This Week's Storms - FORECAST, MODEL DISCUSSION ONLY

maquiladora

12Z GFS does not back the 12Z GME. Big difference in how they handle things.

ninebeanrows

No storm for Friday again on the GFS,

Although the storm does attempt to grow in the Atlantic but doesnt ignite, the shortwave south of Greenland is slightly less on this run but has limited affect.

No storm on GFS

irish1967

Don't think I have seen charts that different with such a short time to go. Two completely different days for us up in the NW. toss a coin ?

Deep Easterly

Latest run from EMHI HIRLAM showing similar trend for tomorrow:



Mean speeds of 24 m/s + (86km/h - 54mph - BF Severe Gale 9) along the northwest and north coasts with gusty winds over much of the country.

ninebeanrows

Ye interesting to the GME go for it abit.

Such a huge amount of disagreement.

andrew

Is it normal for different models to be showing such large differences at <24h out? Is there any way to tell which model is 'correct,' or does an intermediate case usually obtain?

maquiladora

Latest video update from the UK Met Office. Interesting.

https://www.youtube.com/watch?v=KKocsW_uBXY

gothwalk

andrew wrote: »

Is it normal for different models to be showing such large differences at <24h out? Is there any way to tell which model is 'correct,' or does an intermediate case usually obtain?

It's pretty unusual, and there's really no way to tell - both of those are in their own terms the "averaged" output of several runs. Each is "plausible" - as in, you could get there from here.

The only way to see which one is correct now is to wait and see - while keeping an eye on the 18z run this evening to see if they agree then.

This kind of divergence in the models comes up when there's a lot of energy in the whole system - some bits could cancel each other out, or they could multiply, and it's all a bit too subtle for the computer models to really make sense of.

WolfeIRE

maquiladora wrote: »

Latest video update from the UK Met Office. Interesting.

Those fax charts look like they were produced by Picasso. Is there anyway we can access those or are they just high res versions of the UKMO Fax

Look at those chilly NNE winds for Friday

ninebeanrows

Think there is some confusion here.

Tomorrow is going to be very windy and runs have intensified the storm which will particularly affect the north. There is pretty much global consensus on this.

The disparities appear at around T60 - T84hrs with regard to Friday's storm.
Where one model shows a dangerous storm approaching our southwest while the GFS shows nothing but a shortwave pushing into the channel.

SeaFields

I'd say some of the drops in pressure that some of the models are showing could lead to some coastal flooding depending on high tide times tomorrow.

maquiladora

WolfeIRE wrote: »

Those fax charts look like they were produced by Picasso. Is there anyway we can access those or are they just high res versions of the UKMO Fax

They were ensemble members, probably from a regional model. I don't think there is public access to those online.

WolfeIRE

Update from MTC
https://us.v-cdn.net/6034073/uploads/attachments/290351/184915.png

Deep Easterly

maquiladora wrote: »

Latest video update from the UK Met Office. Interesting.

https://www.youtube.com/watch?v=KKocsW_uBXY

Interesting for sure. Considering the all the possible outcomes he was showing and speaking of, he still generally puts England & Wales in the highest risk zone which suggests that he himself may be thinking that the low center will take on a more southerly course as per the latest outputs.

maquiladora

12Z UKMO is interesting...

Disagrees with the GFS, more like the GME but not as intense?

72 hours :


96 :


Pity we can't see exactly what happens in between.

M.T. Cranium

I have upgraded the wind speeds on Tuesday in the forecast ALERT (to 60-100 mph in exposed locations, 50-80 mph more generally) because of the severity of the gradient on the short-term model guidance. The alert applies mainly to Connacht, west Munster, and west Ulster although I'm sure it will be quite blustery in almost all parts of Ireland by mid-day. Also underlining the potential for near-blizzard conditions in higher parts of the realm from about 200m up, mixed horror show lower down, rain and hail to dominate only right at sea level.

The GFS maps for Friday look wrong, don't they? I have a feeling that the next few runs will see a drift back to the earlier solution but not all the way to intense superstorm (which is good). The models have probably slightly overdone the cold outflow across the North Atlantic from Greenland (this seems like a built in flaw) which may feed back into the forecast as real time data pick up on that slight difference. Also, the low in question gets off to a good start Wednesday on the GEM regional 12z and if you recall that intense low that hit the Faeroes on 25 November, that one kept getting pushed north of its original track from a similar point of origin. In fact the origins of this storm are somewhat tropical-storm in nature, doubt that there will be an invest or a TD designation but it's not entirely out of the question, and this raises some concern about how well the development will be handled.

But my main objection to the last two GFS runs would be that the phasing seems too far south for the large-scale pattern. However, will continue to hold to model consensus in the main forecast, just something to keep in mind as a plan B, a fairly strong hit on Thursday night especially for the south coast.

M.T. Cranium

Re 12z UKMO ... so it begins then ... storm 2 is rebounding on that model.

What happens in between would be a 960 mb low over Dublin at 00z, the track would appear to be north Kerry south of Shannon estuary to Thurles to Dublin then on to south Lancs and central Yorkshire. That's more or less exactly what we were talking about at some point before the weekend as a "more reasonable" evolution than that 930 mb monster in Donegal Bay that would be a most unwelcome guest.

The UKMO track would promote the risk of 80 mph (SSW) wind gusts in the south and southeast on Thursday night, and very strong westerly gusts late overnight and Friday morning country-wide. So ... the plot thickens. ECM ??

ninebeanrows

The plot thickens.

UKM being most consistent

Deep Easterly

maquiladora wrote: »

12Z UKMO is interesting...

Disagrees with the GFS, more like the GME but not as intense?

72 hours :

Pity we can't see exactly what happens in between.

One thing I have noticed about the UKMO Global model is that the general pattern always seem to look more 'smoothed' or something when compared with other model outputs with trend rather than specifics being more dwelt upon.

maquiladora

There is a significant upgrade of winds for the northwest tomorrow on the 12Z hi res NMM model since the 06Z.

Pressure down to 944mb here. It was 956mb on the 06Z...Quite a difference.

Redsunset

Interesting from Noaa for EDIT actually its for Wednesday ,looks fairly stormy.




Also yesterday they had this path for the possible big one later on in the week.

WolfeIRE

Jim Andrews of Accuweather calling 3 storms 'throughout the British Archipelago'

http://www.accuweather.com/ukie/news-story.asp?partner=accuweather&article=0

M.T. Cranium

The latest UKMO (supported by GME) evolution looks very similar to this historic storm, which from these maps does not look particularly intense, but I understand that it did a lot of serious damage in southern counties:

http://www.wetterzentrale.de/pics/archive/ra/1903/Rrea00119030226.gif

http://www.wetterzentrale.de/pics/archive/ra/1903/Rrea00119030227.gif

http://www.wetterzentrale.de/pics/archive/ra/1903/Rrea00119030228.gif

John.Icy

M.T. Cranium wrote: »

The GFS maps for Friday look wrong, don't they?

I thought this too. It all just looks strange and messy over the atlantic, more so than usual!
We'll find out soon enough.

maquiladora

WolfeIRE wrote: »

Jim Andrews of Accuweather calling 3 storms 'throughout the British Archipelago'

Anyway, had a look at the 12Z GFS ensembles and most either follow the op or develop the low on a southerly track. Only 1 or maybe 2 show something like the 12Z UKMO.

12Z ECM, you're up!

M.T. Cranium

WolfeIRE wrote: »

Jim Andrews of Accuweather calling 3 storms 'throughout the British Archipelago'

How to read that Irish market, Jim baby.

maquiladora

M.T. Cranium wrote: »

The latest UKMO (supported by GME) evolution looks very similar to this historic storm, which from these maps does not look particularly intense, but I understand that it did a lot of serious damage in southern counties:

http://www.wetterzentrale.de/pics/archive/ra/1903/Rrea00119030226.gif

http://www.wetterzentrale.de/pics/archive/ra/1903/Rrea00119030227.gif

http://www.wetterzentrale.de/pics/archive/ra/1903/Rrea00119030228.gif

There is a Met Eireann document about that MT, if you haven't already seen it.

http://www.met.ie/climate-ireland/weather-events/Feb1903_storm.pdf

Redsunset

M.T. Cranium wrote: »

The latest UKMO (supported by GME) evolution looks very similar to this historic storm, which from these maps does not look particularly intense, but I understand that it did a lot of serious damage in southern counties:



Yes indeed

http://www.met.ie/climate-ireland/weather-events/Feb1903_storm.pdf

Deep Easterly

maquiladora wrote: »

ECM, you're up!

New jar of coffee opened and an unhealthy supply of cigarettes beside me.

I'm ready!

whataboutnow

M.T. Cranium wrote: »

I have upgraded the wind speeds on Tuesday in the forecast ALERT (to 60-100 mph in exposed locations, 50-80 mph more generally) because of the severity of the gradient on the short-term model guidance. The alert applies mainly to Connacht, west Munster, and west Ulster although I'm sure it will be quite blustery in almost all parts of Ireland by mid-day. Also underlining the potential for near-blizzard conditions in higher parts of the realm from about 200m up, mixed horror show lower down, rain and hail to dominate only right at sea level.

The GFS maps for Friday look wrong, don't they? I have a feeling that the next few runs will see a drift back to the earlier solution but not all the way to intense superstorm (which is good). The models have probably slightly overdone the cold outflow across the North Atlantic from Greenland (this seems like a built in flaw) which may feed back into the forecast as real time data pick up on that slight difference. Also, the low in question gets off to a good start Wednesday on the GEM regional 12z and if you recall that intense low that hit the Faeroes on 25 November, that one kept getting pushed north of its original track from a similar point of origin. In fact the origins of this storm are somewhat tropical-storm in nature, doubt that there will be an invest or a TD designation but it's not entirely out of the question, and this raises some concern about how well the development will be handled.

But my main objection to the last two GFS runs would be that the phasing seems too far south for the large-scale pattern. However, will continue to hold to model consensus in the main forecast, just something to keep in mind as a plan B, a fairly strong hit on Thursday night especially for the south coast.

Hi,I realise u are probably getting pestered the whole time on this so I apologise in advance.How high could the wind gusts be in the corridor of Stranorlar in eastern central Donegal.Thanks