FI Charts (+T120 onwards) Autumn/Winter 2015 - see Mod Note post #1

M.T. Cranium

Two of them! c'mon GFS, surely one is enough?

maquiladora

ECM

dacogawa

maquiladora wrote: »

That low on the GFS peaks just before it reaches Ireland. +150 km/h gusts on the southwest coast. If the timing was just a bit different you'd have a truely historic storm.

Chances of it actually happening? Very slim. But not impossible.

I think with that ECM run the odds have come down a bit Maq

And it was nowhere on the last ECM, next few runs of all the models will be interesting...

Hello storm Frank

M.T. Cranium

The 500-mb panel of the GFS for that first of the two very deep lows (30th) is showing a rather difficult to accept 484 dm lobe of the polar vortex swooping down and capturing the wave. The GEM model has almost the same evolution to 29th but does not phase the upper low with the surface low and the result is a rather tame slight deepening to 970 mbs and well off the coast at that by 30th. The second low does not appear at all on the GEM, instead there is slow development off to the south in an increasingly blocked pattern.

Normally one would favour the GFS over the GEM but on occasion the Canadian model performs better. Let's hope this is one such time because that 932 mb low is basically the 1839 storm with minor variations, and the second one is almost as severe looking (it tends to develop a bit later in the approach).

Any of these severe wind storms are quite plausible given the Atlantic SST patterns and the major energy jolts that would be inserted into the jet stream by unusual synoptics over the eastern U.S.A. this next week or two. At the moment there is a significant severe weather outbreak in the Ohio valley to the Gulf of Mexico and in the dry slot behind that tomorrow, highs of 80 F are predicted in Virginia (normal is about 50 F). So it is basically this energy redeveloping over the Gulf stream then being forced into a tighter jet stream that is being partially shaped by the cold blob of ocean waters north of the Azores.

However, I am not totally buying into this yet, a strong windstorm is probably inevitable in the next 2-3 weeks in this pattern but something as strong as the GFS is showing will often downgrade. That 484 dm upper low is suspicious. The second storm then gets a late insertion of rapidly dropping 500 mb heights as well, reaching about 492 dm. (note these are heights, not thicknesses). If these two storms get served by 504 dm type support, then they will back off to today's sort of intensities or perhaps a bit stronger but not destructively so.

maquiladora

dacogawa wrote: »

I think with that ECM run the odds have come down a bit Maq

And it was nowhere on the last ECM, next few runs of all the models will be interesting...

Hello storm Frank

Potential is there for one or more stormy episodes alright. But I wouldn't believe any operational runs at this stage.

B17G

Number 7 is also interesting from the 12Z ensembles. Sends a nasty looking feature in over England, while we appear to dodge the bullet.

ninebeanrows

100mph gusts along the NW Donegal coast on the 12z EC

dacogawa

Bit of a downgrade on that run...

maquiladora

18Z again shows a deep low on the 30th, but this time the track keeps it just out to sea from the west coast.

Would still brush the west coast with 140 km/h gusts.

Hooter23

Kind of pointless looking for the exact track this far out...still interesting though that its seems so certain of a very deep depression in and around ireland in a weeks time

Gaoth Laidir

There will be a good switch in jet energy from the east Pacific to the Atlantic over the next 5 days. The exact interaction of this with low level features cannot be narrowed down at this stage but it seems likely that somewhere we will see a couple of those strong storms being progged, just exactly where is the question.

Now


Tuesday

littlemac1980

Here are the swells that Magicseaweed is predicting for he 30th.

The low pressure centre has moved slightly more North in their predictions than in yesterday's.

You can still see it in this photo though just north of the swell.

Looks pretty bad.

ninebeanrows

Probably going to skirt to the north-west on this run, but an incredibly dangerous storm progged on the 0z GFS

maquiladora

Looks like a couple of lows cross close to or right over Ireland next week in the ECM. Impossible to nail down specifics yet but the potential is there.
It looks like a deep low crosses Ireland on the UKMO between 120-144 too.
0Z GFS has a storm further in FI on New Years Day.

maquiladora

Gusts at sea off the south coast are up to 185 km/h here.

Birtles

Met Eireann flagging both of these possible events in this mornings forecast.

Potentially extremely windy or stormy weather with heavy rain developing Monday night and for a time on Tuesday.

Extremely disturbed weather will continue through the week, with some very wet and extremely windy spells expected at times, some drier brighter interludes also.

Irish Steve

maquiladora wrote: »

Gusts at sea off the south coast are up to 185 km/h here.

If I'm reading this right, and we can't see the isobars further out, this is about the best track for this event in terms of the wind over land. If it comes further North, it could be problematic, the lack of gradient so close to the centre seems to imply that it might be a relatively benign event for most of the country.

My bigger concern, along with I suspect many others, is the potential rainfall out of something like this, given how much water there already is still on the ground, and the attendant flooding risks.

maquiladora

Irish Steve wrote: »

If I'm reading this right, and we can't see the isobars further out, this is about the best track for this event in terms of the wind over land. If it comes further North, it could be problematic, the lack of gradient so close to the centre seems to imply that it might be a relatively benign event for most of the country.

My bigger concern, along with I suspect many others, is the potential rainfall out of something like this, given how much water there already is still on the ground, and the attendant flooding risks.

That is heading northeast, so it would bring strong winds over the east later on that track.

It's pointless looking at specifics seriously at this point though. Latest gfs, for example now puts the deep low south of Iceland on the 30th, we'll away from here.

sryanbruen

The BBC said we definitely are in for a storm on Monday or Tuesday

maquiladora

06Z GFS now showing no storms between now and Dec 31st. Lows are kept further west. Quite a lot of rain over the south and east on that run though.

patneve2

GFS 06Z teases in deep FI with an absolute beauty at 280 hours

maquiladora

Cold pool meets low pressure. #Snow.

Villain

Thankfully storms staying out West on latest run, yaaa for downgrades.

B17G

Juicy uppers....

Captain Snow

image posting

Rebelbrowser

I know some on here love storms but its good to look at the fi thread and see dark blues. Thats the reason most of us visit. Delighted storms around new year now looking less likely too. Sick to the gills of wind and rain.....

maquiladora

Rebelbrowser wrote: »

I know some on here love storms but its good to look at the fi thread and see dark blues. Thats the reason most of us visit. Delighted storms around new year now looking less likely too. Sick to the gills of wind and rain.....

I wouldnt say less likely yet. No storms on the 06Z GFS, but the most recent ECM and UKMO did show potential storms. We'll see what the 12Z runs show. I don't think anything will be certain for a couple of more days at least.

maquiladora

Pretty amazing 12Z GFS FI with the cold pool on one side of us and a stalled deep Atlantic low on the other side of us. Ireland right in the middle of a battleground between a snowfest and rainfest there.

Captain Snow

maquiladora wrote: »

Pretty amazing 12Z GFS FI with the cold pool on one side of us and a stalled deep Atlantic low on the other side of us. Ireland right in the middle of a battleground between a snowfest and rainfest there.

One of the greatest 12z runs so far this Winter.

I think the winter of 1947 went the same, mild start to winter then it plunged us into the freezer..........


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This is just AWESOME stuff.

maquiladora

Captain Snow wrote: »

One of the greatest 12z runs so far this Winter.

I think the winter of 1947 went the same, mild start to winter then it plunged us into the freezer..........


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This is just AWESOME stuff.

Yep pretty cool to see the different airmasses colliding like that. But like the big storms shown yesterday, the GFS FI will no doubt change again tomorrow...

sryanbruen

I can't remember there being a Tuesday, December 29th without a storm or heavy rain!

1998 - flooding in Blackwater
2009 - falls up to 40mm in the south
2015 - now looking like a storm will come on this day

Stealthfins

Captain Snow wrote:

I think the winter of 1947 went the same, mild start to winter then it plunged us into the freezer..........

I said that a few times here over the past week.
I think were in for a hard January.
Get the logs coal and turf stacked up ðŸ˜

Elmer Blooker

Captain Snow wrote: »

I think the winter of 1947 went the same, mild start to winter then it plunged us into the freezer..........

..... a meteorological myth, there was no mild start to that winter as Europe froze in December.

Stealthfins

Elmer Blooker wrote:

..... a meteorological myth, there was no mild start to that winter as Europe froze in December.

Says who ?

maquiladora

Another near miss on the 18Z GFS.

maquiladora

B17G wrote: »

The lovely snowmageddon charts from earlier in the day have disappeared off the latest run. Oh the tease that is FI.....:(.

Oh no they haven't! #snowfest

B17G

Ah, sorry Maq. After deleting that post in a fit of unhappiness, if anybodys confused looking for the original!!

I shall try to stay optimistic! There's a -12 upper nibbling at the SE coast at +300.

maquiladora

18Z GFS FI goes into Christmas eye candy land, and by the end of the run....

teddybones

maquiladora wrote: »

18Z GFS FI goes into Christmas eye candy land, and by the end of the run....

Christmas present! Ta! I will take hope over nowt!

Elmer Blooker

Stealthfins wrote: »

Says who ?

Read reports from December 1946 here.

THE GREAT FREEZE.
Impact On Western Europe.
LONDON, Dec. 22.-England and Western Europe are in-the
grip of the most intense cold this winter. The Vistula River is
frozen over, the temperature at Prague is 28 degrees below freezing
point, the Rhine for the first time since 1929 is ice-bound at three
points in the French occupational zone, and in London yesterday
the shortest day of the year was also' the coldest.

http://trove.nla.gov.au/ndp/del/article/46250351

squarecircles

Latest from bbc weather saying next week is looking increasingly stormy.

RobertKK

Elmer Blooker wrote: »

Read reports from December 1946 here.


http://trove.nla.gov.au/ndp/del/article/46250351

Yeah, my father who was 19 years old at that time, said it was freezing for weeks before the snow came, there was an easterly wind and knowing nothing good comes the east in winter - this was before they had electricity. He spent the time collecting wood everyday and then the snow came...

maquiladora

Not to derail this thread further, but the winter of 46/47 did feature cold spells in Ireland in December. However it was not until the later half of January that the "real" cold began.

The first half of January 47 was mild, wet and windy in Ireland. Dublin Airport recorded double digit temperatures up until the middle of the month. The famous relentless severe cold spell began around Jan 23rd in Ireland.

Anyway...back to that charts that won't happen!

Captain Snow

This is why we love FI Charts


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Merry Christmas

maquiladora

0Z GFS shows a direct hit. 130-140 km/h gusts inland right over the country.



0Z UKMO evolution looks similar. The tight gradient would also probably pass up over Ireland here a few hours before this.



Happy Christmas!

maquiladora

0Z ECM looks similar at 120 hours. Strong winds would have over or very close to Ireland just before this.



And then it shows a beast approaching us at 168 hours. Isobars packed severely tight.

Gaoth Laidir

Here are the gaps filled in on the ECMWF. I think this is the crescendo of the Atlantic before it retires for January.

maquiladora

06Z GFS again showing very stormy conditions Tuesday night/Wednesday morning.
Still several days away so not nailed down yet. But potential is there for something quite significant.

B17G

Variant 6 on the latest ensembles generates a low of 915mb but keeps the worst of the winds out to sea.

Gaoth Laidir

Euro ensembles show strong height anomalies over Scandinavia for a while in early Jan but not hanging around for long.