Storm Barra: December 7/8th 2021 Technical Discussion Only

SleetAndSnow · 06-12-2021 7:29pm #1

Since the other thread is currently burying a lot of the graphs posted, I decided to make a technical thread for this storm.

Current weather warnings:

Status Red - Wind warning for Cork, Kerry

Met Éireann Weather Warning
Storm Barra: Southwesterly winds later veering northwesterly will reach mean speeds in excess of 80 km/h with severe or damaging gusts in excess of 130km/h. Due to a combination of high waves, storm surge and high tide, coastal flooding is expected. Disruption to power and travel are likely.
Valid: 06:00 Tuesday 07/12/2021 to 21:00 Tuesday 07/12/2021
Issued: 13:47 Monday 06/12/2021

Status Red - Wind warning for Clare

Met Éireann Weather Warning
Storm Barra: Northwesterly winds will reach mean speeds in excess of 80 km/h with severe or damaging gusts in excess of 130km/h. Due to a combination of high waves, storm surge and high tide, coastal flooding is expected. Disruption to power and travel are likely.
Valid: 16:00 Tuesday 07/12/2021 to 01:00 Wednesday 08/12/2021
Issued: 16:21 Monday 06/12/2021

Status Orange - Wind warning for Clare, Cork, Kerry, Limerick, Waterford, Galway, Mayo, Wexford

Met Éireann Weather Warning
Storm Barra: Southeasterly winds, later veering northwesterly will reach mean speeds of 65 to 80 km/h with severe or damaging gusts of 100 to 130 km/h, with localised stronger winds likely, with severe gusts on coasts. Due to a combination of high waves, storm surge and high tide, coastal flooding is expected. Disruption to power and travel are likely.
Valid: 06:00 Tuesday 07/12/2021 to 06:00 Wednesday 08/12/2021
Issued: 13:47 Monday 06/12/2021

Status Orange - Wind warning for Dublin, Louth, Wicklow, East Meath

Met Éireann Weather Warning
Storm Barra: Southeasterly winds will reach mean speeds of 65 to 80 km/h with severe or damaging gusts of 100 to 130 km/h, with localised stronger winds likely. Due to a combination of high waves, storm surge and high tide, coastal flooding is expected. Disruption to power and travel are likely.
Valid: 08:00 Tuesday 07/12/2021 to 13:00 Tuesday 07/12/2021
Issued: 13:47 Monday 06/12/2021

Status Yellow - Wind and rain warning for Ireland

Met Éireann Weather Warning
Storm Barra will bring widespread mean speeds of 50 to 65 km/h and gusts of 90 to 110 km/h with localised stronger winds likely. Heavy rain will also bring risks of surface flooding and, due to a combination of high waves, storm surge and high tide, coastal flooding is expected. Disruption to power and travel are likely.
Valid: 02:00 Tuesday 07/12/2021 to 18:00 Wednesday 08/12/2021
Issued: 13:47 Monday 06/12/2021

No chat in this thread please!

sdanseo · 06-12-2021 7:36pm

Vanilla doing odd things, duplicated my post then removed it as I tried to delete.

ECM 12Z showing the centre over Galway at 1400Z - 959mb.

Assume the snow depth chart can be consigned to the heap? Temps simply don't appear to support a blizzard (yet).

almostthere12 · 06-12-2021 7:40pm

https://www.boards.ie/discussion/comment/118279726#Comment_118279726

That was going to be my exact question........looks like uppers won't even reach - 4 until Wednesday and then it's over the southern half of the country and not the northwest

Gizit · 06-12-2021 7:43pm

Has anyone got a link for a pressure chart in the North Atlantic? I've looked on Meteociel and can't find one that covers the area of interest

sdanseo · 06-12-2021 7:48pm

HIRLAM, ICON and ARPEGE all showing very high tail-end winds for Mayo, Sligo and Donegal into Wednesday. Surely they will need upgrading to Orange at least.

Akrasia · 06-12-2021 8:26pm

I was surprised met Eireann ended the red alert for Clare at 1am, some of the strongest winds on some of the models were after 1am Wednesday morning

Gaoth Laidir · 06-12-2021 8:42pm

18Z analysis and latest water vapour image, showing nice dryslot to the rear of the cold front.

These are the 6-hourly pressures up to 18Z. A decent fall of 18 hPa in the last 6 hours. At 50N, the figure for rapid (or "bomb") cyclogenesis (1 Bergeron) is 21.2 hPa/24 hours.

Time | hPa
00Z | 1019
06Z | 1016
12Z | 1009
18Z | 992

Meteorite58 · 06-12-2021 9:03pm

Latest ECM, GFS and ARPEGE and GEM all quite close in track and timing, UKMO a bit lower and ICON lower again, ICON similar run to the 15Z but would side with the other bunch tracking in over or close to Galway at this stage. A good waypoint tomorrow to check who did well !

Meteorite58 · 06-12-2021 9:21pm

Re the ICON chart above, checking closer and it would seem that it arrives slower than the rest and in turns delays the strongest second wave of winds and continues strong winds well into Weds , UKMO also showing a large swathe of strong winds over the country on Weds, ECM keeping the strongest winds on Weds to around Mayo and Sligo. Warnings could keep going well into Weds especially on the coasts , will slow the electricity repairs especially in coastal counties that were effected.

pad199207 · 06-12-2021 9:25pm

A good push onto the east coast tomorrow morning

Meteorite58 · 06-12-2021 9:36pm

ARPEGE might be a good average across the models at this stage, certainly some stronger but not a bad representation of what to expect atm . No doubt there could be a few surprises along the way as in some places getting unexpectedly higher winds. The combined effect of the squally rain will be notable Id say. Not expecting power to last long into tomorrow evening here in Kerry, if I get to 18.00 or 19.00 I will be doing well I'd say.

Quite a few sferics showing up today would expect the same again tomorrow around the coastal areas especially.

Meteorite58 · 06-12-2021 9:52pm

On its way!!

GFS rolling out and it looks nasty.

Sammy2012 · 06-12-2021 9:59pm

Any rainfall charts for tomorrow? Or is the main threat of flooding from coastal flooding?

eskimocat · 06-12-2021 9:59pm

Howdy all...waves excitedly from behind screen! the storm brings some of us old weather forum fans back to their roots again!

I just wanted to mention one of my favourite storm watching websites for these kinda of occasions. Eart Not affliated with it in anyway....but its really interesting to see the shape that this storm is developing out there.... I'm not sure how accurate etc... the info on it is, but some may enjoy it!

https://earth.nullschool.net/#current/wind/surface/level/orthographic=-11.78,52.03,2714/loc=-21.817,50.006

pad199207 · 06-12-2021 10:03pm

Cluedo Monopoly · 06-12-2021 10:08pm

If possible, could the experts please leave a link for their images. I will love to learn more.

pad199207 · 06-12-2021 10:18pm

Lightning strikes in storm barra

United road · 06-12-2021 10:22pm

https://www.boards.ie/discussion/comment/118280741#Comment_118280741

Sorry Pad

may i ask you, what do they mean when they say - 1 of 3 next 96hrs??

dacogawa · 06-12-2021 10:36pm

Sat View just under an hour ago.

Chris_5339762 · 06-12-2021 10:43pm

Will be interesting to see where it ends up - technically I always find these storms are always slightly earlier and slightly further north than any of the model runs.

Meteorite58 · 06-12-2021 10:48pm

ARPEGE 18Z is rolling out and I don't say this lightly but looking like an upgrade again, strong winds well into Weds, one hell of a long event, look at how tight those isobars are. Cant remember facing into a storm of this strength and duration to be honest. I think we are going to see a lot of power outages and damage from this one especially in the Red warning counties and Kerry looks like it is going to be battered altogether.

History Queen · 06-12-2021 11:00pm

Are we likely to see more areas upgraded to orange or red do you think?

https://www.boards.ie/discussion/comment/118281064#Comment_118281064

⁷

Meteorite58 · 06-12-2021 11:09pm

https://www.boards.ie/discussion/comment/118281132#Comment_118281132

Galway looking like a very high Orange later Tuesday, wouldn't take much to push it into Red I think.

Sligo Could go Orange for a time early Weds.

Looks very windy in central counties as well during the early hours of Weds morning, would need to keep an eye on this to see if the models show this to increase, high Yellow at least for a time.

adocholiday · 06-12-2021 11:12pm

Joanna was on Claire Byrne and said that given current guideance they didn't foresee a change in the warning levels, but that coincided with Meteorite's post with the ARPEGE output so it might change yet.

Oscar Bravo · 06-12-2021 11:14pm

11pm TAF's

Cork Max gusts :65knots

Shannon :65 knots

Dublin 55 Knots

Knock 45 knots (Down to just 10 knots as the low passes directly over in the afternoon)

[Deleted User] · 06-12-2021 11:17pm

https://www.boards.ie/discussion/comment/118281064#Comment_118281064

I have a barometer mounted on gable end of shed....shes been dropping like at stone since daybreak.....32hpa drop in 17hrs....... this lady is going to be frisky as hell for Cork & Kerry from early hours onwards. You're right re power outages.....I set up a new generator system earlier on in the year.....enough power for fridge freezer,1 kettle & charging phone......was hoping she'd never get tested but I reckon she'll be called into action over the next 24hrs. 2x chainsaws primed & ready to go, everything that 'could' possibly move has been stowed away, phone charged 100%, plenty of fuel for the stove brought in. The 2doggies are holed up in front of stove. I'm NORTH Cork btw....... keep safe everyone....i ain't looking forward to the next 24/36 hrs....lets hope for the best.