Atlantic Storm Watch: December 2013

Mr Cumulonimbus

maquiladora wrote: »

Also it looks like NAE does not display pressure below 950mb on Weatheronline.

I'm not even going to attempt to hazard a forecast at this stage :pac:

Maq, surface pressure only charts going below 950mb it seems. Nasty!

@MT. Seems roughly like a 16mb gradient going from NW to SE, interpreting NAE chart?

Oscar Bravo

its five to midnight, met eireann time on Radio 1.....sky 0160

Weathering

27th looks breezy too

maquiladora

Mr Cumulonimbus wrote: »

Maq, surface pressure only charts going below 950mb it seems. Nasty!

Ah, thanks. Odd that it doesn't display below 950mb on the other output.

Mr Cumulonimbus

Oscar Bravo wrote: »

its five to midnight, met eireann time on Radio 1.....sky 0160

Well, no preliminary indications of the meteorological equivalent of an incoming nuclear attack in that forecast. ME playing it safe still. Not even "storm force" mentioned in the sea area forecast outlook to midnight Monday.

maquiladora

Mr Cumulonimbus wrote: »

Well, no preliminary indications of the meteorological equivalent of an incoming nuclear attack in that forecast. ME playing it safe still. Not even "storm force" mentioned in the sea area forecast outlook to midnight Monday.

Here's the latest Met Office shipping forecast outlook.

During Monday evening, a very deep low 939 is expected to be centred over the north of sea area Rockall. This low moves slowly northeast to lie over sea area Hebrides 932 by Tuesday morning and then north to lie near the Faeroes 939 by midnight on Christmas Day and then filling slowly as it moves away northwards into the Norwegian Sea by midday on Boxing Day. By Boxing Day evening a new very deep low 950 is expected to approach the western boundary of sea area Rockall. Strong winds or gales are expected in all areas for most of the period with severe gales or storms likely at times from Monday evening to early on Christmas day and perhaps even violent storms for a time in Rockall, Malin and Hebrides. Severe gales or storms are also possible at times in most areas later on Boxing Day

Mr Cumulonimbus

maquiladora wrote: »

Here's the latest Met Office shipping forecast outlook.

Wow, "932 off Hebrides". I'll actually be in the middle of any potential action on Monday. Heading down to the parents house in West Mayo tomorrow morning. Place is called Murrisk, 6 miles outside Westport. Croagh Patrick is to the south, with the village at the bottom of a downslope from the foot of the mountain itself. I believe it may suffer from the lee wave formation effect that MT mentions in post #1742. SE, S, and SW gales are unpleasant there. Lots of calms and then vicious squalls of wind. W and NW gales are more constant, coming in off the sea itself.

Sierra Oscar

Not surprised Met Éireann are playing it safe considering they are forecasting for one of the busiest days of the year travel wise, plenty of time for them to upgrade tomorrow if the trend is bleak looking.

dacogawa

Still on track & seems to have moved a little bit more south

Weathering

Did someone say blizzard?





Take with a pinch of salt

Weathering

maquiladora

The 48 hour Atlantic surface forecast has been issued, and the pattern is expected to remain active. Check out the INTENSE hurricane force low in the eastern Atlantic with a central pressure of 924 hPa! 

http://www.opc.ncep.noaa.gov/shtml/A_48hrbw.gif

red_bairn

maquiladora wrote: »

http://www.opc.ncep.noaa.gov/shtml/A_48hrbw.gif

Somebody mistakenly typed up hurricane there...

maquiladora

red_bairn wrote: »

Somebody mistakenly typed up hurricane there...

Hurricane force (Beaufort 12) winds. Not a mistake, common with deep north atlantic lows.

The pressure of 924 really is exceptional though. Might not ever see a low so deep so close to our isles again for a long, long time.

red_bairn

maquiladora wrote: »

Hurricane force (Beaufort 12) winds. Not a mistake, common with deep north atlantic lows.

The pressure of 924 really is exceptional though. Might not ever see a low so deep so close to our isles again for a long, long time.

*gulp*

Well I prefer wind over a non-event. Things have became quite interesting over the last week.

maquiladora

red_bairn wrote: »

*gulp*

Well I prefer wind over a non-event. Things have became quite interesting over the last week.

Could still be close to a non-event in terms of wind here. Met Eireann are only going for "windy/blustery" tomorrow.

The strongest winds I ever experienced were from a 980-975mb low, so its not all about the pressure, its about the pressure difference over an area.

Weathering

Where did Ireland go?

JanuarySnowstor

Widespread disruption looks inevitable xmas eve with gusts over 100mph coupled with heavy snow showers.
Met eireanns web forecast is a joke

Mr Cumulonimbus

Looking at the 6Z GFS run, it seems now the worst winds maybe on Tuesday morning. Low centre seems to be a bit further away now for Monday itself.

0600 GMT NAE out as well. 1800 GMT tomorrow evening:



0600 GMT Tuesday morning:

munsterlegend

Met Eireann's forecast really plays it down as it stands. I suppose they will wait until this afternoon before deciding on any warnings.

acassells80

JanuarySnowstor wrote: »

Widespread disruption looks inevitable xmas eve with gusts over 100mph coupled with heavy snow showers.
Met eireanns web forecast is a joke

Are snow showers confined to the north and west or will Dublin and East Coast see any flurries??

John.Icy

GFS 6z is definitely a huge upgrade in terms of severity on Tuesday. It's going to be a real tough one to forecast.

In fairness to Met Eireann they updated their forcecasts according to yesterdays runs and yesterday didn't look hat bad.

The ECM this morning doesn't look that bad at all, though we miss key frames to see where the storm actually tracks. but it looks like keeping well North.

GFS 0z was wicked for Friday, while ECM was run of the mill stuff. So much to keep an eye out for.

Netweather has severe gales for Tuesday morning.

maquiladora

John.Icy wrote: »

GFS 6z is definitely a huge upgrade in terms of severity on Tuesday. It's going to be a real tough one to forecast.

In fairness to Met Eireann they updated their forcecasts according to yesterdays runs and yesterday didn't look hat bad.

The ECM this morning doesn't look that bad at all, though we miss key frames to see where the storm actually tracks. but it looks like keeping well North.

GFS 0z was wicked for Friday, while ECM was run of the mill stuff. So much to keep an eye out for.

You can see the ECM track here, it loops anticlockwise Monday-Tuesday.

http://en.vedur.is/weather/forecasts/atlantic

John.Icy

maquiladora wrote: »

You can see the ECM track here, it loops anticlockwise Monday-Tuesday.

http://en.vedur.is/weather/forecasts/atlantic

Thanks Maq, comes abit closer to shore than you'd think from the 48-72 hour frame.

whitebriar

John.Icy wrote: »

Thanks Maq, comes abit closer to shore than you'd think from the 48-72 hour frame.

Yes but as Maq pointed out ,the gradient is not big enough to merit concern unless there's a change.
So a bit on the windier side of a normal Irish wet day for most ie thankfully boring in my opinion.

maquiladora

John.Icy wrote: »

Thanks Maq, comes abit closer to shore than you'd think from the 48-72 hour frame.

And that track isnt nailed yet, this thing is still developing.

Either way this will be a low with a very wide wind field with gales extending far, far from the center.

In some of the historic storms of the past, their tracks were no closer to the north coast than what some of the models show now, and with comparable MSLP too.

ninebeanrows

GFS 6z is an upgrade in terms of intensity, it appears the windfield will gather and the pressure gradient tighten to our west during Monday (which will be a windy but not severe day). The overnight Monday and into Christmas eve the tight gradient could push ashore with some severe wind gusts.

Pushing the dangerous period of this storm into Christmas Eve will also increase headaches with regard to potential power disruption etc.

Cosmo Kramer

Quick question for someone who knows more about this than me. The pressure to the north west of Ireland is set to fall to unusually low levels over the next 48 hours, but wind speeds will be determined more by the extent of change in pressure over the area rather than the pressure itself.

In that case, will there be any noticeable difference to the Irish weather over the next 48 hours specifically as a result of the pressure being so low, or is the exceptional low more a case of something that looks more spectacular on a map but might not be so noticeable in reality?

maquiladora

Worth pointing out that the GFS is showing a potential damaging storm for the 27/28th. Though there is more uncertainty with that.