Model output discussion 14/04/18

[damianslaw]

A change in conditions is upon us, still warm, very warm for some but more of an unsettled theme thanks to an injection of a more unstable airstream caused not least by a pulse of warmer uppers from the continent and a slack airstream - ripe conditions for localised torrential and long lasting thunderstorms. 

Northern parts look like escaping any unsettled weather for the time being.

The synoptics of the past 2 weeks and for the foreseeable are the exact type that have brought vintage summer periods in the past - alas we are still in May, and it would be a tall order to see them sustain themselves through the summer as a whole, last time I will say it, but now is the time of year when we are most likely to see a sustained break from the atlantic, so nothing surprising about how things have panned out recently, its just that recent May's have been devoid of settled sustained weather.

May 2018 will go down as the type of perfect month for me. Once again - love May, it is the best month.

[Cheshire Freeze]

GFS 0z takes a steady slide into a potentially very wet scenario (albeit quite warm at times)

It lets the Atlantic in a bit more definitively on this run towards day 10...

....and carries on huffing and puffing out to the end of the run. Though continental HP is never very far away-

All things considered, I'm still happy with my thoughts I've had since early April RE spring into summer. Followed the script chapter and verse thus far.

I'm just happy that it looks as though we may get to see some more in the way of actually interesting weather over the next 10 days or so!

[Guest]

Yes I mentioned last night that little upper cold pool could be a nuisance and gfs demonstrates this perfectly. One thing that we really don’t want to happen is for that to develop and then become stuck the over the UK.

[Evening thunder]

UKMO and especially ECM are a very big last minute downgrade down here, gone is the 10C+ uppers as early as t+72, and E/NE drift, and storm potential. Just more 'normal' conditions instead. Why can't these charts be right for once

We might not even get a very warm day here now depending on cloud etc,, or only one.. and only one shot at any thunderstorms on Saturday night... Probably quite an unremarkable spell while even most of Scandinavia, even up to Lapland at times find it far easier to get higher temps than us (even under similar uppers). If it seems too good for this country, it probably bloody well is!

Edited May 25, 2018 by Evening thunder

[Guest]

11 minutes ago, Evening thunder said:

UKMO and especially ECM are a very big last minute downgrade down here, gone is the 10C+ uppers as early as t+72, and E/NE drift, and storm potential. Just more 'normal' conditions instead. Why can't these charts be right for once

We might not even get a very warm day here now depending on cloud etc,, or only one.. and only one shot at any thunderstorms on Saturday night... Probably quite an unremarkable spell while even most of Scandinavia, even up to Lapland at times find it far easier to get higher temps than us (even under similar uppers). If it seems too good for this country, it probably bloody well is!

Yes short term ECm isn’t what we wanted to see and removes the warm air very quickly although it is much cooler then gfs mean. 

[mb018538]

Surprising ecm for sure. We’ve had warm conditions progged all week, for them to vanish at 3 days notice would be a surprise! All eyes on the tv forecasts.

[mb018538]

Just having a more detailed scan through the output.....ECM is slightly on it's own, all other models keep the warm air around on Monday and into next week. Perhaps a bit of an outlier - the TV forecasts haven't changed overnight either, so they are obviously still confident somewhere will see 28c. Looking pretty unsettled by midweek though, flabby low pressure and warm unstable air around could result in a lot of hefty showers. Pinning these down impossible at this range. In the longer term it's hard to know where we move from here. I'd say the form horse would be a slow transition to something more unsettled, but this open to debate.

[shaky]

Was pretty darn shocked to see the ecm and ukmo this morning!!didnt expect pressure to be that low and as early as 3 days away!!gfs on the other hand looks gorgeous!!high pressure all the way into next week with hot and humid air covering most of the uk!!lets hope for a backtrack from the ecm and  ukmo 12z!!

[northwestsnow]

Very nice 00z runs and GFS 6z now much better , staying warm all through the weekend and next week, with some thundery activity mainly in the south.

 

[Scorcher]

6 hours ago, CreweCold said:

GFS 0z takes a steady slide into a potentially very wet scenario (albeit quite warm at times)

It lets the Atlantic in a bit more definitively on this run towards day 10...

....and carries on huffing and puffing out to the end of the run. Though continental HP is never very far away-

All things considered, I'm still happy with my thoughts I've had since early April RE spring into summer. Followed the script chapter and verse thus far.

I'm just happy that it looks as though we may get to see some more in the way of actually interesting weather over the next 10 days or so!

I can't see this at all, there is very little prospect of the Atlantic roaring back any time soon in my opinion. If there's any rain it's likely to be in the sort of setup we have now- the Atlantic is not really involved in producing this rain and is still quiet. 

That seemed to be a rogue run from the GFS this morning- the 06z has backtracked on it now and looks fairly quiet again.

 

 

[Frosty.]

Reading some of the posts so far today I thought the warmer spell had been cancelled but nope, just looked at the models and it's very much alive and well with a predominantly summery period ahead of us...nationwide!

[mb018538]

Not surprisingly the excellent 6z gfs run was a warm outlier. I’d be very surprised if we get that amount of high pressure returning. More favoured is the ‘dogs dinner’ outlook of slack pressure patterns and a weak jet stream meaning nothing moves very quickly.

[summer blizzard]

Trades strengthened over the Pacific around the 15th-20th May so allowing for a 20 day lag i can see the support for a breakdown complete in the first third of June so modelling is not overly shocking to me. 

MJO wave setting up the Indian Ocean right now (bad for now since the combo enhances the Pacific gradient) which may move west into early/mid June. That may suggest that eyes should be on late June for a pattern switch back to hot (i say this as somebody who wants a cool July/August).

 

[Frosty.]

Despite some doom and gloom posts earlier today, I don't see any downgrades on the latest output, it looks like becoming very warm with a lot of dry, sunny weather and scattered thunderstorms with temps into the mid to upper 20's celsius, warmest further south where it also looks increasingly humid..the latest MO update is very summery too! 

[northwestsnow]

28 minutes ago, Frosty. said:

Despite some doom and gloom posts earlier today, I don't see any downgrades on the latest output, it looks like becoming very warm with a lot of dry, sunny weather and scattered thunderstorms with temps into the mid to upper 20's celsius, warmest further south where it also looks increasingly humid..the latest MO update is very summery too! 

Yes Karl, its a brill outlook for warm weather fans, and of interest to add to summer blizzards excellent post above the metoffice now hinting at any unsettled weatheer towards mid june being rather shortlived, somrthing to keep an eye on.

Edited May 25, 2018 by northwestsnow

[Jonathan Rhodri Roberts]

IMO, they are terrible model runs today for here in South Wales as it looks like we're getting stuck with a prolonged period of very warm & humid days and nights with a risk of thunderstorms every day for Whitsun week as the low doesn't really move anywhere. I can't stand heat with very high humidity as it plays absolutely havoc with my asthma, luckily I live near the coast so will probably be going in the car to the beach each day to feel the cool sea breeze and hopefully lower humidity too  unusual I know but I'm now actually hoping for a swift return to the west to east flow in early June as hinted by some models to cut off this continental flow with all those thundery lows/ troughs

Edited May 25, 2018 by Jonathan Rhodri Roberts

[Mike Poole]

A variety of posts here today not all of which I agree with. Depends what people's preferences are I guess, but I can't see wall to wall sunshine, nor can I see an Atlantic revival in the output this morning.  It all looks a bit of a mess with the main jet well north, leaving isolated lows and high pressures to jostle for position.  Likely weather warm, some sun, humid, and potential for thunderstorms which may be slow moving, and torrential downpours.  Should give us weather lovers something to talk about!

Edited May 25, 2018 by Mike Poole

[Frosty.]

2 minutes ago, Mike Poole said:

 Likely weather warm, some sun, humid, and potential for thunderstorms which may be slow moving, and torrential downpours.  Should give us weather lovers something to talk about!

It's what the models have been showing for days and I'm looking forward to it!

[Derecho]

1 hour ago, northwestsnow said:

Yes Karl, its a brill outlook for warm weather fans, and of interest to add to summer blizzards excellent post above the metoffice now hinting at any unsettled weatheer towards mid june being rather shortlived, somrthing to keep an eye on.

The 06z certainly kept the heat going for a long time, what a period of weather this could be shaping up to be.

One word of caution however is a tropical storm / hurricane forecast to hit the US in a few days, when that enters the North Atlantic again it may provide some knock-on effects downstream.

Fingers crossed for some storms down here though. Northern France seems to be quite thundery at the moment.

[Frosty.]

25 minutes ago, Quicksilver1989 said:

The 06z certainly kept the heat going for a long time, what a period of weather this could be shaping up to be.

 

The GEFS 6z mean looks really summery too, high pressure / ridging and warmth well into early june..models continue to look great and backed up by Exeter too..looking forward to the much warmer weather following today's rain and cool temps!..bring on the warmth / heat and sunshine..and storms!

Edited May 25, 2018 by Frosty.

[northwestsnow]

Lovely GFS12Z , not so sure what to make of ukmo 144- looks quite slack , probs be warm although quite thundery ?

[Mike Poole]

Well here's the business end of the GFS 12z, first jet stream at T192, well north!

Which leaves much space for moderate highs and lows to compete for position over the UK, here's the evolution on this run:

Warm . The north more favoured for settled weather, I think.  The south could have the most potential for storms, interesting times. Pick the bones out of that, could be a lot going on in the next week or so .

Edited May 25, 2018 by Mike Poole

[Frosty.]

17 minutes ago, northwestsnow said:

Lovely GFS12Z 

Indeed, the Gfs 12z shows temperatures well into the low / mid 20's celsius from tomorrow and right through next week in many parts of the uk, actually the s / se is into the low 80's f on most days during the week ahead which would be feeling very warm / hot. There's a good deal of dry and sunny weather across the uk too as well as some thunderstorms, the storms mainly further south..really summery set-up.

Edited May 25, 2018 by Frosty.

[Evening thunder]

 

4 hours ago, Frosty. said:

Reading some of the posts so far today I thought the warmer spell had been cancelled but nope, just looked at the models and it's very much alive and well with a predominantly summery period ahead of us...nationwide!

For those that don't understand some posts like mine this morning, here's the ECM 00z derived forecast for my location:

Those are 1pm temps so maxima could be a degree or two higher.. but even so, it would be very disappointing if something that looked very good ended up not being much better than average really.

Hopefully it was a bit of a rouge run.. but even the Met Office's own forecast isn't much better for me, slightly warmer than average, a fair bit of cloud.

Of course the change on the ECM 00z probably makes less of a difference further north/east, but it makes all the difference down here.

Edited May 25, 2018 by Evening thunder

[Mike Poole]

Similarly for GEM, here's the jet stream at T192 for comparison with GFS above:

And here's the evolution through to T240:

Backs up the view of on average more settled sunny conditions to the north, thundery further south - I wonder if the jet is a bit too far north for really hot weather in the south of the country.  Interested in the ECM tonight.  Interesting summer weather .

Edited May 25, 2018 by Mike Poole