Model Output Discussion - heading into April

[Methuselah]

Aye. And the GFS 12Z is shaping up nicely by Day 10:

    

[mb018538]

UKMO is fantastic again by 144 - turning very warm again. The 168 chart (next Sunday) would likely see temps approaching the mid 20s again.

[Zak M]

The GFS 12z on day 12 is okay;

   

[Methuselah]

The building blocks should be in-place before the start of June...

   

[Don]

20 minutes ago, General Cluster said:

The building blocks should be in-place before the start of June...

   

Flaming June this year?  Longer range models seem to be hinting that could be the case.

[Mark wheeler]

The mighty Navgem Run earlier today seemed to have a nice area of high pressure building in nicely . 

[Methuselah]

The GFS 12Z operational run lies almost slap bang in the middle of the temperature ensembles:

    

But never looks particularly warm.

[Mike Poole]

Another gem of a run from the GEM, that's 3 on the bounce now:

 

And ECM looking good at T168:

These two models have been consistent for the last three runs, so hope it happens now, some sunshine will help in mourning the death of our economy, maybe.

Edit: ECM T240:

Edited May 10, 2020 by Mike Poole

[mb018538]

Great ecm tonight once more. Turning much, much warmer. Bring it on!

[Frosty.]

This evening’s ECM 12z operational is poetry in motion, turns into a superb run, especially the further south you are where it becomes much warmer again..a very good follow up to the 0z..great continuity actually!

[MATTWOLVES 3]

No complaints from me with the ECM run I think we all needed a pick me up after the BJ announcement, and the weather at least looks like delevering on its promises.. Lovely jubilee.. Hopefully you can all get to enjoy it.. Keep safe. 

Edit.. Karl beat me to it...

Edited May 10, 2020 by Mattwolves

[Zak M]

Good evening all.

After this weeks below-average weather we could be in for a treat next week. Most models indicate a high developing over the British Isles along with some very warm weather. Let's see what the models are up to:

First off, the classic GFS. The 12z run is okay on day 10. The next couple of days after day 10 look alright with temperatures into the low twenties in the SE but from that day onwards a low will start to budge in from the NW and might deliver some rain to the British Isles, so not the most pleasant.

      

The GFS ens are okay too. Once again though it is just a mess from day 10 onwards, where most models show the spell of nice weather. The control is the only one that stands out.

   

Next up, is the UKMO. Quite a nice 12z run actually. It shows a high settling on top of the UK from day 5, so much earlier than most other models. Temperature-wise, it doesn't look too good in the north, with the 0c 850hpa isotherm being reached there. In the south, it shows 4-8c 850hpa isotherms so it will be warmer in the south, with the high teens likely in England and Wales, with the odd 20c possible somewhere in the far SE/London area. The UKMO only goes up to +144 so it is a bit uncertain about what will happen after that.

      

Following on from the UKMO is the ECM. The 12z is a very good run and shows a high pinned onto the UK from day 6 onwards. Looking at the 850hpa temperatures on the same day, there is still a 0c 850hpa isotherm in northern areas and the 4c 850hpa isotherm in southern areas so it won't be too warm just yet. However, day 9 is when the ECM shows the warmth and it even starts to become a bit more widespread too. It has the 8c+ 850hpa isotherm in southern areas, meaning that daytime temperatures in these areas should range from around 17-23c. The ECM still has the HP pinned on top of the UK from day 6 up to day 10!

      

And finally, the best one I saved until last, the GEM. The 12z run of this model is an absolute stonker. A high gradually sets in to the UK on day 7, and is still stalling there on day 10 (the GEM only goes up to +240), meaning some very fine and settled weather. The main reason why I think this run has been amazing tonight is because it shows much higher temperatures to come on these days than most of the other models. It shows 27c or perhaps even higher in some places possible in NE Wales on day 9!! Looking at the 850hpa temperatures also, it shows the 10c 850hpa isotherm covering most of the UK, with perhaps the odd 12c 850hpa isotherm being reached in the far SE!! Currently it is the only model that shows temperatures this high though, so whether it will come off is questionable. 

      

      

Obviously it is still quite a long way off, so some things could be subject to change. If we still have some models showing this weather in 5 days time, then we really could have a remarkable spell of weather coming up.

Also, Boris Johnson has announced that we can relax outside now a bit more than usual without being fined. However, you are planning to go outside, just remember to keep your distance with everyone.

Take care all! Hope you all enjoyed your weekend

[Mike Poole]

22 hours ago, Singularity said:

It’s interesting to see the potential for the Atlantic trough to dictate the direction of travel from a position S of Greenland again later next week.

Reason being, that’s what’s encouraged by one of the only two driving forces pointing toward a warm and dry type summer for 2020 - the N Atlantic SST anomaly pattern.

Research has shown that what we have in May tends to persist through the summer via positive feedbacks involving the atmosphere. Anomalous warmth east of Newfoundland enhances the temp gradient S of Greenland, encouraging cyclogenesis there I.e. a +NAO.

 

The other factor isn’t actually with us yet - a negative Indian Ocean Dipole (as forecast by BOM). Analogues for this are anomalously settled for S UK, most notably in Jul-Aug. Not so good in the north mind - a lot of changeable westerlies. Heat tending to build up from the south at times, though.

Just want to comment further on the positive feedback SST issue, that you raise, as an explainer. And it is why I think this summer will be hot and dry for the south and probably midlands.  

Here's the latest SST anomaly:

These things change slowly, so it isn't wrong to compare with the ECM T240 chart:

You can see that for the sea relatively speaking, the warmer areas are by and large going to get warmer under high pressure with heat from the sun and the colder areas are going to get colder under depressions, and cloud.  

This is something about the weather that I find really interesting, how patterns can become self-reinforcing.  And it can happen in winter as well, of course, snow cover reflecting sunlight and reinforcing cold.  Anyway, just wanted to share that.

I'm not making any comment about the other part of @Singularity post, about the Indian Ocean Dipole, just typing the name of it brings me out in hives after this winter!

Be safe everyone!

Mike

Edited May 10, 2020 by Mike Poole

[Singularity]

Nice one, MP .

 

   
  

It's really starting to fascinate me how often we see GFS being the 'odd one out' that doesn't want to party with the others in the mid-range. Most comparable to it is ICON but that still doesn't have such high heights due north of the UK with an uninterrupted 'arm' (or... peculiar hair-do?) of high pressure reaching up to the east of Greenland.

So far, I can't recall GFS winning out in this situation. Would be something to see, though - so much electronic egg on so many digital faces.

[damianslaw]

3 hours ago, Don said:

Flaming June this year?  Longer range models seem to be hinting that could be the case.

Mmm not sure where the building blocks are, westerly airstream jet aligned on a NW-SE trajectory, heights to the south, standard fayre.

[shaky]

Fantastic fantastic ecm mean this evening!!strong heights across the whole of the uk from start to finish!!looks even better than the op between 168 and 240 hours with the high a bit further north!!

[Allseasons-Si]

Evening all and fantastic post's as usual^

long-ish post coming up as there is more fine weather on the way

@Singularity i was just about to post all the 144hr charts as they all show the Azures ridge pumping up from the SW and i just hope that the gfs is playing catch-up AGAIN or will it be right!

i will post them anyway...

to be honest,there isn't that much difference in the six,i think what is wrong with the gfs is that there are more heights to the north forcing that trough further south through Scandinavia

What i very muchy do like is the day ten means from both the ecm and gefs,both show ridging into the UK but the orientation/placement will be crucial as to how the temps will respond  

ecm/gefs ens + gefs pressure chart shows a steady incline to warm'er temps and mainly dry up to day ten then pressure falls and becomes more unsettled but this is a long way off,so plenty of usable weather to "again" get out and enjoy

cpc 6-10/8-14 day 500mb anomaly charts in the same ballpark as the means above and this fine spell could get extended looking at those charts

a cool day today and i was mostly indoors doin stuff as you do but i cannot wait to get back out in the fine weather again,doesn't it lift your moral and spirits in you when the sun is shining,come on  

and finally a last word or three

KEEP BUSY

KEEP SAFE 

KEEP CALM

laters

 

 

 

 

Edited May 10, 2020 by Allseasons-si
typo

[MATTWOLVES 3]

Fantastic ECM mean is the only way I can describe it... High pressure in strong control right out to day 10,and most likely beyond.. 

Edited May 10, 2020 by Mattwolves

[Allseasons-Si]

First out of the blocks is the ICON and an upgrade in terms of pressure placement and warmer temps

18z 120 v's 12z 126.

[Mike Poole]

4 minutes ago, Allseasons-si said:

First out of the blocks is the ICON and an upgrade in terms of pressure placement and warmer temps

18z 120 v's 12z 126.

Oooooh! Posting the 18z ICON, Si? That's not normal at this time of year!  Does this mean we are on the cusp of something?  I think so, anyway!

[Allseasons-Si]

And just to add to my previous post's above

these are the london and De-built(dutch) ecm ens,now look at that diurnal range there(warm days and cool nights),this signals high pressure

 

this is what i look for for fine weather.

[Allseasons-Si]

This is better from the 18z

and falls in line with the rest,trough into Scandi almost non existent.

[damianslaw]

Not sure why such over excitement from everyone chart mean wise, perhaps the impending cool spell, but we've had better means in recent weeks for sustained dry settled weather, it's hardly been unsettled. The azores high rising through but the Atlantic ready to pounce, good for the south east perhaps. Need a touch of realism today.

Edited May 10, 2020 by damianslaw

[Mike Poole]

2 minutes ago, damianslaw said:

Not sure why such over excitement from everyone chart mean wise, perhaps the impending cool spell, but we've had better means in recent weeks for sustained dry settled weather, it's hardly been unsettled. The azores high rising through but the Atlantic ready to pounce, good for the south east perhaps. Need a touch of realism today.

I don't understand some of your recent posts, the Atlantic is definitely not going to pounce, any time soon.  GFS 18z at T210:

Settled and warm for most of the country I would suggest?

[damianslaw]

10 minutes ago, Mike Poole said:

I don't understand some of your recent posts, the Atlantic is definitely not going to pounce, any time soon.  GFS 18z at T210:

Settled and warm for most of the country I would suggest?

Direction of travel eventual Atlantic driven pattern, look at jetstream profile forecasts beyond 240hrs, yes 10 dats off but show jet taking a more direct flow to the UK on a westerly trajectory, you can see the stirrings in chart above SW flow incoming. Until then lots of fine settled weather. Not saying it will mark the start of a lengthy unsettled spell, but more so after 2 months of little Atlantic weather there are indications it will make a comeback before month is out. Someone also mentioned sst profiles favour rapid cyclogensis south of Greenland through summer, ushering in more unsettled weather to the north, less so in the south. Chart above echoes this, deep low formation in that vicinity of Atlantic.

Edited May 10, 2020 by damianslaw