Model output discussion - first hot, thundery plume of the summer

[Derecho]

The awful weather two weeks ago will quickly become a blip and distant memory if the ECM 00z comes off. No sign of any extreme rainfall coming anytime soon either... Definately won't be a curtain closer on Summer 2019 if it came off.

If we can tap into that heat to our south then we may get some more warmth. GFS isn't the best but I have seen far worse. Cool and dry for the most part if that came off with some showers on north facing coasts and at times in eastern areas too.

[mushymanrob]

some over reactionary posts here this morning... its july 1st, calling the arrival of autumn based on one fi run is a bit daft imho.. even IF those charts came off theres no saying how long theyd last. there is plenty of time yet for a more summery settled pattern to emerge, after this weeks pleasant summery weather has finished.

[Djdazzle]

This thread is degenerating into a moaners’ paradise. People calling summer over on July 1st. Do people really expect the models to show endless HP to the end of FI on every run?

Complete overreactions and it’s getting boring. People seem to forget that the models flip wildly. ECM and UKMO disagree at T96. Nothing is decided.

[StormChaseUK]

6 minutes ago, Djdazzle said:

This thread is degenerating into a moaners’ paradise. People calling summer over on July 1st. Do people really expect the models to show endless HP to the end of FI on every run?

Complete overreactions and it’s getting boring. People seem to forget that the models flip wildly. ECM and UKMO disagree at T96. Nothing is decided.

I think it is case of people wanting to see "any" High Pressure rather than endless HP.

[Djdazzle]

Just now, StormChaseUK said:

I think it is case of people wanting to see "any" High Pressure rather than endless HP.

Yep but it’s one or two runs. Last night HP was showing. It’s fine to comment on what each run shows but it’s the hyperbole and summer is over statements which spoil an otherwise good discussion.

[danm]

22 minutes ago, 38.5*C said:

The week just gone will quickly become a blip and distant memory if the 6z comes off. No sign of any extreme heatwave coming anytime soon either..  Definately could be a curtain closer on Summer 2019 if it came off.

What an absurd post. If you’re looking for an “extreme heatwave”, you may be waiting a while. The fact they’re “extreme” makes them rare. 

Plus it’s the 1st of July. 

[Norrance]

1 minute ago, Djdazzle said:

Yep but it’s one or two runs. Last night HP was showing. It’s fine to comment on what each run shows but it’s the hyperbole and summer is over statements which spoil an otherwise good discussion.

Quite right and any more Summers over type statements not backed up by model analysis will be removed.

[Methuselah]

So, here we go, with the 06Z GEFS ensembles...which, whilst they mightn't be exactly spellbinding in their collective brilliance, hardly (IMO) justify anyone turning the thread into a modern-day Jonestown?

  

  

 

Edited July 1, 2019 by Ed Stone

[Frosty.]

3 minutes ago, Ed Stone said:

So, here we go, with the 06Z GEFS ensembles...which, whilst they mightn't be exactly spellbinding in their collective brilliance, hardly (IMO) justify anyone turning the thread into a modern day Jonestown?

  

  

 

Indeed Ed, there's an improvement for sure, subtle but it's there.

[johnholmes]

1 hour ago, danm said:

What an absurd post. If you’re looking for an “extreme heatwave”, you may be waiting a while. The fact they’re “extreme” makes them rare. 

Plus it’s the 1st of July. 

Put the poster on 'ignore' it does wonders for the blood pressure. He stays within the rules (just) but is known for his wind-up/provocative posts

[Frosty.]

The cfs 0z operational doesn't show any sign of a sustained anticyclonic spell during July or even well into august that I can detect, it looks changeable / unsettled with a mixture of troughs and transient ridges, temperature wise, nothing special, a mix of warm and cool so pretty average really sums it up..of course, we are talking long range on the cfs and whatever it shows doesn't preclude very summery spells during the next few months.

Edited July 1, 2019 by Jon Snow

[MATTWOLVES 3]

A very positive Jma 0z run, pretty much ties in with exeters thoughts of largely warm settled Conditions away from the NW moving into the middle of July. Not bad at all. 

[Singularity]

20 minutes ago, Jon Snow said:

The cfs 0z doesn't show any sign of a sustained anticyclonic spell during July or even well into august, it looks changeable / unsettled with a mixture of troughs and transient ridges, temperature wise, nothing special, a mix of warm and cool so pretty average really sums it up.

For what it's worth, that's well out of kilter with the recent ensemble mean.

This mean actually does a good job at capturing what may occur as a result of the Nino standing wave trying to move ridges through the UK and NW Europe toward Scandinavia, while the Arctic blocking gets in the way a bit, but isn't able to totally overpower the tropical forcing and cause the Scandi trough to retrogress west or southwest to affect the UK more.

The strength of that trough is a big, and very uncertain, factor here. FV3 keeps really pumping it up, but its known cold bias (which we need to keep in mind when looking at the local conditions too; it makes any pattern look cooler / less warm than it is) could be resulting in too much cold air within the trough circulation, enabling it to grow stronger and last longer than it really should. GEFS also have this bias, but not as strongly.

As usual, this isn't the full picture though... the models are toying with a new MJO wave kicking off in the western IO, for which the composite when there's positive Nino region SSTs makes for ugly viewing. This is likely to be why GEFS isn't offering much inspiring output at the moment.

 

  

However, I'm far from convinced that there will be such a fast, strong impact from this as FV3 and GEFS seem to be suggesting. The observation data keeps rooting the MJO signal in the West Pacific, which implies to me that the strength of the Nino standing wave is exceeding model predictions. The cases used in the composite above  - which are based on the RMM analysis of MJO phase - are likely ones in which the standing wave was very weak, so the IO activity was able to the contribution to the RMM signal. So if the Nino standing wave proves stronger in the next week or two, then that composite won't be valid.

[Frosty.]

The ICON 12z looks great for most of this week with a strong azores ridge bringing fine and increasingly warm weather to at least the southern half of the uk but then there's a change as a trough dives south through scandinavia and our winds become more northerly so temperatures cool down again and it probably becomes more showery, at least further n / e...however, a ridge remains very close to the west and many western areas would likely stay fine, surface conditions actually wouldn't be too bad but nights could become colder than normal for the time of year. 

Edited July 1, 2019 by Jon Snow

[northwestsnow]

15 minutes ago, Jon Snow said:

The ICON 12z looks great for most of this week with a strong azores ridge bringing fine and increasingly warm weather to at least the southern half of the uk but then there's a change as a trough dives south through scandinavia and our winds become more northerly so temperatures cool down again and it probably becomes more showery, at least further n / e...however, a ridge remains very close to the west and many western areas would likely stay fine, surface conditions actually wouldn't be too bad but nights could become colder than normal for the time of year. 

UKMO looks similar to that appraisal Karl, warm/dry then becoming cooler from the north later in the weekend-

 

[StormChaseUK]

The Iceland low will be key to how the weekend will progress. Weaker it is the stronger the warmth for UK will be.

[Methuselah]

A very odd chart at T+198...a lot of what looks suspiciously like nothingness?

  

[Frosty.]

5 minutes ago, Ed Stone said:

A very odd chart at T+198...a lot of what looks suspiciously like nothingness?

  

Something of an east / west split there Ed.. cool & showery east, drier brighter and relatively warmer the further west you go 

Edited July 1, 2019 by Jon Snow

[MATTWOLVES 3]

Interesting Scenario from the GEM going into next week, notice how devoloping low pressure to our SW starts to pump up some very warm conditions... Onto something... Or not.. Could be worth watching. 

[knocker]

Some interesting features of the gfs evolution

At t24 The TPV west of Norway, the trough in the Labrador Strait and the upper low starting to develop in the baroclinic zone west of Portugal

Wind it on 48 hours and the upper low has developed nicely with the adjacent subtropical high ridging north east over the UK. Simultaneously the LS trough is tracking east towards the TPV.

And after a further 48 hours the LS trough has phased with the TPV whilst another trough, that can be seen in the western Atlantic is taking closer order to our low to the SW which initiates a  burst of northward amplification of the subtropical high

And the fait accompli

 

Edited July 1, 2019 by knocker

[Methuselah]

The 12Z GEFS ensembles would suggest only gradual evolutions:

  

  

But overall, slow reduction in SLP as rainfall spikes become more frequent...It is still nearly all in FI, however.

[knocker]

The evolutionary theme of the ecm is not dissimilar to the gfs. albeit some variation in detail. Essentially a dry few days for much of the UK which just about remains under the auspices of a weak ridge but but some frontal incursions do occur and thus the north west is the exception

Edited July 1, 2019 by knocker

[Guest]

31 minutes ago, 38.5*C said:

 

Looks cool, 9c below average is as bad as you can get in July. 

Until then looks like a pleasant week ahead with temps slowly climbing toward the mid twenties for the south with our Azores ridge building in, though to be honest probably no better than average for the north midlands northwards under the influence of more cloud and a surface flow with Atlantic origins. Then pretty much cross model agreement during later Friday and Saturday the Scandi trough will influence our weather lowering temperatures and humidity notably and bringing in more showery activity. Certainly at this range it doesn’t look at though we’ll get stuck in the same rut as early June but with some of the models indicating more NB over Greenland around 240hrs it wouldn’t surprise me. 

Edited July 1, 2019 by shuggee

[MATTWOLVES 3]

I'm non the wiser from viewing ECM... its a complete pigs dinner of a chart, neither are we being dominated by high or low pressure... The boys that can't be named still paint a good outlook, so I'm inclined to side with them at this stage.... Personally I'm expecting a better mean once again with the op being somewhat of an outlier. I'm certainly not seeing a scenario of 9c below average, most definitely not away from the far North. 

[Frosty.]

54 minutes ago, Mattwolves said:

 I'm certainly not seeing a scenario of 9c below average, most definitely not away from the far North. 

Agreed, the 850's on the Ecm 12z operational don't look bad at all, especially further south so plenty of warm weather at least, particularly in any sunshine.

Edited July 1, 2019 by Jon Snow