Atlantic Storm Watch: December 2013

maquiladora

The ECM does indeed look fairly stormy for the west coast on the Weather Underground. It's 948mb at 75 hours, storm force winds along the coast but of course much less severe further inland.

Interestingly between 60-70 hours its actually 2 areas of low pressure which merge. That might be what is adding to the model uncertainty.

ninebeanrows

maquiladora wrote: »

The ECM does indeed look fairly stormy for the west coast on the Weather Underground. It's 948mb at 75 hours, storm force winds along the coast but of course much less severe further inland.

Interestingly between 60-70 hours its actually 2 areas of low pressure which merge. That might be what is adding to the model uncertainty.

From experience them charts underestimate the extend of wind speeds inland.

Nice swathe of 50-60 knot mean speeds for the west coast though.

diceyd

Britains killer storms on at half 7 tonight on ch.4

maquiladora

40 kt wind barb over the midlands.

M.T. Cranium

Keep in mind also that with full moon on the 17th, storm surge potential would be quite high on 18th and 19th at high tides. On the current ECM track that would be of particular concern for Galway Bay and harbours around the coast north to Belmullet.

This potential system is beginning to take form as a trailing wave over the Great Lakes region (the primary low is near the southwest tip of Nova Scotia now) which would phase with energy available along a trailing cold frontal wave now west of Bermuda. This phasing would not really begin until Tuesday morning east of Newfoundland.

About the Dec 26, 1998 storm, some similarity but that one tracked more east than northeast at the critical landfall stage and this allowed damaging wind gusts to spread inland over most of Ireland. Even on the more dire versions of the approaching storm, the damaging gusts would probably be less severe across the south, although with that gradient coming so close to landfall, we cannot be too precise this far out and should stress the potential for perhaps a level 2 alert over much of the country and level 3 for the Connacht and west Ulster coastal regions -- we all know that strong winds are commonplace there but this event could be a level above most recent storms. This one is still in a developing phase at closest approach (which currently looks to be 9 p.m. Wednesday) and suggests possible gusts above 90 knots in exposed locations. My early estimate for Galway to Dublin inland wind gusts would be 65 knots plus or minus 10. South coast 60 plus or minus 10. With this much model consensus (GFS,ECM,GEM very much in line) I tend to think the UKMO has missed a signal and can be discounted.

maquiladora

Something to keep an eye on for sure, though I'm not yet convinced the ECM solution will be the final version of what happens, but at just 72 hours it can't be discounted either. (Though the UK met office fax charts seem to be discounting the 0Z ECM at least).

Iancar29

SLightly off topic but....


Happy Christmas???? :eek:

gozunda

Iancar29 wrote: »

SLightly off topic but....


Happy Christmas???? :eek:

Drat - Santa ain't got any chance of getting thru that one
NORAD will have their work cut out tracking him this year

Dan man

Iancar29 wrote: »

SLightly off topic but....


Happy Christmas???? :eek:

That black area covering Ireland might just be a forecast of the black smoke that will start billowing from my oven after I've burnt the Christmas dinner!! I'm having nightmares already!

Seriously though, looks interesting to say the least!

ninebeanrows

Lots of support for the ECMWF Op in the ensembles

We could be looking at most severe storm for some years, and I don't think it will be just the north and west hit, think it will be widespread.

maquiladora

Weathercheck wrote: »

Lots of support for the ECMWF Op in the ensembles

We could be looking at most severe storm for some years, and I don't think it will be just the north and west hit, think it will be widespread.

Strongest since Decemeber 2011 maybe, though probably not quite as intense as that:

ninebeanrows

18z GFS still has storm on route.

ninebeanrows

Windy:

maquiladora

18Z GFS increases the intensity a bit. Touching Force 12 on the exposed west coast on this run. Take down the christmas tree in Belmullet.

Harps

Looks like quite a severe storm though mainly limited to the north west, Jan 12 and the two storms in Dec 11 were all equally if not more severe than what's being forecast and only caused minor damage and power outages in the NW so I wouldn't say anything too dramatic is on the way. Should be interesting though and definitely one to prepare for

Shame it's not happening a week later so I could experience it's full force!

Weathering

18z GFS brings 80-90mph gusts over the N&NW

leahyl

Weathering wrote: »

18z GFS brings 80-90mph gusts over the N&NW

Doesn't look too bad for much of the rest of the country (apart from North)

tylercollins

leahyl wrote: »

Doesn't look too bad for much of the rest of the country (apart from North)

Yeah the north is going to get a serious hammering! Hopefully not too much damage is caused.

maquiladora

leahyl wrote: »

Doesn't look too bad for much of the rest of the country (apart from North)

If that model was right, it would be stormy from the southwest to the north. The west and northwest coasts would get the strongest. (130-160 km/h gusts)

shmaupel

I'm in SW Donegal. My front door is about 30m from high tide. Used to the wind naturally, but this looks menacing.

There's nothing to beat the power of the Atlantic at full tilt but hopefully we can enjoy a good display from Mother Nature without anything tragic happening.

Mech1

Just a little reminder what with all this wind forecast, you can tune in to my Dublin Air Traffic Control feed by following the link in my signature.
Its the first one of the three Dublin feeds.

Oneiric 3

Monthly MSLP and 2m temperature means for January 1974, one of the stormiest months on record. Exceptionally tight isobaric gradient over the north Atlantic, initiated no doubt by the tight temperature gradients created by cold north American air coming in contact with warm Atlantic air. Not unlike the present set up, though far more enhanced.

Jan 1974 saw a number of significant storms hit Ireland, with gusts of 70 kt + experienced not just on the coast, but overland as well on more than one occasion.



From ERA-40

maquiladora

0Z GFS. These are sustained winds, not gusts.

Reaching 80-84 mph on the west coast, that's sustained winds of 130+ km/h. The criteria for a red warning from Met Eireann is sustained winds of 80+ km/h.

If this came off it would be a notch above the typical winter storms we see every year, even for exposed coasts.



This is a very tight gradient over Ireland. Damaging wind gusts would not be limited to coastal areas if this happened.



But....

On the other hand, the 0Z UKMO is very different from the GFS, showing a much weaker development and no storm at all really. The UKMO is one of the top 3 global models and you cannot ignore it at 60 hours, and none of the other 0Z models that are out show something quite as strong as the GFS does. We'll see what the ECM does later.



Edit : 0Z ECM is out and it develops a strong low like the GFS. 947mb just west of Scotland at 72 hours, however the ECM has a narrower swathe of strong winds and they are further north compared to the GFS, more of a coastal/northwest event, though we'd need to see what happens between 63-72 hours.

cherryghost

ECM is in agreement this morning so it seems with the GFS, almost identical charts.

dopolahpec

We seem to miss a key stage in storms development on ECM this morning. Though it then shows it developed having moved across the country. Certainly a lot more severe than UKMO but doesn't look to have quite the vicious intensity of the GFS but can't say for sure.

Time for warnings?

Weathering

Merry Xmas, hopefully Santa will be okay

M.T. Cranium

Then there's the jaw-dropper at day 9 (25:00z) on ECM which would basically obliterate half the country -- sub 940 mb low inland over Connacht -- expect plenty of changes in this one over next five days as the chance of that verifying is obviously very low, all it means at this point is that the timing of waves coming out of eastern North America is continuing to average about 3.5 days and this particular one has phased with long-wave troughing. I would expect this to transform into a more normal looking 970 mb low further north over time. Let's hope so anyway.

maquiladora

0Z GFS and ECM at 63 hours agree on a 954mb low centered roughly in the same area.

However, there is a big difference between the two models on the size of the windfield. ECM has a much smaller windfield that brushes the west/northwest coast. Still stormy, but not as severe or widespread as the GFS winds. ECM would be a more typical west coast winter storm.

Same scale and timeframe. Spot the difference.



And yes, deep in FI, but Christmas Day would be cold turkey by candlelight for a lot of people if this happened.

M.T. Cranium

Hoping that a moderator could edit the original post title as it should probably now be a level 2 with title something like Potential for Strong Windstorm late Wed 18th (and future events to Christmas Day).

Weathering