all going to die!!!!!!!!!!!!!!!!!!!!!!!!!

Yes we are, at some point in time.

kkontour

maquiladora wrote: »

Very strong signal for deep low pressure dominating the Christmas period on the ECM ensembles.

Reminds me of the day after tomorrow movie. Where the big lows pull down freezing cold air.

maquiladora

Weathercheck wrote: »

WZ comparison might be better.

Mean has a tighter gradient than the op?

ninebeanrows

maquiladora wrote: »

Mean has a tighter gradient than the op?

Yea looks a bit quirky to me. Probably best to use the Meteociel site.

Who wants to trawl through the postage stamps!? Not much use at the 24hr interval, although majority actually further south (obviously very marginally on them maps) than the high res.

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2013021500!!/

Oscar Bravo

STATUS ORANGE

Wind Warning for Galway, Mayo, Sligo, Leitrim, Donegal.

South to southwest winds will increase 60 to 80 km/h and gust 100 to 120 km/h., later Wednesday afternoon and evening, in exposed coastal areas of Connacht and Donegal.
Issued:
Tuesday 17 December 2013 20:00

Valid:
Wednesday 18 December 2013 15:00 to Wednesday 18 December 2013 23:59

JanuarySnowstor

Seen enough to expect an upgrade on tonights 18z.
Here goes up in 5 mins

ninebeanrows

18z GFS sticking quite similar to 12z and quite significantly different to ECM/UKM/JMA take on it.

JanuarySnowstor

Storm......what storm says gfs.
Continues to show a weaker option on 18z