Model Output Discussion - Autumn arrives

[mb018538]

Now that’s the type of summer chart I love to see….Azores high steaming in on day 11 of the 12z GFS op.

[bluearmy]

The gem has variation on a theme for later next week ……the gem sometimes grabs the initiative …..

[Mark wheeler]

Liking the trends this evening. Fantastic post @Captain Shortwave I enjoyed that as always .

[mb018538]

Wouldn’t like to make too many predictions for later next week going on tonight’s output….another disrupting trough scenario potentially unfolding, making gfs/ecm/gem all very different by day 10!

[tight isobar]

1 hour ago, mb018538 said:

Wouldn’t like to make too many predictions for later next week going on tonight’s output….another disrupting trough scenario potentially unfolding, making gfs/ecm/gem all very different by day 10!

Variations- via the outs... But a definite fading- And more west based trough already,.. And The Azores looking more iron fisted each suite!.. the models over the weekend WILL be telling, As July beckons. The big heat month for my own estimation !!

Edited June 23, 2022 by tight isobar

[Mark wheeler]

And its about time we have had a special from the mighty mighty Navgem . 

[Allseasons-Si]

20 minutes ago, Mark wheeler said:

And its about time we have had a special from the mighty mighty Navgem . 

And the heat looks like it's going to pinch the UK by it's backside

3 hours ago, bluearmy said:

The gem has variation on a theme for later next week ……the gem sometimes grabs the initiative …..

and hopefully the ignition to come with it too,...cracking run from the gem

 

Edited June 23, 2022 by Allseasons-si

[MP-R]

9 minutes ago, Allseasons-si said:

And the heat looks like it's going to pinch the UK by it's backside

and hopefully the ignition to come with it too,...cracking run from the gem

 

Some thundery interest for sure on that run, but not helpful for my needing of a dry and sunny day on the 2nd lol. Hoping for a less bullish Biscay low and a longer period of higher pressure between lows. Nice to see alternatives to Atlantic dross though.

[tight isobar]

Decrease.. by declassification!! Top polar organisations.. And not an Azores feature, But a whole expansion of the Atlantic sheet!-classic two way absorbing of an overall minimal depleating trough format!.. that has only “one way “ fruition, a tsunami of full injection equatorial based Air sourcing. Some heat computer Synoptics not to far away imo , for too Europe as a whole .. we’ll await deciphering!. But as again July is primmed for summer loving types!!

Edited June 23, 2022 by tight isobar

[clark3r]

Gfs this morning shows a very warm Wednesday next week maybe touching 30, and hot Thursday 32 possible, looses the heat FI on this run, interesting to see what other models show this morning 

[bluearmy]

13 hours ago, bluearmy said:

The gem has variation on a theme for later next week ……the gem sometimes grabs the initiative …..

It might not have been so outlandish 

tbh, down here in the southeast quarter, the Atlantic low parked just w of Ireland is not bad. A thundery low will bring less usable conditions and also make sleeping more difficult!  I’ll take that if we can actually squeeze a big storm out ………

[mb018538]

A much more promising week 2 (4th-11t July) from last nights ECM update.

Time longitude plot also shows the strongly negative 500mb anoms in our patch going by then.

[TSNWK]

1 hour ago, mb018538 said:

A much more promising week 2 (4th-11t July) from last nights ECM update.

Time longitude plot also shows the strongly negative 500mb anoms in our patch going by then.

QQ what does green signal please? I'm away in the southwest week commencing 11th July and just starting to try and get an indication of what pattern might be at play then?

[ANYWEATHER]

It looks like the sharp temperature gradient between mainland Europe and the Atlantic will ultimately bring us friend and Foe.! This temperature gradient will spur the Jet Stream to develop lows over or near to the UK.  Yes potentially some warmth at times ,but also a real soaking as well, as this mornings 00z suite shows....

[Guest]

The ECM operational looks slack and thundery next weekend 

[Frosty.]

Wow..it was like pulling teeth ..  …..but the Gfs 0z op finally got there..at T+384 hours… phew..!  

Edited June 24, 2022 by jon snow

[Howie]

35 minutes ago, Steel City Skies said:

The ECM operational looks slack and thundery next weekend 

I was really hoping for a dry and sunny pride weekend  

[FetchCB]

1 hour ago, TSNWK said:

QQ what does green signal please? I'm away in the southwest week commencing 11th July and just starting to try and get an indication of what pattern might be at play then?

I'm guessing and say that green equals no anomaly but what that translates to I'm not sure. 

The EC Ensemble mean for 9th July shows the following 

 

Edited June 24, 2022 by FetchCB
Updated to include Ens Mean

[mushymanrob]

July is set to start fairly average.... which isnt bad.... not overly wet, not overly warm nor cool, cloud on a mild Westerly off the atlantic may be problematic for some, especially Western areas, suniest warmest in the Southeast.. temperatures a comfortable high teens/low 20's.
The big question is.... will the Azores high sit there for long (likely)? or will it displace/ridge Eastwards to bring drier warmer sunnier conditions to our shores?

8-14 day anomaly plus GFS average @ t240 ...

[jules216]

Anybody wants to swap with me next week? Typically GFS now joins EC heat club for Central Europe. This is terrible news after drought we have this year.

[Cambrian]

Atlantic and Pacific flipping their jet stream states over the next week or so on the 0z ECM operational run, but only between weak and more overly fragmented. 

Atlantic jet stream briefly giving it a go at the moment, but all just resulting in a meridional loop with us in the trough lying north-south from Svalbard to Ireland and no real momentum. Very weak Pacific jet. 

 

The trough weakening by day 5, as the pulse of Atlantic energy declines. Pacific jet given up the ghost. 

 

By day 7, the Atlantic jet stream is highly fragmented, no clear steer to the  pattern at all, the trough has hardly mooved all week but has weakened further, and the equally static high pressure cells over the Atlantic and west Russia have also weakened. Pacific jet stream trying to get its act back together, but not enough to fire up anything of note over the Rockies. 
  

A very slack summer pattern, conspicuously lacking any steer with only the slowest moovements, westerly component so weak it can get easily stalled by formation of thundery lows to our south, and insufficient energy in the jet stream to build a decisive high. 

Might be just enough coming out of North America to nudge the Azores high east and set us up in a gentle westerly over the top of a ridge headed close by to our south, finally killing off the trough by day 10, with a little tease of some potential to build into a longer spell of good summer weather influenced by the Azores high. 

 

Edited June 24, 2022 by Cambrian

[Penrith Snow]

Hmmm, looking at this mornings models the weather next weekend looks ok in SE England but decidedly cloudy and damp in the NW with a air flow off the Atlantic.

pressure pattern actually close to normal which TBH isn’t good news for my part of the world ? 

Andy

[Singularity]

We have growing support for an MJO/CCKW propagation across the Maritime Continent (Indonesia) in early July. When the MJO is propagating east across these phases (4-5), AAM tendency has historically been at its most positive. When AAM climbs toward neutral from a very negative starting point in July, there tends to be a shift of anomalously strong high pressure eastward from the Azores to western Europe. It typically weakens SLP-wise once overland due to surface heating (rising air lowering SLP) but remain robust higher up, as evidenced by high 500 mb geopotential heights.

As Tamara described, this is how a more sustained heat build can manifest.

That's how the MJO should really be used as a forecasting tool, rather than relying on composites for particular phases that don't account for whether its an actual MJO/CCKW event (i.e. propagating east) or some other noise (not propagating).

I'm actually worried about what manner of heat build is likely should this MJO/CCKW event manifest. There's a severe marine heatwave affecting the western Mediterranean, while the eastern North Atlantic is mostly warmer than average, so overland temperatures will be able to rise quickly and far, much as seen over western mainland Europe last Fri-Sat. Unusually dry soils are also widespread, further increasing the potential daytime maximums. This 'preconditioning' is quite similar to that which was in place prior to the 2003 heatwave.

Whatever heat build does occur, its longevity will depend on just how high AAM climbs. It feels unlikely that it will make it far above neutral, but you never know - a strong MJO would be able to force that, at least briefly.

Once AAM drops back down, it will come down to the AO & summer NAO; if they are positive then trailing ridges may keep a hot pattern going for maybe a week or so. Current extended ECMWF modelling is suggesting that outcome and it's been consistent for a few updates now - notable given it predicts temperature anomalies 1-3°C across nearly all of Europe, including the UK, for 2nd half July.

[Earthshine]

Warming up and high pressure never far away

[bluearmy]

30 minutes ago, Singularity said:

We have growing support for an MJO/CCKW propagation across the Maritime Continent (Indonesia) in early July. When the MJO is propagating east across these phases (4-5), AAM tendency has historically been at its most positive. When AAM climbs toward neutral from a very negative starting point in July, there tends to be a shift of anomalously strong high pressure eastward from the Azores to western Europe. It typically weakens SLP-wise once overland due to surface heating (rising air lowering SLP) but remain robust higher up, as evidenced by high 500 mb geopotential heights.

As Tamara described, this is how a more sustained heat build can manifest.

That's how the MJO should really be used as a forecasting tool, rather than relying on composites for particular phases that don't account for whether its an actual MJO/CCKW event (i.e. propagating east) or some other noise (not propagating).

I'm actually worried about what manner of heat build is likely should this MJO/CCKW event manifest. There's a severe marine heatwave affecting the western Mediterranean, while the eastern North Atlantic is mostly warmer than average, so overland temperatures will be able to rise quickly and far, much as seen over western mainland Europe last Fri-Sat. Unusually dry soils are also widespread, further increasing the potential daytime maximums. This 'preconditioning' is quite similar to that which was in place prior to the 2003 heatwave.

Whatever heat build does occur, its longevity will depend on just how high AAM climbs. It feels unlikely that it will make it far above neutral, but you never know - a strong MJO would be able to force that, at least briefly.

Once AAM drops back down, it will come down to the AO & summer NAO; if they are positive then trailing ridges may keep a hot pattern going for maybe a week or so. Current extended ECMWF modelling is suggesting that outcome and it's been consistent for a few updates now - notable given it predicts temperature anomalies 1-3°C across nearly all of Europe, including the UK, for 2nd half July.

The ec suites are way less progressive on giving the MJO any amplitude in 4/5 compared to the gefs