Potential Storm Watch Fri 7 Dec 2018

Meteorite58

squarecircles wrote: »

Surprised nobody's mentioned this evenings ECM, gusts of up to 150kmh in west/northwest for friday
If this evolved as it's being shown,Gfs 12z also had a severe windstorm just to the north of Donegal bay ,would be nasty if it were to continue to drift further south

Saw that squarecircles , some potent looking charts there all right. GFS and ICON dropped the storm on last night's run but back again today, GFS as you say further North and ICON bringing the winds in over Ireland, now that is something you don't see everyday... ECM similar strength winds to ICON ! The shape of these systems is changing over the last few runs but strong winds showing up at some stage in some part of Ireland by the looks of it. Of course still time to drift further North but has the look of making some contact I think. Even got an early mention on the weather forecast last night after the news showing a chart with a severe storm and mentioning potential for extremely strong winds.

The Jet powering up this week will lead to some unpredictability with this storm system.

Probably now is a good enough time to start a dedicated Storm Watch Thread to keep a close an eye on this.

Current ECM 12Z : Fri early morning shows a deepening storm just off the NW. Continues windy until further very strong winds arrive later in the day from another vigorous wave like system developing from the main storm .

ECM has been the most consistent with this over the last few days I reckon.

All open to change one way or the other over the next few days.

Meteorite58

ICON strongest most direct impact winds of the bunch.



Still a bit out of the reaches of ARPGEGE atm, showing the strongest winds missing us on this run . More accurate in a day or so , one way or the other .

Meteorite58

Turning much cooler Fri after a relatively mild Thurs . Wintry precipitation perhaps on high ground. Looks like convective potential bringing hail and heavy showers and perhaps thunderstorms. To me has the look of being a harsh day feeling raw in the wind.

squarecircles

18z brings the core of the strongest winds further south,grazing the west and northwest

RobbingBandit

Lock up your daughters and trampolines it's gonna get wild

Meteorite58

At this far out UKMO and NOAA very similar.

uck51js9zml2yt

Feck...if you guys didn't post these threads,we wouldn't be having these storms....instead it would just be breezy with a lot of rain....;)

Meteorite58

The Jet picking up this week , powering up and steering the systems close to us.

M.T. Cranium

Still some scatter in the guidance, the GFS and GEM both have a fairly severe looking gradient by Friday 0300-0600h.

The general set-up and date remind me of one of Ireland's worst ever wind storms, 8 Dec 1886. A record low pressure in the 920s was observed in Ulster, much damage was reported in Ireland and northwest England, and ships were sunk in the Irish Sea. The map from the wetterzentrale archive, while accurate in general, fails to show the last few isobars around the centre so it was even more fierce than it looks here:

http://www.wetterzentrale.de/reanalysis.php?map=1&model=noaa&var=1&jaar=1886&maand=12&dag=08&uur=1200&h=0&tr=360&nmaps=24#mapref

(hope that works, if not, navigate to 12z map on 8 Dec 1886).

Not saying this will repeat, but it's the sort of west-to-east track that exposes all of the country to severe wind gusts blowing through gaps in the terrain from Atlantic to Irish Sea.

If there is good model consensus on this later today an advance alert will likely be issued. I have mentioned potential for gusts to 120 km/hr but that might be conservative if some guidance verifies.

derekon

M.T. Cranium wrote: »

Still some scatter in the guidance, the GFS and GEM both have a fairly severe looking gradient by Friday 0300-0600h.

The general set-up and date remind me of one of Ireland's worst ever wind storms, 8 Dec 1886. A record low pressure in the 920s was observed in Ulster, much damage was reported in Ireland and northwest England, and ships were sunk in the Irish Sea. The map from the wetterzentrale archive, while accurate in general, fails to show the last few isobars around the centre so it was even more fierce than it looks here:

http://www.wetterzentrale.de/reanalysis.php?map=1&model=noaa&var=1&jaar=1886&maand=12&dag=08&uur=1200&h=0&tr=360&nmaps=24#mapref

(hope that works, if not, navigate to 12z map on 8 Dec 1886).

Not saying this will repeat, but it's the sort of west-to-east track that exposes all of the country to severe wind gusts blowing through gaps in the terrain from Atlantic to Irish Sea.

If there is good model consensus on this later today an advance alert will likely be issued. I have mentioned potential for gusts to 120 km/hr but that might be conservative if some guidance verifies.

Thanks for the update MT. You mentioned in your daily forecast this morning that we are heading into a cool dry period once the stormy weather abates late Friday.

After that, you have pegged the period 21st-23rd as potentially stormy. From your research , is Ireland on course for a cold snap in the last week of December? I know you issued preliminary thoughts on the upcoming winter for Ireland but do you anticipate issuing a final winter forecast over the coming week?

Believe it or not, it's one of the highlights of the year here on weather boards!

Thanks
Derek

squarecircles

Latest weather models show an increasingly likely chance that Ireland will receive damaging winds from an intense Atlantic storm depression later this week.

That's according to Midlands Weather Channel expert Cathal Nolan, who posted his latest findings on social media this morning.

"While the storm is a considerable time away at present, early estimates suggest that if the storm system develops as projected, then wind speeds may gust between 140 - 16o km/hr across parts of May, Sligo, Leitrim, Donegal, Derry and Antrim, where status red warnings would in all likelihood be issued," said Mr Nolan.

And it would be rough across the rest of the country too, with winds elsewhere expected to reach between 120 and 140 km/hr which, according to Mr Nolan, would mean widespread orange weather warnings would also be issued, should the potential storm develop as indicated by the latest weather models.


"What makes this storm particularly dangerous in comparison to more recent storms is the fact that it’s projected to develop rapidly close to Ireland, meaning it’s full affects will be felt, and also there exists a higher chance of witnessing sting jet development also," he said.

A sting jet is a meteorological phenomenon, which can cause severely damaging winds.

DOCARCH

squarecircles wrote: »

Midlands Weather Channel...

Hmmmm....

Cee-Jay-Cee

We are supposed to travel from Donegal to Dublin on Friday at midday to go to the zoo for the Christmas lights show however I'm having doubts as whether that's wise or not given the potential weather expected. Can anyone advise whether Dublin will see storm conditions?

Rebelbrowser

Cee-Jay-Cee wrote: »

We are supposed to travel from Donegal to Dublin on Friday at midday to go to the zoo for the Christmas lights show however I'm having doubts as whether that's wise or not given the potential weather expected. Can anyone advise whether Dublin will see storm conditions?

No one will have any clear idea until Thursday really

Meteorite58

Big spread in the models this morning with a lot of uncertainty. ECM showing weaker winds on the latest run , up to 110 -120 km/h on coasts , Others showing strongest winds in the NW 110 - 130km/h , more so on the coasts. Windy day across Ireland,up to 80 - 90 km/h in general but timing , track and strength all to be ironed out with more changes over the coming days.

Nobody can say for certain atm which way this will go.

VW 1

Cee-Jay-Cee wrote: »

We are supposed to travel from Donegal to Dublin on Friday at midday to go to the zoo for the Christmas lights show however I'm having doubts as whether that's wise or not given the potential weather expected. Can anyone advise whether Dublin will see storm conditions?

Given the lack of certainty on the severity weather event, and the fact it isn't for several days, hold off and play it by ear. If on Friday morning there are advisories not to travel, don't travel.

Sycamore Tree

DOCARCH wrote: »

Hmmmm....

Yeah the midlands weather channel always seems to overegg these storms considerably leading to disappointments.

jirafa

Perhaps a few questions answered here, both short term and early Winter .

What will influence our winter weather? - The Weather Studio

Rebelbrowser

The GFS, UKMO and GEM 12z output all seem to move this northward so its more of a NI / UK Midlands and northward event. Still very windy from our own midlands northward but not a direct hit by any means.

jasper100

Rebelbrowser wrote: »

The GFS, UKMO and GEM 12z output all seem to move this northward so its more of a NI / UK Midlands and northward event. Still very windy from our own midlands northward but not a direct hit by any means.

Good news. I can do without the BS of RTE ramping it relentlessly with a prime time special then an empty studio for the late late show with just a gentle breeze outside.

Clonmel1000

jasper100 wrote: »

Good news. I can do without the BS of RTE ramping it relentlessly with a prime time special then an empty studio for the late late show with just a gentle breeze outside.

RTE ramping? That’s a bit harsh given what occurs on boards and elsewhere at times in fairness.

Meteorite58

A split in the camp between the ECM and the other group of models . From what I can make out the ECM on this run is not showing the earlier Low develop until it has passed Ireland Thurs night , not showing any winds of note early Fri morning. This is a big departure from earlier runs so might be an outlier. It shows the secondary low Fri evening bringing strong winds for a time more across the Southern half of the country , fast moving system.

GFS, ARPEGE, ICON , GEM and WRF all showing strong winds late Thurs night / early Fri morning more so in the NW /N but they differ in strength and track and all go on to show strong winds in one shape or form later Fri afternoon/ evening but again difference in track.

For the record ICON showing a fairly strong storm move up along Atlantic coasts early Fri morning, it goes on to track near Northern coasts and move across through N UK / Scotland , brings the strong winds in across the W , NW and Northern counties producing stormy conditions gusting up around 130 km/h and more on coasts. This was roughly the track being shown by the ECM originally too, I wonder will the ECM come back to something similar . This track has similarities with what the other models are showing also . ICON showing the strongest winds but these could tone down a bit.

Met Eireann : Thursday night: Rain becoming widespread on Thursday night, accompanied by increasingly windy or possibly stormy conditions for a time as southwesterly gales develop

Friday: Bright spells and scattered blustery showers for Friday. Some of the showers will be heavy with a risk of hail and thunder, possibly merging to longer spells of rain later in the day. Southwesterly winds will decrease fresh to strong and gusty for a time but again the potential for gales force winds through the latter half of the afternoon and evening, as winds veer northwesterly. Cooler, with afternoon highs ranging 5 to 8 degrees.

M.T. Cranium

The evolution is complex, but as of now, a 975 mb low sits south of Greenland at 55N 50W. (18z CMC analysis)

Given that there's a lot of "dead" synoptic patterns in various regions of the hemisphere, this could become a near-time explosive developer and those usually don't tip their hand very far in advance. There will be a strong energy peak with the new moon timed for 7th at 07z, so I would not take this too lightly (yet).

This recent map of SST values shows a strong thermal gradient near where this storm is developing.

https://www.ospo.noaa.gov/data/sst/anomaly/2018/anomnight.12.3.2018.gif

tikkamark

M.T. Cranium wrote: »

The evolution is complex, but as of now, a 975 mb low sits south of Greenland at 55N 50W. (18z CMC analysis)

Given that there's a lot of "dead" synoptic patterns in various regions of the hemisphere, this could become a near-time explosive developer and those usually don't tip their hand very far in advance. There will be a strong energy peak with the new moon timed for 7th at 07z, so I would not take this too lightly (yet).

This recent map of SST values shows a strong thermal gradient near where this storm is developing.

https://www.ospo.noaa.gov/data/sst/anomaly/2018/anomnight.12.3.2018.gif

I’m no means a weather expert and I know it’s probably not very accurate but you can see that area of low pressure at the tip of Greenland very clearly on the windy app at the moment,it’s saying it’s going to stay in or around that spot until roughly Thursday it’s being fed by currents coming along the east coast of Greenland as it breaks away from that spot and heads our way it looks to be gathering serious energy

Meteorite58

Latest GFS 18Z and ICON 18Z now leaning towards the ECM 12Z . ICON looking nothing like the earlier stormy chart.

M.T. Cranium

You know if the GFS and ICON can't find a storm, there's no storm.

ninebeanrows

Significant run to run change from EC.

Stormy for northwest on this run from T48hrs

Xenji

Status Yellow - Wind warning for Connacht, Cavan, Donegal, Clare, Kerry and Limerick
Southwest winds will reach mean wind speeds between 55 to 65km/h with gusts of 90 to 110km/h, strongest near coasts where these limits may be exceeded for a short period later on Thursday night.

Issued: Wednesday 05 December 2018 12:00

Updated: Wednesday 05 December 2018 12:00

Valid from Thursday 06 December 2018 22:00 to Friday 07 December 2018 09:00

typhoony

quite a potent little system off the NW Coast this friday, wouldn't be surprised if there's a Orange\Red alert up there. 90mph gusts just off the far NW coast and North coast of N.Ireland

pauldry

Yes a very possible 140kph in the Northwest or Malin

.....on present charts

Meteorite58

Just taking a look through the charts on the phone also and I would think that they have increased wind speeds over the last two runs, the system early Fri morning a lot closer to the NW coasts. Wouldent be surprised to see wind speeds increase more. Fri looking very windy and squally across the country.

Meteorite58

Meteorite58 wrote: »

Just taking a look through the charts on the phone also and I would think that they have increased wind speeds over the last two runs, the system early Fri morning a lot closer to the NW coasts. Wouldent be surprised to see wind speeds increase more. Fri looking very windy and squally across the country.

12Z GFS doesn't seem as severe as the 6Z run.

Oscar Bravo

Siobhan Ryan on the weather there, "pressure will fall from 1000 down to 983 with rapid cyclogenesis occurring, every chance now the warning will be upgraded to Orange"

Tomtom364

Is Friday evening looking likely to have disruptive weather aswell or is it looking like a mostly Thursday night Friday morning event?

squarecircles

Personal note to oneself - now cast situation,explosive cyclongenesis,(bombogenesis)severe local conditions,sting jet,damaging winds in west/northwest,egg on face.

Orange warning imminent.



Rest of the country-tut shore it wasn't bad at all

Cue warning criteria debate.

Meteorite58

Cant post charts atm but have a look at the HIRLAM , severe along the W , NW , N coasts early Fri morning.

squarecircles

Tomtom364 wrote: »

Is Friday evening looking likely to have disruptive weather aswell or is it looking like a mostly Thursday night Friday morning event?

There is potential for a second bout of severe winds across the south and west Friday evening,stay tuned to your local forecast and keep up to dat with met.ie warnings which maybe upgraded by morning time

squarecircles

https://www.donegalweatherchannel.ie/news/weather-bomb-storm-status-orange-wind-warning-likely-to-be-issued-for-the-northwest-and-west-of-ireland

Sycamore Tree

Meteorite58

Meteorite58 wrote: »

Cant post charts atm but have a look at the HIRLAM , severe along the W , NW , N coasts early Fri morning.

Yep, looks nasty for a while. Mean speeds of 100+ km/h in the coastal areas of the W & NW for a time if accurate.



Adding the FMI-HIRLAM chart for gusts. 140 km/h possible, reaching into inland areas of NW Mayo first and then into Donegal.

Projected 15 millibar pressure differential between Westport (990) and the tip of NW Donegal (975) in the early morning. Almost 30 mb difference from NW Donegal to SW Cork.

Meteorite58

The ECM showing some very strong winds along the W and NW coasts, 110 to 130 km/h or perhaps even a bit higher. The European models are keeping the track closer to the Irish coast , American a bit further out and less strong. Would side with the European at this stage. If the storm tracked even 60 km closer it would bring very strong damaging winds inland. Hard to know if it will do so, it seems to have settled into the shown track atm...we will see. As squarecircles said it is coming down to a nowcast.

Meteorite58

Meteorite58

ARPEGE track very similar to the ECM but a bit less strong.

HIRLAM has the closest track and probably strongest winds on the present run, would be inclined to trust the HIRLAM over the ARPEGE. The HIRLAM would bring severe damaging winds to W Galway, Mayo, Sligo, NW Leitrim and Donegal if this were to verify. Don't know if it will . I think very possible to see Orange warnings at least by tomorrow unless the system takes a track further out. Close.

Meteorite58

HIRLAM 18Z 10m Mean Wind Speeds ( kt)

Meteorite58

ECM along with the rest of the models slight shift W with the track keeping the strongest winds out over the sea and just skimming the coasts.. Yellow warnings look set to remain as of now I reckon. The track looks fairly set .

Meteorite58

Meteorite58 wrote: »

ECM along with the rest of the models slight shift W with the track keeping the strongest winds out over the sea and just skimming the coasts.. Yellow warnings look set to remain as of now I reckon. The track looks fairly set .

Yep, 0Z HIRLAM keeps the strongest winds a bit further West than the previous run.

ninebeanrows

MetE played this one very well as usual it seems

Oscar Bravo

Status Yellow(update 1043) - Wind warning for Connacht, Cavan, Donegal, Clare, Kerry and Limerick

Southwest winds will reach mean wind speeds between 55 to 65km/h with gusts of 90 to 110km/h during the period, strongest near coasts where these limits may be exceeded at times.

Issued: Wednesday 05 December 2018 12:00

Updated: Thursday 06 December 2018 10:43

Valid from Thursday 06 December 2018 22:00 to Friday 07 December 2018 12:00

CrowdedHouse

Gone orange for Donegal and Mayo

pauldry

Yup n coastal damage too